{
    "system": "GoGuides Verified Text",
    "api_version": "verified-text-v1",
    "status": "ok",
    "response_type": "verified_text_record",
    "source_key": "britannica_1926",
    "source_title": "Encyclopaedia Britannica (1926)",
    "license_code": "public_domain",
    "attribution": null,
    "license_url": null,
    "chunk_id": "1926:refrigeration:e7958cb73897",
    "title": "REFRIGERATION",
    "section": null,
    "hash_alg": "sha256",
    "hash_sha256": "4e6527f3985aeeec8da31c9a2a2a7cd06b01a437679f779dce239ec047ddce35",
    "normalizer": {
        "name": "ggnorm",
        "version": "1.0"
    },
    "verified_text": "by this term is meant the artificial control of the humidity and temperature of the air, or of the temperature of commodities when these temperatures are below that of the atmosphere. in accordance with the second law of thermodynamics (see 26.808) these ends are accomplished by the use of a reversed engine, for, in the refrigerating cycle, heat ts absorbed at the lower temperature and rejected at the upper temperature, a process which is the reverse of that performed by the ordinary heat engine. but similar to the conditions in the steam-engine cycle, a working medium, in this case a refrigerant is used to carry out the cycle of operations. this refrigerant is a volatile liquid such as ammonia, carbon dioxide, sulphur dioxide, butane or propane, but ammonia is used more extensively than any of the others. in the refrigerating cycle, the refrigerant is made to pass into the evaporating coils so as to enable heat to be absorbed from the commodity to be cooled. during the absorption of this heat, the refrigerant 1s evaporated. as it is essential, for reasons of convenience and economy, to return the refrigerant back to the liquid state, the medium must be compressed to such a degree as will enable the liquefaction to occur under atmospheric tem- perature. the result is a closed cycle using the same medium continuously, and the cycle includes a heat-absorbing system at the lower temperature (usually called the refrigerator); a heat- rejecting system at the upper temperature (frequently called the source); a reversed motor, usually a compressor; and a pressure-reducing device, which is preferably an expansion cylinder, but is always a throttling valve when liquids are handled. the theoretical cycle can be brought out clearly by means of an illustrative example:— the problem,—a reversed carnot engine is used for refrigeration. the temperature of the refrigerator is —10°f. and that of the hot body is 8o° fahrenheit. find the horsepower required to drive the motor if 10,000 b,v.u. are to be taken from the cold body per min- ute. the efliciency of the cycle is t,-t o—450 vy o+0 — 10,000 therefore 0-1667 ue te sees the work done, aw =2.000 b,t.u. per minute = 2,000 + 42:44 =47-1 horsepower unit of refrigerattonn—the unit of refrigeration is defined differently in different countries. the british rating is the pro- duction of refrigeration at the rate of 1 calorie per sec., or 342,860 b.t.u. per 24 hours. the american rating is slightly less and is given as the cooling rate of 200 b.t.u. per min. or 288,000 b.t.u. per 24 hours. a machine having such a capacity for cooling is said to have a rating of 1 ton of refrigeration. refrigerants.—according to the second law of thermodynamics all refrigerants (working media) have the same efficiency, al- though this is not achieved in practice, and a large number of volatile liquids, as well as air and steam, have been tried with varying success. at the present time ammonia, carbon dioxide and sulphur dioxide are used in the order named, and air and water are practically abandoned. ammonia is preferred because of its large value of the latent heat of vaporisation and its nom- 319 inal pressure (of less than 200 lb. per sq. in. as a rule). carbon dioxide is preferred on account of its “ safety ”’ factor, as the gas cannot explode, will put out fires, and is practically innocuous. flence carbonic refrigeration is popular in the united states for theatre cooling and marine work. for the latter application the decrease in compressor size, as compared with ammonia machine requirements, the decrcase in weight and the fact that a copper condenser can be used with carbon dioxide without corrosion, are all advantages. sulphur dioxide has no friends in america, except in the case of the 1/20-, 1/ro- and the 1,/6-ton housc- hold machines, whereas in germany, and to a lesser extent in great britain, the sulphur dioxide compressors are used in large sizes. brine or direct expansion.—refrigeration can be accom- plished by two separate methods; by the direct use of the refrig- erant in the cooling coils—direct expansion—and by the use of a non-freezing solution, previously cooled by the refrigerant — the brine system. in cold-storage refrigeration, and in the packing-houses, either system will be found in about the same proportion. when brine is used it is almost always calcium chloride, especially for temperatures below 15° fahrenheit. brine can use ordinary (full weight) piping and the usual fittings for 150-lb. pressure, but direct expansion requires for ammonia special fittings of air-furnace, cast-iron or drop forgings. brine has a cheaper pipe system in first cost, but both supply and return pipes have to be insulated. <a brine circulating pump is required, and brine requires a lower suction pressure on the refrigerating machine than does direct expansion. with the brine system a storage capacity is possible, a factor not possessed by direct expansion, and therefore the refrigerating machine does not have to run continuously. it is considered safer to use brine, as the ammonia cannot, under these conditions, cause damage should an accident occur to the piping. in special cases brine is preferred, as for example, in the case of the chilling of castings, and in brine spray systems in the packing houses. types of compressors.—in marine work the compressor is nearly always a vertical one. in great britain very few horizontal! compres- sors now are being installed, whereas the horizontal, double-acting ammonia and carbon dioxide compressors are common in the united states. in great britain the preferred type of compressor is that with the enclosed crank case, and with 2, 3 and even 4, vertical cyl- inders, designed either for single or double acting. in america the preference appears to be for the twin vertical single-acting enclosed crank case compressor up to 75 tons capacity, and for the use of 3 cylinders in the larger sizes, but the double acting, vertical com- pressor is never used. the horizontal, slow and medium speed double-acting machines are used in sizes of 75 tons capacity and upwards. | . valves.—the valves used in refrigerating compressors have been modified recently, due to the general desire to increase the rotative speed. the old type of poppet valve is not now used to any extent, although the modified type of poppet valve of light weight is used as a ‘“‘balanced\"’ suction valve in the piston, and, when necessary, a number of light-weight poppet valves are used for the discharge. the favourite type of valve is the ring plate valve made of special steel, hardened and ground, or of the thin steel ribbon valve. these valves are placed in cages and are identical for suction and discharge except for the direction of the opening of the valve. the smaller of the enclosed type compressors, both for ammonia and carbon dioxide, have rotative speeds up to 600 revolutions per minute. type of drive-—while the steam engine was formerly the only prime mover, in 1926 the diesel engine or the electric motor, was used almost exclusively for refrigerating machines. the electric motor used is the direct-current type in special cases, but usually the squirrel cage, or the wound rotor type of induction motor. since 1915 there has been a great demand for the synchronous motor, even for such small capacities as 15 tons. when the synchronous motor is used, clearance pockets are frequently installed in the compressor head in order to vary the capacity without shutting down the machine. this can be done without much loss of operating efficiency. cold storage and the packing-house—by keeping fruits, vege- tables, eggs, fish, poultry, and meats in cold storage, the natural processes of decay can be retarded and eatables can be carried over from the period of heavy production to the season when the fresh commodity would be scarce or unavailable. cold storage means the maintenance of a fixed temperature and humidity, at the conditions best suited for the goods being stored. in the packing-house the animal heat must be removed from the 320 carcasses quickly. if put in storage the meat must be kept ata temperature near 32°f, but if shipped to any distance it must be frozen. the average time between slaughtering and con- sumption is slightly more than two months. by means of refrig- eration it is possible to organise large control slaughter houses, under government inspection and the best sanitary conditions, with shipment to all points by means of refrigerator cars. the modern packing-house means wholesome food to an extent impossible with the local butcher. the object of cold storage being economic, there is no object in holding except to preserve the surplus supply until the demand permits its use. although foods may be kept in good condition much longer than the intervals named below, u.s. govt. reports give the average length of storage for various articles as:— fegs . 5-91 months beef 2:28 months dressed poultry 2-42 months mutton 4°45 months butter 4-43 months pork 0:88 months fruits, particularly the apple, can be kept in cold storage satisfac- torily, and the same is true of vegetables like lettuce, celery, potatoes, etc. berries and some soft fruits have been kept in a frozen condition for from 6 to 10 months, and were then reported to be equal to fresh fruit for most purposes. eges, fruit, poultry, fish, etc —commoadities of the best quality only should be put in cold storage, except in the case of eggs frozen in bulk. apples should be held at 31°f. with an average relative humidity of 85%. fresh air circulation does not show any advan- tage, but a lively circulation of air to each individual apple is re- quired in order to reduce scald. the amount of carbon dioxide in the air should be less than 12%. the egg should be kept at a tem- perature of from 29° to 32°f. witha relative humidity of 85%. venti- lation must be provided by careful storing with strips 3-in., or thicker, between the boxes and 2-in. strips on the floor. poultry should be carried at 2°f. or lower, and should be stowed with at least i-in, dunnage. poultry should be dry-picked and dry-packed in clean, well-made boxes, r2 birds to the box, and each one sepa- rately wrapped, and the box lined with a good paper. fish are washed free of dirt and the larger ones are gutted. pans containing about 4o lb, are placed in sharp freezers at from —5° to —15°fahrenheit. as soon as the fish are reduced in temperature they are glazed by being made to pass through a trough of water at 32°f., or they are placed in a grilled platform and are lowered into the water. after glazing, the fish are held at from 0° to 10° fahrenheit. the manufacture of ice-—tyhe use of manufactured ice is becoming more and more a necessity, although in the united states the small household refrigerating machine has been taking to a great extent the place of ice in the cities. the average amount of ice consumption per capita in the larger cities of the united states is estimated at 1,000 lb. per year and this amount is increasing steadily. the use of ‘natural ice diminished during the years 1910-26 very rapidly in the city retail trade because of its uncertainty from year to year, its irregular size and indifferent appearance, and the idea that it is un- sanitary. the bulkiness of artificial ice practically requires its use near the point of its manufacture, although railroad freight and auto- truck shipments expand the range of its use somewhat. ‘the total production in the united states in 1919 was 28,000,000 tons of 2,000 lb. each as compared with 21,000,000 tons in i914. as an estimate has been made that only 3 of the families in the united states at present use ice at all, there appears to be an opportunity for an appreciable increase. in ice-making, mechanical refrigeration is used to the extent of about 1-6 tons of refrigeration per ton of ice (daily capacity). the present preferred system uses deep well or city water, not distilled as formerly, and air agitation during freezing. commercial freezing is accomplished by immersing galvanised iron cans holding 300 and 400 ib. of water in a brine bath held at a temperature of from 14° to 20° fahrenheit. air agitation at from 3 to 12 \\b. per sq. in. pres- sure is resorted to in order that the ice block shali be transparent, a condition required by the retail trade. the brine is kept cold by means of ammonia piping between the cans in the brine, or by the use of the shell and tube brine cooler submerged in the brine in the ice tank. the 300 and 400 ib. cans require from 40 to 45 hours for freezing, and are removed to the dumping platform by means of a travelling crane which handles as a rule from 6 to 24 cans at atime. when electrically driven machinery is used, a ton of ice can be produced with the expenditure of from 35 to 55 kw. hour, depending on the time of the year, the condenscr pressure and other details in the plant. when crushed ice is desired, the manufactured ice <loes not have to be transparent, and the air agitation in the cans can be omitted. cooling of milk and manufacture of ice cream.—when milk is transported some distance, especially for urban distribution, haled by the audience. refugees and the exchange of populations the time between production and consumption is over 24 hours; even frequently 48 hours. this means that it is imperative to cool the milk quickly and to keep it at a temperature of 50°f. or lower. pasteurised milk is becoming more general in use, and refrigeration must be resorted to in all cases where a liberal supply of cold water 1s not available at slight cost and where the use of ice and salt 1s not economical. mechanical refrigera- tion is often resorted to because of its easy control of tempera- ture and its cleanliness. the amount of refrigeration required in cooling milk varies with the rate of cooling, as the desire fre- quently is to hasten the process in order to deliver promptly. roughly, one gallon per min. will require 13 tons of refrigera- tion, assuming that the milk is cooled 30°, say from 70° to 40° fahrenheit. the ice cream industry is increasing rapidly in the united states and great britain. in 1924 the number of wholesale plants engaged in the manufacture of ice cream was estimated at 4,000. the estimate of the u.s. dept. of agriculture for 1920 indicated a total production in that country of 260,000,000 gal., and the rate of factory-produced cream in the cities of from 4 to 5 gal. per year per capita. in the manufacture of ice cream it is usual to allow one ton of refrigeration per 60 gal. of cream, including freezing, harden- ing, storage, etc. calcium chloride brine has been used almost exclusively, at about o° f. in the freezer, but direct expansion is now being used somewhat. the cream is cooled to about 25° in the freezer, and is then placed in containers for storage in the sharp freezer held at from 0° to —1o° fahrenheit. ice cream is usually held in storage for a day or two to improve the flavour. cooling of buildings —public buildings in the larger citics of the united states, like chicago, new york, st. louis, etc., use refrigeration to make the air more comfortable during the hot summer. the method is to utilise the ventilating systems already installed and provide the same amount of air per person, but the air must be cooled from 8° to 15° f. below the temperature of the outside air. too great an amount of air cooling has been found unwise, and the relative humidity should be between 65 and 75 %. for this purpose spray nozzles are employed, using water at about 45° to so° f., and usually direct expansion coils at the entrance to the spray chamber. these coils act as air and water coolers, and no fear of the refrigerant is entertained because of the negligible danger of a panic, or of the after effects to people should even relatively large amounts of carbon dioxide gas enter the auditorium. in theatre ventilation and cooling the amount of recirculated air effects the tonnage, but where 50% of the air is permitted to be returned to the washer to be cleaned and cooled, and the other 50% is fresh air, the load is from 23 to 3 tons of refrigera- tion per 1,000 cu. ft. of air per min. passing through the spray chamber, in localities having summer conditions comparable with chicago. roughly, the amount required to cool and con- dition the fresh air is twice that required to cool the recirculated air. in the latter case the load on the machine is that required to neutralise the effects of heat leakage, the heating effects of the people and the illumination and to condense the moisture ex- (h. j. m.) refugees and the exchange of populations.—in the early history of european civilisation wars and conquests were often followed or accompanied by considerable movements of population. sometimes the two went necessarily together, because the motive for war was the desire for richer lands on which the conquerors wished to live; sometimes the movement of population resulted from the ferocity of the invaders who drove whole populations away from the countries which they had inhabited. refugee movements temporary.—for a long period this feature of warfare dis- appeared, but with the world war of ror4 it once more re- curred. the events of ro14-8 caused greater movements of population from one place to another than there had been for centuries before. in some cases, it 1s true, these movements, refugees and the exchange of populations though large, were only temporary. for example, although the belgian refugees who fled from the german invaders in rg14 were very numerous, and although practically all of them remained away from their homes until the end of 1918, they did not attempt to create a new life or to establish new homes outside their native land; their migration was only temporary, like that of the refugees who fled from the invaded provinces of france and italy. permanent.— but in other cases, great masses of refugees who left their homes when the tide of war swept over them had little prospect of ever returning or of recreating their previous life there. this has been the situation of a considerable proportion of the inhabitants of the balkan peninsula. in that unhappy region of the world, where the population of large areas is mixed in race, great masses of people were obliged, cither by fear of the invading armies or by the hostility of their immediate neighbours, to fly from the places where for centuries they and their forefathers had lived, and once they had left their homes the governments of the countries which they had abandoned made it plain that they would not allow them to return, or that if they did return they would not allow them the means of decent life. faced, therefore, with prolonged, if not permanent exile, the refugees were forced to try to build up a new life in the country to which they had fled. this happened in one case as the result, not of international, but of civil, war. the struggle of 1917 to r9r9 between the white and red armies in russia led to the emigration of great numbers of russians who were subse- quently scattered to every part of the world. in yet other cases the movement of population took place, not as the direct result of military action during a war, but in consequence of the terms of the treaties made when the war ended. but whether they came under about the terms of these so-called ‘‘ exchange of population ” treaties, or whether they were due to the compul- sory or spontancous flight of terror-stricken minorities while hostilities were still going on, these movements of population were due directly to the war. they all presented a number of common features, while collectively they created a great economic and political problem for the exhausted governments of europe. before indicating what has been done to deal with this problem it is necessary to say a few words about its extent. movements—various countries excluding such temporary movements as those of the bel- gians, the emigrations of war refugees of different nationalities were roughly as follows: 1. russians.—between 1917 and 1920 more than 1,000,000 political refugees from russia were thrown upon the charity of europe. some of these refugees were prisoners taken by the ger- mans and austrians during the war, who refused to return to russia. a great number were members of the defeated armies of koltchak, wrangel, denikin and others, many were women and children who fled from the terrors of the bolshevist revolution. when they had time to scttle down theirdistribution was roughly estimatedas follows: germany, 300,000; poland, 400,000; france, 400,000; serbia, 50,000; bulgaria, 30,000; czechoslovakia, 20,000; rumania, greece, at least 50,000; finland, 50,000. in addition a large number—at least 100,000 —fled eastwards into china. 2. greeks —as the result of warlike operations there fled into greece between 1915 and 1922 1,250,000 greek refugees from asia minor and eastern thrace and 50,000 from bulgaria. in addition there came under treaties for the exchange of population from }bul- garia a further 50,000; from asia minor approximately 100,000. 3. armenians,—from the year 1915 onwards there were ex- pelled from their dwellings in asia minor morethan 2,000,000 armen- ians. great numbers of them were either massacred or perished in their wanderings in the mountains; some few succeeded in making journeys on foot as far as mesopotamia; others sought pro- tection in the russian empire. in 1921 the independent armenian republic of erivan, with an armenian population of 800,000, adopted the soviet regime and became part of the federated union of socialist soviet republics. to its original population, 300,000 to 400,000 additional refugees from turkish armenia were shortly added, and in spite of their great suffcring, they were absorbed with remarkable rapidity into the economic system of the country. it is further estimated that more than 300,000 other armenians are scattered more or less in destitution over europe, russia and the near east. in 1921 100,000 fled to syria and have now become syrian subjects in the territory under french mandate; more than ea 60,000 fled in the following year to greece; 20,000 to 30,000 more fled to the republic of erivan. | 4. bulgars.—from 1918 onwards a large number of minorities of bulgarian or quasi-bulgarian race and language fled before the turkish, greek and serbian armies from their homes in the do- brudja, in macedonia and in eastern and western thrace, it is ealculated by the bulgarian govt. that their total number amounts to almost half a million. in addition, about 75,c00 bulgars have voluntarily emigrated to bulgaria from (:reece under the terms of the greco-bulgarian iexchange ef population treaty. 5. lurks.—approximately 50,000 turks fled from eastern thrace and smyrna when these territories were occupied by greek forces in 1919, but returned tothcir homes in 1922. in addition, approximately 350,000 to: 400,000 turks were moved from greece (most of them from macedonia, crete and western thrace) to asia minor under the terms of the exchange of population treaty made at lausanne in 1922. errrcets of refugee movements broadly speaking, the general features of these movements of population may be summarised as follows:— first, the great emigration of russian political refugees has been an almost unmixed evil both for europe and for the refugees themselves. their great suffering has not been compensated by any considerable political or economic gain. this is not equally true, however, of the movement of population in the balkans and in the near east. these movements have at least done a great deal towards the effective unmixing of the populations in these areas. the mixture of populations has led to so much political trouble in modern times that this unmixing process must be regarded as a very considerable advantage. further, in certain countries the influx of refugees, while at first it appeared to be a disaster, is in the long run proving to be a source of strength. this is particularly true of greece, where, thanks to arrangements which will be mentioned shortly, the refugees were absorbed very quickly into the economic system of the country, where they have immensely increased the agricul- tural production and have imported industries hitherto unknown. there is no doubt that they have thus much improved the polit- ical position of greece by giving it a homogeneous and vigorous new population and by increasing the economic wealth of the nation as a whole. it appears probable that the same result will in due course happen in bulgaria, though there the process has been much slower, as the refugees showed less inclination to accept their exile as definitive and to settle down in new homes, than those who went from asia minor to greece. another result of general importance which has followed the movement of population caused by the war is that asia minor has been left almost exclusively to the turks. hitherto in- habited by a very mixed population, including elements which continued the traditions of the ancient civilisation of byzantium, there are now few of these elements left. these changes, whether they be good or evil, have only come about at the cost of terrible suffering to all the individuals con- cerned. this is true even of those who have been moved under treaties of exchange, though of course their sufferings have been much less than those who fled before invaders. it is the personal aspects of refugee movements which generally dominate the minds of people when they consider refugee questions; and no doubt these personal aspects are of supreme importance, not only on account of the claim of the refugees to the humanitarian sympathy of every civilised man and woman, but also because it is the personal problems of individual refugees, which when they are taken collectively, make up the economic problems which their movements cause. and the economic problems brought upon the governments of europe by refugee movements since the war have been of great importance. in many countries they have seriously over-flooded the labour market, and in a number of centres the arrival of vast masses of strangers, wholly destitute and unable to find employment, threw a great burden on the financial resources of the states to which they came, whose governments, unwilling to see them die of starvation, were literally obliged to furnish them with doles from their national funds. this part of the problem is, however, much affected by the so-called treaties for the exchange of popula- tion, on which, therefore, it is necessary to say a word. a2> treaties of exchange-—under these treaties, the most impor- tant of which are the greco-turkish and the greco-bulgarian, impartial committees, consisting of one representative from each government and two or three impartial experts appointed by the league of nations, supervise or actually carry out the trans- portation of the persons moved from one country to the other, value their property, keep an exact record of it and establish their claim for this value against the government of the country to which they go. these treaties of exchange have worked with varying success. so far as the greco-turkish treaty is concerned, its principal and most necessary efiect was to make room in greece, by the removal of 350,000 turks, for a great part of the incoming flood of refugees, who found in the evacuated turkish prop- erties fields and houses ready for their use. without this treaty of exchange, the absorption of the greek refugees into produc- tive employment in their motherland could never have been done. on the other hand, the fate of the turks transported under the treaty from greece into turkey appears to have been less happy. official information cannot be had, but persistent rumours allege that alilhough there were also in turkey many empty properties for the incoming turks, the arrangements have been so defective as to inflict grave losses on them. of the greco-bulgarian treaty of exchange, it is enough to say that while the working of its machinery has been slow, it has already laid the foundation for an unmixing of the population in greek macedonia and in parts of bulgaria, which in the long run, though at the cost of great personal suffering, is likely to lead to satisfactory results. work of the league of nations the other personal and economic problems which have been raised by the refugee movements above described have been dealt with partly by individual governments and partly by the league of nations. to take the russians first, many governments throughout europe accorded them particular privileges and gave them much state help—in particular serbia and bulgaria deserve mention. the league of nations also played a considerable part through the action of the delegations which it established in constantinople and in bulgaria, greece, serbia, germany, poland, france and other countries, in breaking up the most disastrous congestions of refugees in places where no employment could be found, for example, in constantinople and greece; in securing for the refugees in many countries legal protection, freedom of move- ment in search of employment and a new form of so-called ‘“ league of nations passport ” under which they were enabled to travel from one country to another; and even in securing for a small number who desired it, repatriation to their native land. under the auspices and with the help of these league offices, large movements of russian refugees were carried out to france, to the united states, to canada and to other coun- tries where employment could be found. for the greek refugees the league has done still more. through its machinery a loan of £12,000,000 for their settlement in agri- cultural and other employment was obtained, and under the international control of a league commission this settlement has been carried out with remarkable success. on june 12 1926 the council of the league of nations announced their intention of providing a loan of {2,250,000 to the bulgarian government to assist the settlement of the bulgar refugees. the conditions for administration and security were similar to those laid down in the case of the greek refugee loan. for the armenians the same passport privileges and legal protection were obtained through the machinery of the league as had previously been obtained for the russians. their dis- persal from places where they were concentrated in too great numbers, for example, from greece, was also assisted by the agents of the league. the effect of this league of nations action is likely to be cumulative, and considerable as are its short period results in mitigating the sufferings of the refugees and in helping to solve the economic problems caused to the governments concerned, regina—reims its long period results are likely to be more important still. by the various kinds of action which it has undertaken, the league has helped to remove centres of disaffection and discontent; it has helped to build up the prosperity of different portions of the world; and it has helped to raise, by the distribution and settlement of industrious and highly educated refugees, the standards of civilisation in various portions of the globe. it is, therefore, possible to say that, as the result of the generosity of a number of governments and of their enlightened co-opera- tion through the machinery of the league, the ultimate re- sults of the refugee movements will be better than even the most optimistic could have ventured to expect. birliograpiity.—ll.eague of nations official! journal, 3rd year, nos. 3, 4, 7; 11 and 12; 5th year, nos. 3-12; 6th year, nos. 2, 3, 4, 7 and io. . (f. n.) regina, canada (see 23.39), the capital of the province of saskatchewan, increased its population from 2,244 in rgor to 34,- 432 in 1921. the city has a large distributing trade and is the central market for an agricultural region. it is on the canadian pacific and canadian national railways, and has 12 radiating lines. there are many mills, banks, wholesale houses and fac- tories, including a large oil refinery. an annual exhibition is held in a big exhibition park. extensive buildings for the provin- cial government have been erected in a park of 160 ac. on the south bank of the wascana lake. regina is the western head- quarters of the royal canadian mounted police. rehan, ada (1860-1916), american actress (see 23.48), died in new york city jan. 8 1916. reid, sir george (1841-1913), british painter (see 23.50), died at oakhill, somerset, feb. 9 1913. reid, sir george houston (1845-10918), australian poli- tician, was born feb. 25 1845 at johnstone, renfrewshire, and emigrated in 1852 to australia. he practised as a barrister in svdney and was elected to the n.s.w. parliament in 1880. in 1883-4 he was minister of public instruction and from 1891-4 was leader of the free trade party. in 1894 he became premier and retained office until 1899. reid played a conspicuous part in the federation movement and was a member of the first common- wealth parliament of 1901, leading the free trade opposition to sir edmund barton. in 1904 he became prime minister, but he stood for a programme which was unacceptable to a predomi- nantly protectionist country, and after his fall in the following year he never again held office. he led the opposition from r905— 8 and in the latter year retired from australian politics. created k.c.m.g. in 1909, in the same year he was appointed high commissioner in london; and on the expiration of his term sat in the house of commons as conservative member for st. george’s, hanover square, london, till his death sept. 12 1918. reid, whitelaw (1837-1912), american journalist and diplomatist (see 23.52), died in london dec. 15 1912. his last public address was delivered before the students of the univer- sity college of wales, aberystwyth, on thomas jefferson. in 1912 appeared the scot in america and the ulster scot, and posthumously, in 1913, american and english studics. see royal cortissoz, the life of whitelaw reid (1921). reims, france (see 23.53), with a population of 76,645 in 1921, as compared with 102,800 in 1906, suffered severely during the world war. the german advance of sept. 1914 brought the enemy within cight miles of the town, which was heavily bom- barded and the population sheltered in the huge subterranean wine-cellars, where dormitories were made, schools were held and a daily paper was published. in easter week, 1917, more than 25,000 shells fell on the town and the civilian population who remained—some 17,000 persons—were evacuated. reims was one of the objectives of the germans in 1918, but, though they got within two miles of it, the town held out until freed by the allied offensive in october. reims was then in ruins; it is said that less than a hundred houses remained undamaged. the place royale, the rue de vesle, the hotel de ville, the churches of st. remy and st. jacques and the archbishop’s palace, were burnt out or in ruins. the cathedral had been heavily shelled, under the pretext that the towers were used as. reinach—rejuvenation observation posts (which was denied by the archbishop) and was gravely damaged, especially on the southwest side. reims in 1926 was still a long way from complete recovery, and new buildings were everywhere interspersed with ruins and open spaces. the cathedral was in process of careful restoration; as many as possible of the statues will be reassembled, and the nave roof will be strengthened with concrete. considerable progress has been made here and on the facade, mr. j. d. rockefeller having given 5,000,000 fr. towards the work, but it was reckoned in 1922 that complete restoration would take some 30 years, and much of the detailed work is irreparably lost. part of the north aisle is in use as a temporary church. the statue of st. joan of arc, which stood in front of the cathedral, was removed during the war for safety, and replaced in 1921; many of the art treas- ures, tapestries, etc., were also saved. light railways, starting from the gare des promenades, have been built to various spots on the battlefields. strong efforts have been made to rehabilitate the wool spinning industry. reinach, joseph (1856—1921), french author and politician (see 23.55), died in paris april 18 1g2tr. re-inforced concrete: sec ferro-concretf. engineering. reinhardt, max (1873- ), german stage and theatrical manager, was born at baden near vienna, sept. 9 1873. he studied under emil biirde and began his theatrical career in a theatre in salzburg. in 1894 he went to berlin, where he was one of the founders of the kleines theater (1902). in 1903 he became manager of the neues theater and from 1905-20 was director of the deutsches theater, berlin, which was connected with the kammerspiele. ife was also in 1919~20 director of the grosses schauspielhaus in the same city. at the deutsches theater, with the help of a company of excellent actors, including wegener and bassermann, he put into practice his ideas of a new art of the theatre. he aimed at ensemble effects and the uni- fication of rhythm of speech, gesture, scene and background, tone, colour, costume and movement. reinhardt achieved fame in england as the producer of sumeftrun (1911), of the afiracle at olympia, london (1911-2), and of ocdipus rex (1912). in addition to his interests in berlin, reinhardt also owned theatres in vienna and salzburg. rejane, gabrielle (1857-1920), french actress (see 23.58), died in paris june 14 1920. during the world war she visited england and acted in patriotic plays in london. she was made chevalier of the legion of honour for her war services. rejuvenation.— post-mortem examinations of many hun- dreds of cases where great age has been attained reveal invariably the same histological changes, diminution and atrophy of the functional cells, augmentation and hypertrophy of the tissue cells and of the fibrous tissues. physiological equilibrium is lost, energy disappears, and the cellular activity is no longer ade- quate for the maintenance of life. in vivre, published in 1920, (an hypothesis was put forward which is in accordance with the views expressed by metchnikov, by which ‘‘ conjunctive tissue forms a support of scaffold work for the func- tional cells of all organs in which are found epithelial cells, which are cells specialised to the work of the respective organs. the conjunc- tive tissue provides the organs with the plasma they need as nourish- ment, which it in turn gets from the capillary system by osmosis. their work is purely passive, they are less fragile, and retain at all stages their power of regeneration, while the highly specialised func- tional cells wear out more quickly and lose their power of recupera- tion. there comes a time when the conjunctive cells which are still energetically reproductive come into contact with functional cells which have lost their power and are doomed to atrophy. ‘the con- junctive cells are naturally incapable of discharging specialised func- tions, so that the organism becomes progressively weaker till the functional cells fail to assure vital equilibrium, and in this contest after valuable collaboration the epithelial cells are worsted by ele- ments which are less perfected, and are unable to secure the due functioning of the several organs of the body, so that old age and death ensue. not only do the functional cells diminish while the conjunctive cells increase, but they also undergo a regressive evolu- tion.” in all multicellular animals the process of regencration, growth andrejuvenation isconstant as is shown typically by the hair and nails. it is now possible to cultivate tissues in suit- able media (see tissue culture) and to keep them alive long 323 after the death of the parent organism. this proves that death is not the inevitable end of cellular vitality, but is in every case the result of unfavourable conditions to which the cells are subjected at a given moment. obviously, scrupulous attention to personal hygiene can do much to secure favourable conditions for the activity of the organs, but it cannot struggle with success against the regressive evolution of the cells which is brought about by old age (see death). the endocrine glands produce substances (hormones), which they pour into the circulatory system and thereby iniluence the metabolic processes, the growth and morphology of the cells. one of these glands should have as its special function the secretion of a substance which gives tone and stimulus to cellular vitality during a certain period of life and ceases to do this on the approach of old age. this cannot be the special function of either the thyroid, parathyroid, pituitary or suprarenal glands, since they continue to act during old age. the only gland which constitutes an exception to this rule is the genital gland. it plays a double rele. it secretes spermatozoa externally, and it secretes internally hormones which it passes into the blood stream, ac- tively at puberty and during maturity, but less and less there- after,so that the diminution and disappearance of its activity correspond with old age. examination of male vertebrate animals after removal of the genital glands shows distinctly the nature of the influence of the internal secretion of these glands on the whole organism as affecting, not only the secondary male sexual characters, but also the growth and development of the body as a whole, the brain and skin cells, the bones and tissues. the physical and intellectual qualities of animals and of man are as intimately conditioned by the hormone secreted by the testicles as are the secondary sexual characters. characteristics of fhunuchs—pyersonal observation of a num- ber of eunuchs in egypt shows that their cranial capacity is be- low normal, their intelligence is less than the average and slug- gish, the memory is weak. they are prone to subterfuge, always a mark, as dr. dartigues has shown, of mental weakness. as to eunuchs who have played a conspicuous part in history, in dip- lomacy, and in war, they were men reduced to that state not in infancy but after attaining maturity, so that the hormone secre- tion would have operated on their mental development. the skeleton is affected by the removal of the testicles and their hormonic activity. ‘the long bones, such as the tibia and femur, ossify much more slowly, and eunuchs are taller than the average of their race. the cranium is reduced in size. the face is nar- rower and all the bones more fragile. the shoulder blades are slender and the pelvis enlarged. the cartilages of the larynx do not ossify, and retain their infantile structure. the adam’s apple docs not project as is usual. clearly the removal of the testicles before the completion of bodily growth modifies the whole bony structure, and proves the preponderating influence of the testicular hormone on the architecture of the skeleton. the effect of these hormones on the metabolism of the body, the chemical transformation of substances assimilated by the organism, is also general, since, as marignan has shown, the glycogen content of ‘‘ entires”’ is greater than that of animals which have been castrated. reduction of muscular development is accompanied by an increase of adipose tissue, which is spread over the whole body but is specially marked in the mammary region, the abdomen and the buttocks. the skin is affected by castration; eunuchs have a pale tint, and their hair goes at an early age. there can thus be no doubt as to the nature of the relation between the gencral reduction of the forces of the organism and the disappearance of the internal secretion of the testicles. no organ can keep its vital energy and yield a full return if the cells are not stimulated and vivified by the testicular hormone. it acts more or less directly on other endocrine glands, since castration is followed by hypertrophy of the anterior lobe of the pituitary gland and by regression of the thyroid body and epiphysis. if the genital glands remained active in old age, were 1 rejuvenation by grafting, serge voronoff, 324 they not the only glands which cease to secrete hormones, old age would certainly be delayed. eunuchs in cairo who had been castrated at an early age and had therefore never been exposed to the activity of the testicular hormones, were never known to have been more than 6oat death. all had the appearance of old men, with desiccated skins, hag- gard eyes, bent, and looking like centenarians. they die between soand 60, prematurely old, long before the term normally reached by their fellows. it is obvious that the deprivation of the internal secretion of the testicles accelerates the advance of old age and shortens life. the only remedy is to graft a young testicle, whether that of a young human being or of an ape, by which the tone-giving substance is provided, so as to increase the vitality of all the cells which are weakened but are not yet atrophied and therefore still able to renew themselves, and thus effectively to rejuvenate the whole organism. so long as an organism, however old, con- tinues to exist, its cells continue to be renewed and rejuvenated. unfortunately, in old age this process of rejuvenation is slowed down, a certain number of the functional cells regress and are replaced by conjunctive tissue. not every cell is atrophied. were this to happen life would stop. the cells which escape this are renewed more slowly, but continue to be renewed to the extreme limit of their vitality. with a rich addition of the testicular hormone, the cells ac- quire new energy, grow more rapidly, proliferate more intensely and rejuvenate the whole system. at the end of several years the beneficent action of the grafted gland is exhausted because the grafts in turn are subject to positive regression. the organism ts again deprived of the stimulating hormones and the symptoms of old age reappear. in most cases testicular grafting is adequate, but in some cases thyroid grafts have to be added, as stated in vivre. see s. voronoft, rejuvenation by grafiing (1925). (5. v:) relativity.—the progress of physical science during the first quarter of the present century was specially remarkable for the general acceptance by the scientific world of the principle of relativity, as expounded by prof. albert einstein, professor of physics in the kaiser wilhelm institut, berlin. its meaning and its history as part of present-day physical theory are the object of this discussion. introductiouw—the primary aim of the investigator in pure science is the discovery of natural laws. as a secondary and hardly less important aim, he tries to invent a mechanism which shall account for the laws already known. the secondary aim is forced upon him partly by the constitution of the human mind; our intellects, unsatisfied with a mere accumualtion of facts, impel us ever to search for the causes underlying the facts: vere scire est per causas scire. but to the working scientist che dis- covery of a mechanism has an additional and more practical value. when he has found a mechanism which will account for certain laws, he can proceed to examine the complete set of laws which the mechanism demands. if his mechanism corresponds with suflicient closeness to reality he may in this way be led to the discovery of new natural laws. on the other hand, the new laws deduced from the supposed mechanism may be false. if the falsity of the new laws is not at once revealed science may for a time be jed into wrong paths. when more accurate experi- menting or observation discloses that the laws are not true a recasting of ideas becomes necessary, and the branch of science concerned may experience a time of revolution followed by a period of rapid growth. an obvious illustration of these general statements is provided by the history of astronomy. the laws of the motions of the planets, as observed from the earth, were tolerably well known to the greeks. they had also evolved an explanatory mechanism starting from the metaphysical premise that the paths of the planets must necessarily be circles. the earth was the centre of the universe and round this revolved spheres to which the planets were attached. to explain the retrograde motion of the outer planets, these were supposed attached to secondary spheres revolving about points on the primary spheres which in relativity turn revolved about the earth. this mechanism of cycles and epicycles as an explanation of planetary motion held the field for eighteen centuries. finally the observations of tycho brahe provided a test which revealed the falsity of the whole structure. the position of mars was found to differ from that required by the mechanism of epicycles by an amount as great as eight minutes of are. out of these eight minutes,” said kepler, “we will construct a new theory that will explain the motions of all the planets.” the history of the succeeding century of astronomy need not be recapitulated here (see 2.811). the earth yielded its place as the centre of the universe, and the structure of cycles and epi- cycles crumbled away. the laws of planetary motion were determined with a precision which for the time appeared to be final. the mechanism underlying these laws was supposed to be a “ force ”’ of gravitation. this force was supposed to act between every pair of particles in the universe, its intensity varying directly as the product of the masses of the particles and inversely as the square of the distance separating them—the famous law of newton. in science, history repeats itself. recent years have provided a further instance of the general processes we have been consider- ing. under the newtonian mechanism every planet would describe a perfect ellipse about the sun as focus, and these elliptic orbits would repeat themselves indefinitely except in so far as they were disturbed by the gravitational forces arising from the other planets. but, after allowing for these disturbing influences, levertier found that the orbit of the planet mercury was rotat- ing in its own plane at the rate of 43 seconds a century. various attempts have been made to reconcile this observed motion with the newtonian mechanism. the gravitational forces aris- ing from the known planets were demonstrably unable to pro- duce the motion in question, but it was possible that mercury’s orbit was being disturbed by matter so far unknown to us. investigations were made as to the disturbance to be expected from various hypothetical gravitating masses—a planet or a ring of planets between mercury and the sun, a ring of planets outside the orbit of mercury, a belt of matter extended in a flattened disc in a plane through the sun’s centre, an oblateness greater than that suggested by the shape of the sun’s surface, in the arrangement of the internal layers of the sun’s mass. in every case the mass required to produce the observed disturbance in the motion of mercury would have also produced disturbances not observed in the motions of the other planets. the solution of the problem came only with the theory of relativity. just as tycho’s eight minutes of arc, in the hands of kepler and newton, revolutionised mediaeval conceptions of the mechanism of the universe, so leverrier’s 43 seconds of arc, in the hands of einstein, has revolutionised our roth-century conceptions, not only of purely astronomical mechanism, but also of the nature of time and space and of the fundamental ideas of science. the history of this revolution is in effect the history of the theory of relativity. it falls naturally into two chapters, the first narrating the building of an earlier physical theory of relativity, and the second dealing with the extension of that theory to gravitation. the physical theory of relativity ——the earliest successful attempt to formulate the laws governing the general motion of matter is found in newton’s laws. the first law states that:— every body perseveres in its state of rest or of uniform motion in a right line unless it is compelled to change that state by forces impressed thereon, in this law no distinction is made between rest and uniform motion in a straight line, and the same is true of the remaining jaws. hence follows the remarkable property to which newton draws explicit attention in his fifth corollary to the laws of motion :— the motions of bodies included in a given space are the same among themselves, whether that space ts ai rest, or moves uniformly forwards in a right line without any circular motion. as a concrete application of this principle, newton instances ‘‘ the experiment of a ship, where all motions happen after the relativity same manner whether the ship is at rest or is carried uniformly forward in a right line.” just as a passenger on a ship in a still sea could not determine, from the behaviour of bodies inside the ship, whether the ship was at rest or moving uniformly forward, so we cannot determine from the behaviour of bodies on our earth whether the earth is at rest or not. we believe the earth to be moving round the sun with a speed of about 30 km. a second, so that there can be no question of the earth being permanently at rest, but we are unable to determine whether it is at rest at any specified point of its orbit, or, in the probable event of its not being at rest, what its absolute velocity may be. there is no more reason for thinking the sun, than the earth, to be at rest. newton wrote as follows:— it is possible that in the remote regions of the fixed stars, or per- haps far beyond them, there may be some body absolutely at rest, but impossible to know, from the positions of bodies to one another in our regions, whether any of these do keep the same position to that remote body. it follows that absolute rest cannot be deter- mined from the position of bodies in our regions. the above quotations are all from the first book of the prin- cipia mathematica. previous to them all newton writes: “i have no regard in this place to a medium, if any such there is, that freely pervades the interstices between the parts of bodies.” the two centuries which elapsed after the publication of the principia witnessed a steady growth of the belief in the reality of such an all-pervading medium. it was called the aether, and by the end of these two centuries (1887) it was almost univer- sally believed that light and all electromagnetic phenomena were evidence of actions taking place in this acther, light from the most distant stars was supposed to be transmitted to us in the form of wave motions in the aether, and we could see the stars only because the sea ‘of aether between us and these stars was unbroken. it had been proved that if this sea of acther existed it must be at rest, for the alternative hypothesis that the aether was dragged about by ponderable bodies in their motions had been shown to be incompatible with the observed phenomenon of astronomical aberration and other facts of nature (see 1.292). on this view it was no longer necessary to go to newton’s “ remote regions of the fixed stars, or perhaps far beyond them,” to find absolute rest. a standard of absolute rest was provided by the aether which filled our laboratories and pervaded all bodies. owing to our motion it would appear to be rushing past us, although without encountering any hin- drance—‘ like the wind through a grove of trees,”’ to borrow the simile of thomas young. the determination of the absolute velocity of the earth was reduced to the problem of measuring the velocity of an acther current flowing past us and through us. in this same year (1887) the first experimental determination of this velocity was attempted by the chicago physicist a. a. michelson. the velocity of light was known to be, in round numbers, 300,000 km. a second, a velocity which was believed to represent the rate of progress of wave motion through the aether. if the earth were moving through the aether with a velocity of 1,000 km. a second, the velocity of light relative to a terrestrial observer ought to be only 299,000 km. a second when the light was sent in exactly the direction of the earth’s motion through the aether, but would be 301,000 km. a second if the light was sent in the opposite direction. in more general terms, if the earth were moving through the aether, the velocity of light, as measured by a terrestrial observer, would depend on the direction of the light, and the extent of this dependence would give a measure of the earth’s velocity. the velocity of light along a single straight course does not permit of direct experimental determination, but the same property of depen- dence on direction ought to be true, although to a less extent, of the average to-and-fro velocity of a beam of light sent along any path and then reflected back along the same path. it was through this property that michelson attempted to measure the earth’s velocity through the aether. the apparatus was simple in principle. a circular table abcd (cf. fig. 1) was arranged so as to be capable of slow rotation about its centre o. light sent along co was divided up at o into two beams which were made to travel along perpendicular radii oa, ob. the 325 arms oa, ob were made as equal as possible and mirrors were placed at a and b to reilect the beams of light back to o. an extremely sensitive optical method made it possible to detect even a very slight difference in the times of the total paths of the two beams from o back to o. there would in any case be a difference owing to the necessarily imperfect equalisation of the lengths of the arms oa, ob, but if the earth is moving through the aether in some direction op, and if the table is made to rotate slowly about o, then this difference ought itself to vary on account of the earth’s motion through the aether. michelson, and afterwards michelson and morley in collab- oration, attempted to estimate the amount of this variation. no variation whatsoever could be detected, although their final appara- tus was so sensitive that the variation produced by a velocity through the aether of even £ km. a second ought to have shown itself quite clearly. thus to the question ‘“‘ what is our velocity through the aether?”? nature appeared to give the answer ‘‘ none.” it was never suggested that this answer should be accepted as final; it would have brought us back to a geocentric universe. clearly either the question had been wrongly framed or the answer wrongly interpreted. it was pointed out in 1893 by fitzgerald, and again independently, in 1895, by lorentz, that the null result of the michelson-morley experiment could be explained if it could be supposed that motion through the aether altered the linear dimensions of bodies. 0 pe 2 pp fig. 1. fig, 2. to be explicit, it was found that the experiment would invariably and of necessity give a nui! result if it was supposed that every body moving through the aether with a velocity # was contracted in the direction of its motion in the ratio eo c¢ being the c velocity of light. the supposition that such a contraction occurred was not only permissible—it was almost demanded by electrical theory. for lorentz had already shown that if matter were a purely electrical structure, the constituent parts would of necessity re- adjust their relative positions when set in motion through the aether and the final position of equilibrium would be one showing precisely the contraction just mentioned. on this view, there was no prima-facie necessity to abandon the attempt to measure the earth’s velocity through the aether. the answer to the problem had merely been pushed one stage farther back, and it now became necessary only to measure the shrinkage of matter produced by motion. it was obvious from the first that no direct material measurement could disclose the amount of this shrinkage, since any measuring rod would shrink in exactly the same ratio as the length to be measured; but optical and electrical methods appeared to be available. experi- ments to this end were devised and performed by rayleigh, brace, trouton and noble, trouton and rankine and others. in every case a null result was obtained. it appeared then that if the earth moved through the aether this motion was concealed by a universal shrinkage of matter, and this shrinkage was in turn concealed by some other agency or agencies. | at this time the word “ conspiracy ” found its way into the technical language of science. there was supposed to be a conspiracy on the part of the various agencies of nature to pre- vent man from measuring his velocity of motion in space. if this motion produced a direct effect « on any phenomenon, the other agencies of nature seemed to be in league to produce a countervailing effect —x. a long train of experiments had not revealed, as was intended, our velocity through the aether; they had merely created a conviction that it was beyond the power of man to measure this velocity. the conspiracy, if such there was, appeared to have been perfectly organised. 326 a perfectly organised conspiracy of this kind differs only in name from a law of nature. to the inventor who tries to devise a perpetual-motion machine it may well appear that the forces of nature have joined in a conspiracy to prevent his machine from working, but wider knowledge shows that he is in conflict not with a conspiracy, but with a law of nature—the conserva- tion of energy. in 1oo05 einstein, crystallizing an idea which must have been vaguely present in many minds, propounded the hypothesis that the apparent conspiracy might be in effect a law of nature. he suggested, tentatively, that there might be a true law to the effect that ‘it is of necessity impossible to determine absolute motion by any experiment whatever.” this hypothetical law may again be put in the equivalent form: ‘the phenomena of nature will be the same to two observers who move with any uniform velocity whatever relative to one another.” this may be called the hypothesis of relativity. the hypothesis in itself was not of a sensational character. indeed, from the quotations which have already been given from newton’s works, it appears probable that newton himself would have accepted the hypothesis without hesitation: he might even have regarded it as superfluous. the true significance of the hypothesis can only be understood by a reference to the scientific history of the two centurics which had elapsed since newton. the newtonian view that absolute rest was to be found only “‘ in the remote regions of the fixed stars, or perhaps far beyond them,”’ had given place to a belief that absolute rest was to be found all around us in an aether which permeated all bodies. what was striking about the hypothesis was its impli- cation—either that we could not measure the velocity relative to ourselves of a medium which surrounded us on all sides, or else that no such medium existed. the hypothesis demanded detailed and exhaustive examina- tion. it was for the mathematician to test whether the hypothe- sis was in opposition to known and established laws of physics, and to this task einstein, lorentz and others set themselves. if a single firmly established law proved to be in opposition to the hypothesis, then of course the hypothesis would require to be abandoned. it was unlikely that such an event would occur among the well-established laws, for if it did, the phenomena governed by that law would enable direct measurement to be made of the earth’s velocity through the aether, a measurement which had so far eluded all attempts of expcrimenters. it was among the more obscure and less well-established laws, if any- where, that discrepancies were to be looked for. it is impossible here to give a complete account of the many tests to which the relativity hypothesis has been subjected. the result of all can be summed up in one concise and quite general statement:—wherever the hypothesis of relativity has appeared to be in conflict with known or suspected natural laws further experiment, where possible, has without a single exception shown the laws to be erroneous, and has moreover shown the alternative laws suggested by the hypothesis of relativity to be accurate. it is only in somewhat exceptional cases that the hypothesis of relativity of itself suffices to determine fully the form of a natural law; these cases constitute the most striking triumphs of the theory. as instances may be mentioned the determination of the law connecting the mass of an electron with its velocity; of the law expressing the velocity of light through a transparent medium in motion (fizeau’s water-tube experi- ment); and of the formulae for the magnetic forces on moving dielectric media (experiments of eichenwald and h. a. wilson).! before passing on from the general statement which has been made, particular mention must be made of one special case. a natural law which, at an early stage, was seen to be in conflict with the hypothesis of relativity was newton’s famous law of gravitation—namely, that every particle of matter attracts every other particle with a ferce proportional to the product of the two masses, and to the inverse square of their distance apart. 1for references to the original papers dealing with these and other tests of the hypothesis of relativity see cunningham, 7he principle of relativity, or j. h. jeans, afathematical theory of electricity and magnetism (4th or 5th ed.). relativity either, then, newton’s great law had to be abandoned, or else the hypothesis of relativity had to be discarded, in which case it would immediately become possible, in theory at least, to determine the earth’s velocity through space by gravitational means. it is the choice between these two alternatives that has led to the most surprising developments of the theory of relativ- ity; and to these we shall return later. space and time.—the hypothesis of relativity, as has already been explained, postulates that the phenomena of nature will be the same to any two observers who move relative to one another with any uniform velocity whatever. the hypothesis has been so amply tested as regards all optical and electromag- netic phenomena that no doubt is felt, or can rationally be felt, as to its truth with respect to these phenomena. the hypothesis can be examined and developed in two opposite directions. we may, on the one hand, proceed from the general hypothesis to the detailed laws implied in it; this has already been done, with completely satisfactory results as regards confirmation of the hypothesis. or we may regard the hypothesis of relativity as being itself a detailed law, and attempt to generalise upward to something still wider. it is this possibility which must for the moment claim our attention. in 1905 einstein examined in full the consequences of the hypothesis that one simple optical phenomenon—namely, the transmission of a ray of light in free space—was, in accordance with the hypothesis of relativity, independent of the velocity of the observer. if an aether existed, and provided a fixed frame- work of reference, then light set free at any instant would ob- viously travel with a velocity which would appear to an observer at rest in this aether to be the same in all directions, and the wave front at any instant would be a sphere having the observer as centre. on the hypothesis of relativity the phenomenon of light transmission must remain unaffected by the motion of the observer so that the light must appear, to a moving observer also, to travel with a uniform velocity in all directions, and thus to the moving observer also the wave front must appear to be a sphere of which he will be the centre. it is, however, quite obvious that the same spherical wave front cannot appear, to each of two observers who have moved some distance apart, to be centred round himself, unless the use either of the common conceptions of science or of the ordinary words of language is greatly changed. in fig. 2 it is not possible, in ordinary language, that both o and p should at the same instant be at the centre of the sphere a b c. the change to which einstein was forced is one which has an intimate bearing upon our fundamental con- ceptions of the nature of space and time; this change it will be necessary to explain in some detail. suppose that two observatories, say greenwich and paris, wish to synchronise their clocks, with a view to, let us say, an exact determination of their longitude difference. paris will send out a wireless signal at exact midnight as shown by the paris clock, and greenwich will note the time shown by the greenwich clock at the instant of receipt of the signal. green- wich will not, however, adjust their clock so as to show exact midnight when the signal is received; a correction of about -oor second must be made to allow for the time occupied by the signal in traversing the distance from paris to greenwich. to turn to mathematical symbols, if fp is the time at which a signal is sent out from one station, the time of receipt at a second sta- tion is taken to be bots, where x is their distance apart, and c is the velocity of light. this represents the ordinary practice of astronomers, but it is clear that if the earth is travelling through a fixed aether with a velocity # in the direction of the line joining the two observatories, the velocity of transmission of the signal relative to the two observatories will not be ¢ but a ctu thus it appears that it is impossible to synchronise two clocks unless we know the value of #, and that the ordinary practice of astronomers will not, as they expect, synchronise their clocks, c+, and the time of receipt at the second station will be fo + relativity but set them at an interval apart equal to loa) hich sa eeheea.s lto “ which may, to an approximation, be put equal to “2 according to the hypothesis of relativity, it is impossible ever to determine the value of #, and soit is impossible ever truly to synchronise two clocks. moreover, according to this hypothe- sis, the phenomena of nature go on just the same whatever the value of #, so that the want of synchrony cannot in any way show itself—in fact, if it did, it would immediately become pos- sible to measure the effect and so arrange for true synchrony. as the earth moves in its orbit, the value of «# changes, so that its value in the spring, for instance, will be different from its value in the autumn. one pair of astronomers may attempt to synchronise a pair of clocks in the spring, but their synchronisa- tion will appear faulty to a second pair who repeat the deter- mination in the autumn. there will, so to speak, be one syn- chrony for the spring and another for the autumn, and neither pair of astronomers will be able to claim that their results are more accurate than those of their colleagues. more generally we may say that different conceptions of synchrony will corre- spond to different velocities of translation. these elementary considerations bring us to the heart of the problem which we illustrated diagrammatically in fig. 2. the observer at o in the diagram will have one conception of simul- taneity, while the second observer who moves from o to p will, on account of his different velocity, have a different conception of simultaneity. the instants at which the wave front of the light signal from o reaches the points a, b, c in the diagram will be deemed to be simultaneous by the observer who remains at o, but the observer who moves from o to p will quite un- consciously have different ideas as to simultaneity. at instants which he regards as simultaneous the wave front will have some form other than that of the sphere abc surrounding o. if the hypothesis of relativity is to be true in its application to the transmission of light signals, this wave front must be a sphere having p as its centre. einstein examined mathematically the conditions that this should be possible. a precise statement of his conclusions can only be given in mathematical language. the observer who is supposed to remain at o in fig. 2 may be supposed to make exact observations and to record these obser- vations in mathematical terms. to fix the positions of points in space he will map out a “ frame of reference” consisting of three orthogonal axes, and use cartesian co-ordinates x, y, z, to specify the projections along these axes of the radius from the origin to any given point. he will also use a time co-ordinate which may be supposed to specify the time which has lapsed since a given instant, as measured by a clock tn his possession. any observations he may make on the transmission of light sig- nals can be recorded in the form of equations betwecn the four co-ordinates x, y, 2, #. for instance, the circumstance that light travels from the origin with the same velocity ¢ in all directions will be expressed by the equation (of the wave front) :— vt y+te—cp=o (1) the second observer who moves from o to p will also construct a frame of reference, and we can simplify the problem by sup- posing that his axes are parallel to those already selected by the first observer. his co-ordinates, to distinguish them from those used by the first observer, may be denoted by the accented letters x’, y’, 2’, t’. if his observations also are to show light always to travel with the same velocity c in all directions, the equation of the wave front, as observed by him, must be:— x2 y'2 4 g!2— 67! =o (2) a roth-century mathematician would have insisted that x, y, z, i must be connected with x’, y’, 2’, ’’ by the simple relations: — x’ =x — ul ay! = it ef fis (a) f=] 327 but it is obvious that if these relations hold, then equation (1) cannot transform into equation (2). einstein finds that equa- tion (1) will transform into equation (2) provided the co-ordinates x, y, 2, £of the first observer are connected with the co-ordinates x’, y’, 2’, of the second observer by the equations:— x'= b (x—ut) y= (= (b) : xx f= a(t me: ee goa: where # stands for (-\",) : c* to form some idea of the physical meaning of these equations, it will be advantageous to consider the simple case in which the first observer is at rest in the aether while the second moves through the aether with velocity #. the points of difference between equations (b) and (a) then admit of simple explanation. the factor @ in the first of equations (b) is simply, according to the suggestion of fitzgerald and lorentz already mentioned, the factor according to which all lengths parallel to the axis of x must be adjusted on account of motion through the aether with velocity #. the moving observer must correct his lengths by this factor, and he must correct his times by the same factor in order that the velocity of propagation of light along the axis of x may still have the same velocity c; this explains the presence of the multiplier 6 in the last of equations (b). the one remain- ing difference between the two sets of equations, namely, the : ux, replacement of ¢ in (a) by ¢—~—; in (b), represents exactly the p want of synchrony which, as we have already seen, is to be expected in the observations of two observers whose velocity differs by a velocity a. although the equations admit of simple illustration by con- sidering the case in which one observer is at rest in a supposed aether, it will be understood that the equations are more gen- eral than the illustration. they are in no way concerned with the possibility of an observer being at rest in an aether, or in- deed the existence of an aether at all. their general interpre- tation is this: if one observer o, having any motion whatever, finds, as a matter of observation, that light for him travels uni- formly in all directions with a constant velocity c, then a second observer p, moving relative to o with a constant velocity # along the axis of x, will find, as a matter of observation, that light, for him also, travels uniformly in all directions with the same constant velocity c, provided he uses, for his observations, co-ordinates which are connected with the co-ordinates of o by equations (b). this is the meaning that was attached to the equations by einstein in 1905, but the equations had been familiar to mathe- maticians before this date. they had in fact been discovered by lorentz in 1895 as expressing the condition that all electro- magnetic phenomena, including of course the propagation of light, should be the same for an observer moving through the aether with velocity « as for an observer at rest in the aether. for this reason the transformation of co-ordinates specified by these equations is universally spoken of as a “ lorentz trans- formation.’’ what einstein introduced in 1905 was not a new system of equations but a new interpretation of old equations. the two observers who used the co-ordinates x, y,z,/and x’, y’,2’, t’ had been regarded by lorentz as being one at rest in an aether and one in motion with a velocity #; for einstein they were observers moving with any velocities whatever subject to their relative velocity being u. lorentz had regarded / as the true time and ?’ as an artificial time. if the observer could be per- suaded to measure time in this artificial way, setting his clocks wrong to begin with and then making them gain or lose perma- nently, the effect of his supposed artificiality would just counter- balance the effects of his motion through the aether. with einstein came the conception that both times, ¢ and ?’, had precisely equal rights to be regarded as true time. the measure 3.28 ft is precisely that which would be adopted naturally by any set of observers, or race of men, who disregarded their steady motion through space; their adoption of it would be above criticism if, as einstein suggested, their motion through space had no influence on material phenomena, and it represents, as we have seen, the usual practice of astronomers in comparing time at different places. from this point of view neither meas- ure of time is more accurate or more logical than the other. there are as many ways of measuring time as there are observers, and all are right. the investigator who is trying to discover laws of nature will, in general, require to measure cither directly or indirectly both time and space. if, to take a simple case, he is studying the motion of a single particle, he will measure out the position of the particle at definite instants as determined by his clock. he may specify the position of the particle at any instant by three measurements in space—for instance, he may say that two seconds after his particle started it was 6 ft. to the e. of the point from which it started, 9 ft. to the n. and 12 ft. vertically upward. the mathematician would express this by taking axes x, ¥,z to the e., to the n. and vertically upwards, and saying that at time /=2 the particle had co-ordinates x=6, y=9, 2=12. or he might, putting his time co-ordinate ¢ on the same footing as the space co-ordinates x, y, 2, simply say that x=6, y=9, 2= 12, /=2 represented one position of the particle. a complete set of readings of this type, each consisting of values of four co-ordinates, would give the complete history of the motion of the particle. such sets of simultaneous measurements form the common material of investigations in both pure and applied science. for instance, the engineer may measure the extension of a sample of steel corresponding to different loads; the electrician may measure the amount of light given by an electric filament corre- sponding to different amounts of current passed through it. in each of these cases there are only two quantities to be meas- ured simultaneously, and an investigator can conveniently represent the result of the whole series of his measurements in graphical form; a single reading is represented by a point whose distances from two fixed perpendicular lines represent the quan- tities measured, and the curve obtained by joining these single points will give all the information contained in the whole sct of readings. . we have seen that, in studying the motion of a particle in space, four sets of quantities must be measured, so that the results obtained cannot be plotted graphically on a piece of paper. their proper representation demands a four-dimensional space, in which x, y, 2 and # are taken as co-ordinates. the practical importance of such graphical representation is m7/, since it is impossible to construct a four-dimensional graph, but its’ thco- retical importance to the theory of relativity is immense. i’or if the hypothesis of relativity is true, then the four-dimensional graphs of any natural event constructed by all observers, no matter what their relative motions, will be identical. the in- fluence of their motion will be shown only in that the axes of x, y, 2 and ¢ will be different for different observers, and the relations between these sets of axes will be those given by the foregoing equations (b). the importance of this conception can hardly be overesti- mated, and it may be well to consider it further with the help of an illustrative example. imagine a number of aeroplanes flying over england, and, in order to eliminate one of the three direc- tions in space—the vertical—let us limit them to fly always at the same height, say 1,000 ft. above sea-level. imagine a number of similar plates of glass prepared, each marked faintly with an outline map of england and with lines of latitude and longitude. suppose that at 12 h.om. g.m.t. a plate is taken and the posi- tion of each aeroplane marked by a thick black dot. at 12 h. tm. let a second plate be taken and similarly marked, and let this be done every minute for an hour. ‘the 60 plates so marked will constitute a record of the motion of each aeroplane within this hour. if, now, we place the plates in order, one above the other, on a horizontal table, the mass of glass so formed will relativity present a graphical representation, in three dimensions, of the motions of all the aeroplanes. in this graph the two horizontal co-ordinates represent motions in any two rectangular directions over england, say ef. and n., while the third co-ordinate—the vertical—represents time. the individual black dots which represent the positions of any one aeroplane will form a dotted curve, and this curve gives a graphical representation of the motion of the particular aeroplane. our rectangle of glass con- tains the history, for one hour, of all the aeroplanes in graphical form. | to represent the motion of particles in the whole world of space a four-dimensional graph is required. the four-dimen- sional space in which it is constructed may, following the usual terminology, be spoken of as a four-dimensional continuum. the history of any particle in the universe—just as that of any aero- plane flying over england—will be represented by a continuous line in the continuum, and this is called the ‘‘ world line” of the particle. if the hypothesis of relativity is true the same continuum and the same world lines will represent the history of the particles of the universe equally well for all observers, the influence of their motions being shown only through their choosing different axes in the continuum for their axes of space and time. thus the continuum must be thought of as some- thing real and objective, but the choice of axes is subjective and will vary with the observer, the relation between different choices being expressed mathematically by our equations (b), the equations of the lorentz transformation. an inspection of these equations shows that the sets of axes chosen by different observers have different orientations in the continuum, so that what one observer describes as a pure space interval will appear to another to be a mixture of time and space. the instant of time and point in space at which any event occurs can be fixed by a single point in the continuum, so that the interval between two events will be represented by 4 finite line. the events and the interval between them are absolute, but the interval will be split up into time and space in different ways by different observers. the interval between any two events, such as the great fire of london and the outburst on the star nova persei, may be measured by one set of observers as so many years and so many millions of miles, but another set of observers may divide the interval quite differently. for in- stance a terrestrial astronomer may reckon that the outburst on nova perset occurred a century before the great fire of london, but an astronomer on the nova may reckon with equal accuracy that the great fire occurred a century before the outburst on the nova. a third astronomer may insist that the events were simultaneous. all will be equally right, although none will be right in an absolute sense. at this stage we may notice one respect in which our pile of glass plates failed to represent the true continuum. the mass of glass was stratified into different plates which represent different times for one particular observer. to obtain a section which would represent what an observer in motion relative to this first observer could regard as simul- taneous positions of the aeroplanes, we should have to cut the mass of glass on the slant. the continuum is more closely rep- resented by our plates of glassifthey are annealed into a solid mass from which all trace of the original stratification 1s made to disappear. all observers, no matter what their motion, are then equally free to cut a section to represent their individual ideas of simultaneity. thus space and time fade into subjective conceptions, just as subjective as right hand or left hand, front and behind, are in ordinary life. the continuum alone is objective and may be thought of as containing an objective record of the motion of every particle of the universe. the curve in which this record is embodied is spoken of as the world line of the particle in question. to use the words of minkowski: “ space in itself and time in itself sink to mere shadows, and only a kind of union of the two retains an independent existence,”’ gravitation and relativity.—since all the phenomena of light and of electromagnetism are believed, on almost incontrovertible evidence, to be in accordance with the hypothesis of relativity, relativity it is necessarily impossible to determine absolute velocity by optical or gravitational means. on the other hand, as we have already mentioned, the newtonian law of gravitation is readily seen to be inconsistent with the hypothesis of relativity. three alternatives are open:— (i.) the newtonian law may be true, in which case it must be possible to determine absolute velocity by gravitational means. (ii.) the newtonian law may be untrue in its original form, but may become true when amended so as to conform to the relativity hypothesis. gili.) neither of the foregoing possibilities mav be true. alternative (i.) was explored by sir oliver lodge, who, as- suming the exact truth of the newtonian law of gravitation, deduced that the observed motion of the perihelion of mercury could be accounted for if the sun were moving through space with a velocity of about 70 km. a second in a certain direction. this investigation had to be abandoned when it was shown by eddington that a similar discussion of the motions of the other planets would lead to vastly different values for the sun’s vel- ocity. alternative (ii.) was explored by einstein and others, but was found to lead to a motion of the perihelion of mercury equal only to one-sixth part of that actually observed. alternative (iii.) remained with its innumerable possibilities. einstein commenced his attack on the problem by eliminating all possibilities which did not conform to two general principles. the first of these was the principle of relativity. inasmuch as all physical phenomena except gravitation were believed to conform to this principle, it was natural to try, as a working hypothesis, the effect of assuming gravitation also to conform. the second principle was the so-called principle of equiva- lence, and this demands a word of explanation. to our children we explain that an apple falls to the ground because a force of gravitation inherent in the earth’s mass im- pels the apple towards the centre of the earth. most schoolboys know that this is not quite the whole story; the path of the apple is more accurately determined by supposing the apple to be acted on simultaneously by two forces—a gravitational force of attraction towards the earth’s centre and the centrifugal force arising from the earth’s rotation. it is only because the earth’s rotation is comparatively slow that the conception of an attraction towards the earth’s centre gives a tolerably plausible account of the fall of the apple. if the earth rotated at 17 times its present rate objects would not fall, even approximately, towards the earth’s centre; they would fall always parallel to the earth’s axis, and the inhabitants of the northern hemisphere might explain this as arising from a force of repulsion inherent in the pole star. if the earth rotated many times faster even than this, bodies would fall always perpendicularly away from the earth’s axis, and this might be interpreted as arising from a gravitational repulsion residing in the earth’s axis. these illustrations will show that it 1s easy to confuse accelera- tion arising from the earth’s rotation with gravitational attrac- tion. we may go further and say that it is impossible to dis- tinguish between the effects of gravitational attraction and the effects of acceleration of any kind whatever. every aeroplanist knows this to his sorrow; it is. inherently impossible to devise any instrument which shall show the direction of the vertical in an aeroplane, since an acceleration of the aeroplane produces on any instrument whatever, effects which are indistinguishable from those of gravity. from such considerations einstein was led to his principle of equivalence, which may be enunciated as follows:— a gravitational field of force at any point of space is in every way equivalent to an artificial field of force resulting from accelera- tion so that no experiment can possibly distinguish between them. guided by these two principles—relativity and equivalence— einstein was led to the view that all gravitational “ fields of force’ must be illusions. the apparent “ force ” arises solely from acceleration and there is no other kind of gravitational force at all. in this statement, as in the statement of the prin- ciple of equivalence above, the word acceleration is used in its 329 widest sense. acceleration results not only from change in the amount of a velocity, but from a change in its direction also. for instance a motor-cyclist riding in a circle at a uniform speed of 60 miles an hour will be the subject of an acceleration towards the centre of the circle. he knows that the apparent force so produced is just as real in its effects as gravitation, and to save himself from falling as a result of its influence he must incline the direction of his machine to the vertical. it is clear that the acceleration or curvature of path which figures as gravitation cannot be an acceleration or curvature in ordinary three-dimensional space. before the apple starts to fall from the tree there is neither acceleration nor curvature, and yet the apple is undoubtedly acted on by gravitation. moreover, this three-dimensional space is, as we have seen, different for different observers—it is a subjective and not an objective conception, and the gravitation resulting from such a curvature could not conform to the relativity condition. einstein was accordingly led to suppose that gravitation arose from curvature in the four-dimensional space, or continuum, in which time formed the fourth dimension. ‘this continuum, as has been seen, is objective and if the path of the particle can also be made objective, the resulting gravitation will conform to the relativity principle. the path of the particle in the continuum is, however, simply its “‘ world line,’ which we have already had under discussion. this world line is determined by natural laws, and if these are to be objective the specification of the world line must also be objective. there is, however, only one specification of world lines in the continuum which is objective in the sense that the same specification will give the same world lines to observers moving with different velocities. it is that every world line must be so drawn as to represent the shortest path between any two points on it. mathematically, jines which satisfy this condition are known as geodesics. thus einstein was led to suppose that world lines must be geodesics in the four-dimensional continuum. consider for a moment a page of this volume as presenting a two-dimensional analogy of the continuum. the shortest distance between any two points js of course the straight line joining them, so that the geodesics are simply straight lines. these possess no curvature of path, and if they formed a true analogy to the geodesics in the continuum there could clearly be no explanation of gravitation of the type we have been contemplating. there is, however, another type of two-dimen- sional surface. it is represented by the surface of a solid body such as a sphere—say the earth. on the earth's surface the geodesics are the great circles; every mariner or aeronaut who desires to sail the shortest course between two points sails along a great circle. to take a definite instance, the shortest course from panama to ceylon is not along the parallel of lat. (about 9° n.) which joins them—the aeronaut wishing to fly the shortest course between the two countries will fly n.e. from panama, he will pass over england and finally reach ceylon from the northwest. the reader may rapidly verify this by stretching a thread tightly over the surface of an ordinary geographical globe. let him now trace out the course on an ordinary mercator chart, and it will be found to appear very curved indeed—the course of the aeronaut will look surprisingly like that of a comet describing an orbit under the attraction of a sun situated somewhere near the middle of the sahara. the reader who performs these simple experiments will understand how einstein was led to suppose that gravitation could be explained by a curvature inherent in the continuum. the world lines of particles are geodesics but the space itself, so to speak, provides the curvature. the curvature of path is thrust upon the particle by the nature of the continuum, but we, who until recently have been unaware even of the existence of the continuum, have been tempted to ascribe it to the action of a special agency which we have invented ad foc and called ** gravitation.” according to einstein’s view of the nature of gravitation, it is no more accurate to say that the earth attracts the moon than to say that the pockets of an uneven billiard table repel the balls. y4 339 perhaps this train of thought may seem artificial. if so, the reason is that we have not been able to explore the other pos- sibilities which have branched off our main line of thought. in point of fact, einstein found himself practically limited to the conclusion we have stated. not only so, but the actual type and degree of curvature in the continuum prove to be uniquely fixed in terms of the masses of the gravitating bodies. thus einstein, knowing the mass of the sun, found himself in a position to predict absolutely what the motion of the perihelion of mercury ought to be. it was found to be 42-9” a century, a figure which agreed with observation to well within the limits of error of the observations. the motions of the other planets as predicted by the theory of relativity, have also been found to agree with those observed to within the errors of observation. this latter test is not a very stringent one, since the clepartures from the motion predicted by the newtonian law are too small to admit of very precise measurement. the effect of gravitation on light.—einstein’s theory requires that the world line of a ray of light also shall be a geodesic in the continuum. in a gravitational field the curvature of the contin- uum will impose a twist on the path of a ray of light. einstein found in particular that a ray of light which comes froma distant star and passes near the edge of the sun on its journey ought to be bent, in its passage past the sun, by an angle which should be 1-745\" if the ray just grazes the sun, and would be less, in proportion to the inverse distance from the centre of the sun, for other rays. . the observatories of greenwich and cambridge dispatched expeditions to test this prediction at the eclipse of to19. it was found that the stars which appeared near to the sun at the instant of eclipse showed an appreciable displacement, as com- pared with their normal positions, of the type required by ein- stein’s theory. exact measurement confirmed that the dis- placement varied approximately as the inverse <listance from the sun, and that the displacement at the limb was sensibly equal to einstein’s predicted value of 1-745”. the cambridge ob- servers, hampered by cloudy weather, obtained for this quantity the value 1:61” =0-30\". the greenwich observers obtained a value of 1:98”=0-12”, but prof. h. n. russell subsequently pointed out that their photographs indicate a horizontal and vertical scale difference of the order of one part in 12,000, almost certainly due to a distortion of the coelostat mirror under the sun’s rays, and if the measures are corrected for this the result is brought much closer to the theoretical prediction. three years later an expedition, sent out by lick observatory to observe the 1922 eclipse, was favoured by good weather and obtained for the displacement at the sun's limb, a value of 1-72” with a probable error of 0-11”. none of the expeditions had of course measured the deflections of stars actually at the sun's limb; most of the stars were several diameters away from the limb, the observed detlections being corrected so as to bring them to the limb. the dellections of stars at all distances were found to agree well with the predictions of einstein’s theory. the theory makes one further prediction which admits of experimental test. the atoms of any clement, say calclum, may be supposed to be formed according to a definite specification, the terms of which depend neither on the velocity of a particular observer nor on his position relative to the gravitational fields of the universe. it can be deduced that the light received from a calcium atom situated in the intense gravitational field near the sun’s surface ought to be of slower period, and therefore of redder colour, than the similar light emitted by terrestrial atoms. to be more precise, the fraunhofer lines in the solar spectrum ought to show a displacement to the red; this displacement ought to be homologous, and should be of amount 0-008 a units at the cyanogen band a 3883 at which observations have been chiefly made. attempts to test this prediction have led to strangely discordant results. all observers have found some effect of the kind predicted, but 1ts amount has generally been substantially less than the predicted amount, varying from almost sil (st. john, to17) to nearly the full amount to be expected (evershed, 1918 and 1923, grebe and bachem, rgrq). relativity the reason is that the predicted shift of 0-008 a is in any case hardly greater than the normal errors of observation and is apt to be masked by larger shifts of uncertain amount arising from other causes. larger shifts would be expected in stars which were of larger mass than the sun or of smaller radii. many known stars have masses far larger than the sun, but they also have larger radii, and so ought to showonly about the same spectral shift as the sun. on the other hand the class of stars known as “ white dwarfs ’’ have masses about equal to that of the sun, but far smaller radii. for instance calculation shows that the com- panion to sirius, a star whose radius is only about a thirty-fifth of that of our sun, ought to show a shift of as much as 0-30 a and when the matter was put to the test at mount wilson ob- servatory, w. s. adams found an actual shift of 0-32 a. it is hardly possible any longer to doubt that the spectral shift pre- dicted by einstein really exists. further developments.—it will have been seen that the re- stricted physical theory of relativity introduced a revolution into the foundations of scientific thought by destroying the objectivity of time and space. the gravitational theory has effected a hardly less important revolution by destroying our belief in the reality of gravitation as a “ force.”” the physicist has, however, to deal with other “‘ forces ” besides those of grav- itation, and the question inevitably arises as to whether these too must be regarded as illusions, arising only from our faulty interpretation of the special metrical properties of the con- tinuum. prof. h. weyl has pointed out that the continuum imagined by einstein and found to be adequate to explain gravitational phenomena, is not, in respect of its metrical properties, the most general type of continuum imaginable. a further generalisation is possible, and the new curvatures intro- duced must of necessity introduce new apparent forces other than gravitational. weyl’s investigation shows that these new forces would have exactly the properties of the electric and magnetic forces with which we are familiar. indeed, the pre- dicted forces coincide so completely with known electromagnetic forces that no experimental test of weyl’s theory is possible. hiad there been the slightest divergence between the forces predicted by weyl and those predicted by ordinary electro- magnetic theory, experiment could have been asked to decide between the two, but no such divergence exists. it may, how- ever, be said that wevl's theory makes it highly probable that all forces reduce to nothing more than our subjective interpreta- tions of special properties of the continuum in which we live. finally a thought may )e given to the position, under the new conceptions introduced by the theory of relativity, of the elec- tromagnetic aether. at one stage in the history of science there was a tendency to fill space with aethers, to the extent almost of one aether for every set of phenomena requiring explanation. that stage passed, and by the end of the roth century only one acther received serious consideration, the so-called electro- magnetic aether of faraday and maxwell. this acther gave a plausible mechanical explanation of electrostatic phenomena, although it was more than doubtful whether it could account for the electromagnetic phenomena from which it took its name, and it was comparatively certain that it could not account for gravi- tation. it gave, however, a satisfactory explanation of the propagation of waves of light—they were simply waves in the aether and travelled with an absolute velocity c determined once and for all by the structure of the aether. on this view it was quite certain that an observer moving through the aether with a velocity « would measure the velocity of light travelling in the same direction as himself as c=x#. relativity teaches that this velocity is always precisely c, and this in itself disposes of the aether of faraday and maxwell. whether any new aether will be devised to replace it remains to be seen, but none appears to be necessary. any aether which can be imagined would appear to depend upon an objective separation of time and _ space. relativity does not deny that such an objective separation may, in the last resort, really exist, but it shows that no material phenomena are concerned with such a separation. by a very slight turn of thought, the primary postulate of relativity may be relativity: philosophical consequences expressed in the form that the material world goes on as though no aether existed. to the relativist the essential background to the picture of the universe is not the varying agitation of a sea of aether in a three-dimensional space but a tangle of world-lines in a four- dimensional space. moreover, it is only the intersection of the world lines that are important. an intersection at a point in the continuum represents an event, while the part of a world line which is free from intersections represents the mere uneventful existence of a particle or a pulse of light. and so, since our whole knowledge of the universe is made up of events, it comes about that the tangle of world lines may be distorted and bent to any degree we please; so long as the order of the intersections is not altered, it will still represent the same universe. and so the last function of the aether, that of providing a scale of absolute measurements in space, becomes a superfluity. to the physicist who urges that space measurements without an underlying aether become meaningless, the relativist can reply that time- measurements without an underlying “ time-aether’’ are equally meaningless. a “ time-aether ” has never been regarded as a necessity, and the relativist feels that the ‘‘ space-aether ” has no greater claim to retention. brsltiocraphy.—a. s. eddington, space, time and gravitation (1921); the afathematical theory of relativity (1924); a. einstein the meaning of relativity (1922); viscount haldane, the reign of relativity (1921); t. p. nunn, relatinty and gravitation (1923); bertrand russell, a. b. c. of relativity (1925); 11. weyl, space, time and matter (1922); a. n. whitehead, yhe principle of relativity (1922). (j. h. je.) relativity: philosophical consequences.—of the consequences in philosophy which may be supposed to follow from the theory of relativity (g.v.), some are fairly certain, while others are open to question. there has been a tendency, not un- common in the case of a new scientific theory, for every philos- opher to interpret the work of einstein in accordance with his own metaphysical system, and to suggest that the outcome is a great accession of strength to the views which the philosopher in question previously held. ‘this cannot be true in all cases; and it may be hoped that it is true in none. it would be dis- appointing if so fundamental a change as einstein has introduced involved no philosophical novelty. (see space-time.) space-time.—for philosophy, the most important novelty was present already in the special theory of relativity; that 1s, the substitution of space-time for space and time. in newtonian dynamics, two events were separated by two kinds of interval, one being distance in space, che other lapse of time. as soon as it was realised that all motion is relative (which happened long before einstein), distance in space became ambiguous except in the case of simulfaneous events, but it was still thought that there was no ambiguity about simultaneity in different places. the special theory of relativity showed, by experimental argu- ments which were new, and by logical arguments which could have been discovered any time after it became known that light travels with a finite velocity, that simultaneity is only definite when it applies to cvents in the same place, and becomes more and more ambiguous as the events are more widely removed from each other in space. this statement is not quite correct, since it still uses the notion of ‘‘ space.”” the correct statement is this: events have a four- dimensional order, by means of which we can say that an event a is nearer to an event b than to an event c; this is a purely ordinal matter, not involving anything quantitative. but, in addition, there is between neighbouring events a quantitative relation called ‘ interval,” which fulfils the functions both of distance in space and of lapse of time in the traditional dynamics, but fulfils them with a difference. if a body can move so as to be present at both events, the interval is time-like. if a ray of light can move so as to be present at both events, the interval is zero. if neither can happen, the interval is space-like. when we speak of a body being present “‘ at ” an event, we mean that the event occurs in the same place in space-time as one of the events which make up the history of the body; and when we say that two 331 events occur at the same place in space-time, we mean that there is no event between them in the four-dimensional space-time order. all the events which happen to a man at a given moment (in his own time) are, in this sense, in one place; for example, if we hear a noise and see a colour simultaneously, our two percep- tions are both in one place in space-time. when one body can be present at two events which are not in one place in space-time, the time-order of the two events is not ambiguous, though the magnitude of the time-interval will be different in different systems of measurement. but whenever the interval between two events is space-like, their time-order will be different in different equally legitimate systems of measure- ment; in this case, therefore, the time-order does not represent a physical fact. it follows that, when two bodies are in relative motion, like the sun and a planet, there is no such physical fact as * the distance between the bodies at a given time ”’; this alone shows that newton’s law of gravitation is logically faulty. fortunately, einstein has not only pointed out the defect, but remedied it. his arguments against newton, however, would have remained valid even if his own law of gravitation had not proved right. time not a single cosmic order. —the fact that time is private to each body, not a single cosmic order, involves changes in the notions of substance and cause, and suggests the substitution of a series of events for a substance with changing states. the con- troversy about the acther thus becomes rather unreal. un- doubtedly, when light-waves travel, events occur, and it used to be thought that these events must be “in” something; the something in which they were was called the aether. but there seems no reason except a logical prejudice to suppose that the events are “in”? anything. matter, also, may be reduced to a law according to which events succeed each other and spread out from centres; but here we enter upon more speculative con- siderations, 2 physical laws.—prof. eddington has emphasised an aspect of relativity theory which is of great philosophical importance, but difficult to make clear without somewhat abstruse mathe- matics. the aspect in question is the reduction of what used to be regarded as physical jaws to the status of truisms or defini- tions. prof. eddington, in a profoundly interesting essay on “the domain of physical scitence,”? states the matter as follows :— in the present stage of science the laws of physics appear to be divisible into three classes—the identical, the statistical and the transcendental. the “ identical laws '’ include the great field-laws which are commonly quoted as typical instances of natural law— the law of gravitation, the law of conservation of mass and energy, the laws of electric and magnetic force and the conservation of elec- tric charge. ‘these are seen to be identities, when we refer to the cycle so as to understand the constitution of the entities obeying them; and unless we have misunderstood this constitution, violation of these laws is inconceivable. ‘they do not in any way limit the actual basal structure of the world, and are not laws of governance (op. ctt., pp. 214-5). it is these identical laws that form the subject-matter of relativity theory; the other laws of physics, the statistical and transcendental, lie outside its scope. thus the net result of rel- ativity theory is to show that the traditional laws of physics, rightly understood, tell us almost nothing about the course of nature, being rather of the nature of logical truisms. this surprising result is an outcome of increased mathemat- ical skill. as the same author? says elsewhere:— _in one sense deductive theory is the enemy of experimental! physics, lhe latter is always striving to settle by crucial tests the nature of the fundamental things; the former strives to minimise the successes obtained by showing how wide a nature of things is compatible with all experimental results. . the suggestion is that, in almost any conceivable world, something will be conserved; mathematics gives us the means of constructing a variety of mathematical expressions having this property of conservation. it is natural to suppose that it is useful 1 in sctence, religion and reality, ed. by joseph needham (1925), 2a. 5s. eddington, mathematical theory of relativity, p. 238 (cambridge, 1924). 332 to have senses which notice these conserved entities; hence mass, energy, and so on seem to have a basis in our experience, but are in fact merely certain quantities which are conserved and which we are adapted for noticing. if this view is correct, physics tells us much less about the real world than was formerly supposed. force and gravitation.—an important aspect of relativity is the elimination of “ force.” this is not new in idea; indeed, it was already accepted in rational dynamics. but there remained the outstanding difficulty of gravitation, which einstein has over- come. the sun is, so to speak, at the summit of a hill, and the planets are on the slopes. they move as they do because of the slope where they are, not because of some mystcrious in- fluence emanating from the summit. bodies move as they do because that is the easiest possible movement in the region of space-time in which they find themselves, not because “ forces ” operate upon them. the apparent need of forces to account for observed motions arises from mistaken insistence upon euclidean geometry; when once we have overcome this prejudice, we find that observed motions, instead of showing the presence of forces, show the nature of the geometry applicable to the region con- cerned. bodies thus become far more independent of each other than they were in newtonian physics: there is an increase of individualism and a diminution of central government, if one may be permitted such metaphorical language. this may, in time, considerably modify the ordinary educated man’s picture of the universe, possibly with far-reaching results. realism in relativity—it is amistake to suppose that rela- tivity adopts an idealistic picture of the world—using “ ideal- ism ”’ in the technical sense, in which it implies that there can be nothing which is not experience. the “ observer” who is often mentioned in expositions of relativity need not be a mind, but may be a photographic plate or any:kind of recording in- strument. the fundamental assumption of relativity is realistic, namely, that those respects in which all observers agree when they record a given phenomenon may be regarded as objective, and not as contributed by the observers. this assumption is made by common sense. the apparent sizes and shapes of ob- jects differ according to the point of view, but common sense discounts these differences. relativity theory merely extends this process. by taking into account not only human observers, who all share the motion of the earth, but also possible “ ob- servers ” in very rapid motion relatively to the earth, it 1s found that much more depends upon the point of view of the observer than was formerly thought. but there is found to be a residue which is not so dependent; this is the part which can be ex- pressed by the method of ‘ tensors.”” the importance of this method can hardly be exaggerated; it is, however, quite impossi- ble to explain it in non-mathematical terms. | relativity physics —relativity physics is, of course, concerned only with the quantitative aspects of the world. the picture which it suggests is somewhat as follows:—in the four-dimen- sional space-time frarne there are events everywhere, usually many events in a single place in space-time. the abstract mathematical relations of these events proceed according to the laws of physics, but the intrinsic nature of the events is wholly and inevitably unknown except when they occur in a region where there is the sort of structure we call a brain. then they become the familiar sights and sounds and so on of our daily life. we know what it is like to see a star, but we do not know the nature of the events which constitute the ray of light that travels from the star to our eye. and the space-time frame itself 1s known only in its abstract mathematical properties; there is no reason to suppose it similar in intrinsic character to the spatial and temporal relations of our perceptions as known in experience. there does not seem any possible way of overcoming this ignorance, since the very nature of physical reasoning allows only the most abstract inferences, and only the most abstract properties of our perceptions can be regarded as having objective validity. whether any other science than physics can tell us more, does not fall within the scope of the present article. meanwhile, it is a curious fact that this meagre kind of knowledge is sufficient for the practicud uses of physics. from a relief work practical point of view, the physical world only matters in so far as it affects us, and the intrinsic nature of what goes on in our absence is irrelevant, provided we can predict the effects upon ourselves. this we can do, just as a person can use a telephone without understanding electricity. only the most abstract knowledge is required for practical manipulation of matter. but there is a grave danger when this habit of manipulation based upon mathematical laws is carried over into our dealings with human beings, since they, unlike the telephone wire, are capable of happiness and misery, desire and aversion. it would therefore be unfortunate if the habits of mind which are appropriate and right in dealing with material mechanisms were allowed to dominate the administrator’s attempts at social constructiveness. bibliography.—a. s. eddington, space, time, and gravitation (cambridge, 1921); bertrand a. w. russell, zhe a. b. c. of rela- tivity (1925). (b. a. w. r.) relief work.—upon the outbreak of the world war in 1914 relief problems far surpassed the capabilities of private charity, involving broad questions of governmental finance, control of production, purchase and transport of huge quantities of supplies from one part of the world to another, intervention of diplomatic agencies, control of shipping and railways, and finally, after the war, general economic rehabilitation and broadly con- ceived treatment of fundamental social ills. for the first time in history, virtual world control of production and distribution of food was attained (see rep cross). civitian relief in belgium and france during the occupation of belgium inhabitants found them- selves in desperate straits from the interruption of agriculture and the confiscation of stocks by the occupying forces. belgium’s essential food imports were cut off, and hordes of refugees fled before the advancing german armies. a belgian committee was formed and appealed for aid. herbert hoover, an american engineer, recognised the urgency of the situation, and with the backing of the u.s. govt. persuaded the allied govts. to open the blockade and to secure proper guarantees from germany against interference and requisitioning of local food products that would otherwise have to be imported. the commission for relief in belgium (c.r.b.) established by herbert hoover as a neutral organisation in the midst of war, possessing recognised diplomatic rights and obligations, flying its own flag and issuing iis own passports, held an unprecedented status. the commission faced not only large problems of transporta- tion, blockade and distribution, but the marshalling of hundreds of millions of dollars to supply food to the 9,000,c00 inhabitants of belgium and northern france. food had to be secured in dis- organised markets, supplies had to pass across mine-strewn north sea waters through the naval blockade, be transhipped to barges and towed through 133 m. of obstructed waterways, passing across the german military line. the first relief cargo of 2,300 tons of food reached brussels on nov. 1 1914. it led a procession of relief vessels, 2,313 in number, carrying in the neigh- bourhood of 100,000 tons each month for nearly five years. the harvest of 1914, at the time of the invasion, was uncon- trolled; but in addition to many other diplomatic guarantees exacted from both germany and the allies, the commission formed a committee of germans, belgians and americans which took over subsequent harvests of breadstuffs, insuring equitable distribution to the civil population. the world’s charity was mobilised through nearly 2,000 committees located in the united states, great britain, canada, australia, new zealand, india, south africa, holland, italy, spain, argentina and elsewhere. within belgium and northern france were set up nearly 10,000 communal committees dealing with food supplies. purchasing and shipping agencies were organised in the principal world markets and ports. offices for governmental liaison were main- tained at brussels, london, paris and washington. upon ameri- ca’s entry into the war the c.r.b. remained unchanged, except for the necessary withdrawal of american directors from within the german lines. the spanish-dutch committee for the pro- tection of the relicf in belgium and northern france was formed, relief work and took over diplomatic and other functions within the lines. the national committees, one belgian and one french, for diplo- matic reasons necessarily under control of the c.r.b., admin- istered distribution. these were the belgian comite national de secours et d’alimentation and the comite d’alimentation du nord de la france under the leadership of emile francqui. during the whole period of relief the commission acquired goods well over $1,300,000,000 in value, including interchange of native products. more than 55,000 volunteers gave their serv- ices. over 5,000,000 tons of supplics were imported. foods were acquired by purchase abroad with gift money, from gifts in kind, by purchase from commercial exchange out of belgium, and by purchase with governmental subsidies. the belgian govt. granted monthly fixed subsidies to the commission from loans advanced by the united states, great britain and france. the actual financial resources of the commission amounted to $894,797,150, the expenditure of the benevolent side of the relief organisation was $615,237,147 of this total. of the total funds available to the commission, 47° came from the united states ($421,153,287); 23° from french treasury loans ($204,862,854); 14% from british empire sources ($125,686,364); and 16° from other sources. the total administrative expenditure of the c.r.b. was kept down to less than one-half of one per cent. the average prices maintained for staple foods in the occupied terri- tory during the entire period of the war were from 15 to 20% less than prices in the allied countries at the same periods. with the signature of the armistice the programme increased to revive the weakened population, and the belgian and french govts. in may 1019, took the responsibility of feeding their people. relief in central europe when peace came in nov. 10918 the allied and associated govts. were confronted with the necessity of extending relief not only to liberated territories in central europe but also to their enemies. from the baltic to the adriatic and black seas hun- dreds of millions of people needed food to save them from an even greater catastrophe that would follow if they were allowed to starve before agricultural production could be brought back and before industries and transportation could be restarted. werbert hoover was appointed director-general of allied relief, acting under the supreme economic council. because america found itself in a better food position than any of the nations of europe, the united states was destined to play the principal part, supplemented by a substantial programme of great britain. mr. hoover formed the american relief administration (a.r.a.) to carry out the work, placing financial, purchasing and shipping problems in charge of the u.s. grain corporation. to assure the success of the complicated arrangements for the mass feeding of millions of people the director-general assumed temporary control of railways in central and southern europe, re-established or controlled 10,000 m. of telegraph and telephone lines, arranged barge shipments on european rivers, initiated food exchanges between the newly established states, re-allocated army supplies suitable for civilian needs, established a temporary monetary exchange system, furthered the import of raw material, controlled coal production and in general helped struggling governments to re-establish normal economic life. food from america had to be transported overseas and dis- tributed in 21 countries or states, including allied, neutral, ex- enemy and the smaller new states. american deliveries to allied or neutral countries were financed on credit by the u.s. treasury. with the exception of austria, deliveries to ex-enemy countries were paid for in cash. deliveries to the new states were either outright gifts or long-term loans without considering ability to repay. in addition to u.s. credits and other resources, the u.s. congress appropriated $100,000,000 as a revolving fund for the operations. ex-enemy countries were excluded from benefits from this fund. allied and neutral countries supplied by the united states were italy, denmark and holland; ex-enemy countries supplied against cash payments were germany, aus- tria, hungary, bulgaria and turkey. the so-called liberated territories supplied were finland, estonia, northwest russia, 333 latvia, lithuania, poland, belgium, northern france, czecho- slovakia, rumania, yugoslavia, south russia and armenia. great britain’s part in these measures was large. notwith- standing its difficult financial position, the british govt. was able to appropriate {12,500,000 and to set up other substantial grants. great britain agreed to fill the gaps between what the united states could provide and what was required for barest necessitics in war-torn regions. british assistance was given to poland, serbia, czechoslovakia, rumania, estonia and austria. the british relief was administered by sir william goode. during the armistice year relief deliveries to europe reached about 4,760,c00 tons of food valued at over $1,147,600,000. more than two-thirds of the programme, or $870,000,000 worth, came from the united states. about $120,000,000, or 10%, came from the united kingdom; from france and italy about 2% each; about 4° was financed jointly by the united states, france and italy; and about 5°, came from other countries. of the us. deliveries 1 in 1919 about 20°% were sold for cash, 77% on credit and 2-2% ($19,300,000) as charity. of the british deliv- eries 65 °% were ald for cash, 32% on credit and 3% ($3,500,000) as charity. operations were supervised largely by army and navy officers, whose services were lent by their governments. inland transportation was paid for by the governments aided. local ministries and native volunteer committees attended to distribution. these prompt relief measures undoubtedly saved europe from an even greater social cataclysm than her people had al- ready suffered. weakened by war, without food or employment, eastern europe provided a breeding ground for anarchy and social revolution of the brand that had already laid russia in economic ruin. russian emissaries of world proletarian revolu- tion actively spread through the small new states whose govern- ments were inexperienced, tossed in political turmoil and in fervid chauvinistic conflict with surrounding neighbours. the relief operation laid down “a wall of food” against militant russian bolshevism, in fortifying the people for resumption of the production without which they could not live. they helped to bring order out of chaos to the end that factories could start and transportation be resumed. privately organised relief —with the signing of peace, all these allied and american organisations passed out of existence. certain stocks given by the american govt. for charitable pur- poses were turned over to a new private organisation formed by herbert hoover, also known as the american relief administra- tion. large numbers were still faced by extreme shortage. children were the greatest sufferers. the new privately organ- ised a.r.a. carried on mass child feeding in finland, estonia, latvia, lithuania, danzig, poland, northern france, czecho- slovakia, austria, hungary, rumania, yugoslavia and armenia. american quakers co-operated with the a.r.a. in feeding over 1,000,000 children in germany. with gradual reductions, as were permitted by economic recovery, the work was carried on until 1923. during the whole of that period about 8,000,000 different chil- dren benefited from these charitable relief importations. free cooked meals were distributed to as many as 4,000,000 children daily at one time, to whom a total of over 1,500 million meals were served. warm clothing to the value of over $8,000,000 was distributed to more than 2,000,000 children. each of the coun- trics aided assumed the burden of transportation and storage within their country and assisted in distribution. these govern- ments also donated some foods and financed some of the foreign importations. over 1r00,0co men and women co-operated in this preservation of the coming gencration from war’s ravages. their ready response demonstrated the effectiveness of a foreign aid specifically organised to help the people of these new states to help themselves, rather than to dispense a charity which merely maintained an individual or group without offering aid and in- centive to self-help. national welfare bodies thus founded and built up by the a.r.a. were perpetuated in many countries. the total amount expended for these post-war charitable operations reached nearly $100,000,000. 334 prisoners of war.—dr. fridtjof nansen prevailed upon the newly formed league of nations to help in repatriation of pris- oners of war, bringing more than 427,000 war prisoners out of russia and siberia back to their homes in a dozen countries. prominent in post-war relief works were the save the children funds of great britain and many other countries which, through dr. nansen, brought help to eastern european countries; the american jewish joint distribution committee in poland, czechoslovakia, austria and other places; several irish relief committees; the american and british societies of friends (quakers). the french war orphans committee brought aid to children in devastated france. the rockefeller foundation gave over $22,500,000 for the relief work of the commission for relief in belgium and other charitable purposes. russian famine-—when these post-war relief operations were closing down, famine in russia brought 25,000,000 people in the volga valley face to face with starvation. herbert hoover revived the american relief administration, secured grants from the u.s. govt., induced the soviet russian govt. to pur- chase seed grains, and rushed food, grain and medical supplies to the stricken country. because of dilapidated ports, broken- down railways, the general inertia of the broken morale of the russian people, and the dissolution of the productive organism, complicated by suspicions of the so-called proletarian soviet govt. against emissaries from “ capitalistic ” america, the task of bringing immediate and effective relief to the people in an area of 770,000 sq. mm. was immense. it was necessary to initiate and supervise every step of operations of transport and distribu- tion amid greatest economic disruption and appalling scenes of misery. . the administration of this relief was accomplished by less than 200 persons supervising a distributing organisation of nearly 150,000 russian workers. more than 10,000,000 people were fed; medical and sanitary supplies valued at $7,600,000 were distributed to 16,500 hospitals and other institutions to combat the spread of typhus, cholera, and other epidemics following in the wake of famine; over 8,000,000 vaccinations or inoculations against smallpox, typhoid and para-typhoid were given to people in epidemic regions; 200,000 tons of seed grain were distributed; and other relief measures brought the total value of american relief to the russian famine to about $60,000,000. the work was made possible by the contribution of $24,000,000 in cash and medical supplies by the u.s. govt., of $3,600,000 worth of medical supplies by the american red cross, about $4,000,000 by the american joint distribution committee, and of $12,000,000 worth of seed grain purchased and transported by the a.r.a. against gold payment by the soviet government. many other american groups co-operated with mr. hoover in furnishing means to an extent of nearly $3,000,000. these were the society ar friends, mennonite relief, european student relief, federal council of churches of christ in america, knights of columbus, national catholic welfare council, national lutheran council, volga relief society, y.m.c.a. and y.w.c.a. the russian opera- tions of the american relief administration started in sept. 1921, and were brought to a close in july 1923. although the sums thrown into russian famine relief by british agencies and the nansen relief committee were small in comparison with the american relief, the accomplishment was effective. as high commissioner for the league of nations, dr. nansen also co-operated with the a.r.a. in care of russian refugees in the balkans, arranging for the transport of some 15,000 of these refugees to other localities where they could be supported. (see rockefeller foundation.) bibliography.—annual reports and bulletins of the a.r.a. and the other relief associations mentioned in the course of the article; sidney brooks, america and germany, 1918-25 (new york, 1925), and america and poland, 1915-25; wh. h. fisher, american relief administration in the russian famine (new york, 1926); c.s. young, clara barton (new york, 1923); g. i. gay, the com- mission for relief in belgium, stanford university, cal.; sir william goode, economic conditions in central europe (cmd. 641, london, 1920). (g. b. b.*) remizov, alexis (1877- ), russian novelist, was born june 24 1877 in moscow and brought up amid factory surround- ings and in the strict observance of orthodox church rites, with frequent pilgrimages to monasteries. he thus gained an inti- mate knowledge of national habits, monastic life and old reli- gious legends. he studied natural science and economics at moscow university, took part in revolutionary activities, and was imprisoned and spent years of exile in wologda. he sub- sequently went to live in paris. the influences of his varying remizov—renner surroundings contributed to the formation of his unique fan- tastic personality uniting the whimsical mischievousness of some fairy-tale sprite with a deep spirit of pity. his literary life dates from 1902; from that time until 1920 he published 36 volumes of fiction: novels, tales, short stories and fairy-tales, miracle plays, etc. the most remarkable of remizov’s novels are the pon (1905), a powerful and gloomy picture of vulgarity, vice and crime among the moscow bourgeoisie and the monasteries. the clock (1908, eng. trans. 1924), the fifth pestilence, novels of provincial life; the sisters of the cross (1910), a novel of st. petersburg life; also the cockerel and stories relating to the revolution of 1905, and several miracle and folk plays. a great realist, remizov has perhaps exercised more influence than anyone else of his generation upon contemporary russian fiction. renevier, eugene (1831-1906), swiss geologist (see 23.98), died at lausanne may 4 1906. renner, karl (1870— ), austrian politician, was born on dec. 14 1870, the son of a peasant, at dolni-dunajovice, moravia. he studied law at the university of vienna, and early attached himself to the social democratic party. he became an official in the library of the reichsrat, and under the pseudo- nyms of “ synopticus ”’ and “‘ rudolf springer ” showed a fer- tile literary activity, especially in connection with the problems of the austrian state, whose existence he justified on geographi- cal, economic and political grounds. on the nationality question he upheld the so-called ‘‘ personal autonomy,” on the basis of which the super-national state should develop, and thereby influenced the programme and tactics of the social democratic party in dealing with it. as a theorist he was reckoned as one of the leaders of neo-marxism. he had been a deputy since 1907, and, as leader of the social democrat party, he repeatedly attacked the government. he deeply influenced the movement which preceded the fall of the monarchy. after the collapse he became head of the government, and after the elections had given the social democrats and christian socialists an over- whelming majority, he formed a coalition ministry, as the leader of which he became the first chancellor of the austrian republic. renner was largely responsible for the decrees of the national assembly which called for the dethronement of the dynasty of habsburg-lorraine and the banishment of all members of this house if they did not submit entirely to the laws of the republic, and he was in charge of the negotiations which led to the ex- emperor charles leaving austria in march 1919. he was responsible for thwarting the separatist endeavours of the dif- ferent provinces and the demands which the communists, sup- ported by their partisans in foreign countries, made with the object of overthrowing the government. on may 12 1919, he went to paris as head of the austrian delegation to receive the conditions of peace from the victors. on his return consulta- tions were held whether to accept or to refuse the conditions of peace. otto bauer, who at that time was secretary for foreign affairs, refused to take responsibility for certain provisions of the treaty, and resigned. renner now took over the conduct of foreign affairs and signed the treaty of st. germaine-en-laye of sept. 10 r919. it was accepted by the national assembly in oct. r919, and came into force in july 1920. in dec. 1919 renner went to paris to depict austria’s miserable situation to his former enemies and to beg for help. his efforts were not without success. a special austrian section of the reparations commission was appointed to study the measures necessary for a lasting cure for the ills of the body politic and gradually brought help. it is true that the republic grew more and more de- pendent on the powers signatory to the treaty of st. germain, in consequence of the interference of the various inter-allied commissions which had to supervise the disarming of austria by land, sea and air. meanwhile, the first coalition ministry had been succeeded in oct. 1919 by a second, in which renner was again chancellor and secretary for foreign affairs. his endeavours were now directed towards establishing better relations with the succession states. the journeys which he undertook to this end to rome renoir—reparations and the dawes plan and prague were not unsuccessful and paved the way to further negotiations. on the other hand, the relations between the austrian government and hungary, which since the regime of the revolution had been succeeded by a reaction, were very strained. renner, who, as a social democrat, had been inimical to the reactionary hungarian government and feared that an accession of strength to it would bring danger to the austrian republic, refused the hungarian government the assistance which it asked in its struggle with the leaders of the soviet party, who had fled to vienna. this brought him into conflict with the christian socialists and their representatives in the cabinet. the coalition broke up in june; but renner remained in charge of foreign affairs in the so-called “ proportional cabinet,”” only resigning in oct. 1920. he continued to take part in the parliamentary debates and the enterprises of the social democrat party. but his influence rapidly declined. _ his principal works are grundlagen und entwicklungsziele der osterreichisch-ungarischen monarchie (1906); oesterreichs erneuerung (1919); die wirtschaft als gesamtprosess und die sosialisierung (1924), (a. f, pr.) renoir, auguste (1841-10919), french painter (see 23.101), died at cagnes, france, dec. 3 1910. reparations and the dawes plan.—the treaty of versailles in june 191g did not directly settle or deal with the question of reparations in its financial aspects. it placed on germany the moral responsibility for all damage done to the population of the allied countries (see versailles, treaty of). it set up a reparation commission to translate the treaty into actual figures by assessing the damage, to lay down the method and times of payment, and to come to its determination by may 1921. i. from the treaty to the london conference san remo to spa.—in april and may 10920 the allies (great britain, belgium, france, italy and japan) met in conferences at san remo and hythe, and discussed in a preliminary way the methods of computing the liability of the enemy countries and also of sharing the proceeds. the supreme council had their own experts making computations, the reparation com- mission in the meantime continuing their investigation of the damages and mode of collection. (at this stage there was a tentative agreement for france to pay her debt as and when she received payment from germany.) in june 1920 at boulogne, statements of actual amounts emerged. a minimum annuity of 3,000 million gold marks for 35 years, with a maximum agegre- gate of 269,000 million,was proposed; the actual amount to be. settled by economic conditions. the costs of military occu- pation were to be a first charge on the “ deliveries in kind,” of which coal was the chief, and customs and natural resources were to be employed as guarantees. at the important spa conference—july ro20 (following a meeting of experts at brussels) and with germany and portugal represented, they dis- cussed proposals for germany to pay 42 annuities aggregating 240,000 million gold marks; coal deliveries were fixed at two million tons monthly forthwith. there was ‘an actual agree- ment, which has survived, as to the division of the proceeds as follows: — /o /0 france $s & x x “s2 belonim... ...-. < “8 british empire : . 22 japan and portugal 1-50 italy...) .)~) sco 10s others (greece, rumania, tc} a ce okso a priority for 2,c00 million gold marks was given to belgium. at this conference the germans expressed their views on the importance of territorial integrity, and the necessity for first securing an “‘ export surplus ” before making any payment in cash or kind. the paris decistons.—in dec. 1920 financial experts met in brussels and made recommendations to the supreme council, and on jan. 29 1921 the allies reached the ‘ paris decisions.” the fixed annuities were to be:— 330 (a) 2 annuitics of 2 milliard gold marks. (6) 3 annuities of 3 milliard gold marks. (c) 3 annuities of 4 milliard gold marks. (d) 3 annuities of 5 milliard gold marks reached by may 1932. (e) 31 annuities of 6 milliard gold marks reached by may 1963. these 42 annuities were to be paid from 1921 equal to 12% of the value of germany’s exports. supervision of customs and occupation of the ruhr in event of failure were discussed. in feb. 1921 the various allies had submitted their “claim” to the reparation commission, for damages alone the claims totalled about roo milliard gold marks (1 milliard gold marks=s5o0 million sterling) but including other claims the total was about 225 milliard gold marks, or, say, 11,600 million sterling. in march 1921 at the first london conference, germany proposed 1,500 million pounds in cash over 30 years, with credit for 1,000 millions already paid. in april through the united states a vastly increased offer was made with stipulations about the return of surrendered territory. ii. from the london conference to the dawes committee the london ultimatum.—on april 27 1921, the reparation commission announced their ‘‘ assessment’ as 132 milliard gold marks (6,600 million sterling, or 58° of the claim). the decision did not refer to germany’s “ capacity to pay ” at all— it was a computation of legal liability, on the terms of the treaty. ‘the allies decided that this was to be paid in annuities of £100,000,000, plus 26% of german exports. three series of bonds were to be issued, two in 1921, (a) 600 million pounds, (6) 1,900 million, and the balance as series (c) 4,100 million at such time as the reparation commission might determine. these bonds were to bear 5% interest, and 1°% amortisation. upon this report the london conference issued an ultimatum (may § 1921), giving effect to those decisions and also deciding that deliveries of coal and materials, etc., were to continue, germany being given credit for the appropriate values. a committee of guarantees was to be set up to report upon the german fiscal revenues and to supervise the actual machinery for delivering funds, etc. occupation of the ruhr valley and penalties in regard to customs and other revenues were proposed in case germany failed to accept the terms. the first payment of one milliard gold marks due by sept. 1 1921 was actually paid over, partly out of foreign balances which had accumulated prior to may, partly by sales of paper marks on the exchange, and partly by temporary advances from an international group of banks. deliveries in kind after may covered the nov. instalment. the export tax, a quarter of a milliard, was paid for the first quarter. in oct. certain details were agreed between the french and german ministers at wiesbaden in regard to deliveries in kind for france, in place of the 26% export tax, and the practical details of these agreements were subsequently accepted by the other governments concerned. difficulties began to arise almost immediately in regard to the payment of the annuities. in aug. 1921, mr. j. m. keynes first published his famous prediction that the instalments of jan. and feb. 1922 might be covered out of further ‘‘ deliveries,’”’ tem- porary advances and foreign assets of german industrialists. but the payment of april 1922 would present more difficulty. “ some- time between feb. and aug. 1922 germany will succumb to an inevitable default. this is the maximum extent of our breath- ing space.”’ in dec. 1921 the german government notified the reparation commission that their attempt to raise a foreign loan having been abortive, they could not raise in addition to deliveries in kind more than 200 million gold marks on account of the payments for jan. and feb. 1922. there were con- ferences of the allied prime ministers at london in dec. 1921 and cannes in jan. 1922, as a result of which the commission granted a moratorium to germany from the amounts due under the schedule of payments, accepting payments of 31 million gold marks every 10 days. it was laid down that germany was to present plans for balancing the budget, stabilising the 336 currency and preventing exports of capital. shortly after, germany made an offer of 720 million gold marks per annum in addition to 1,450 million by deliveries in kind, agreeing to balance the budget, increase the coal and sales tax and check inflation by a compulsory loan. germany asked for a reduction of the treaty payments to an amount within her capacity. at the paris conference in march (march 11 1922) the rep- aration commission were asked to consider the possibility of an external loan, but an international committee of bankers, which met at the end of may, concluded that sucha loan was impossible so long as germany’s external liabilities remained at the figure arranged. meanwhile in march 1922 the reparation commission agreed to a payment of 720 million gold marks inclusive, as the cash payment, suspending the schedule of pay- ments in the meantime, and laying down that germany should impose her new taxation at once or be exposed to the ‘‘ sanc- tions ’’ of the london agreement. in aug. 1922, after germany had asked for 2} years’ morato- rium, the third london conference and the reparation commis- sion suspended cash payments, and agreed to accept the balance of instalments for 1922 in six months’ bills at 43%. it was laid down that further default would bring about the seizure of productive guarantees. in nov. the german govt. replied requesting a definite moratorium and the revision of the total payments. they asked for time to carry out the plans for stabili- sation recommended by the currency experts. the british proposals of jan. 1923.—in jan. 1923 there was a conference in paris of the prime ministers, when a somewhat complicated proposal was put forward by britain for an issue of so milliards of “‘ a” bonds maturing in 1954, with interest deferred entirely for the first four years, and 1% for the next four down to the end of 1930. there was to be an issue of “‘ b ”’ bonds, to be definitive unless germany proved to a tribunal before april 1933 her inability to meet the payment, and deliveries in kind were to be continued for determined amounts, with any excess to be set off against the bond interest. this plan was linked up with the question of inter-allied debts and their cancellation. germany was to agree to the currency stabilisation plan recommended by the foreign experts a few weeks previously. she was to balance her budget within two years and accept a foreign finance supervision which should supersede the repara- tion commission in all executive functions. there were also conditions as to germany’s forfeiture of customs and the alloca- tion of loans, issued in the allied markets, to the redemption of the bonds. at the same time the french prime minister put forward a proposal to adhere to the capital sums determined in may 1921, with a moratorium of two years, giving germany the power to repay under discount. the customs were to be retained as productive pledges, and the reparation commission were to take control of german finance. trance agreed that if any of her debts to the allies were remitted, she would be prepared to consider the question of reducing germany’s total indebtedness. the ruhr occupation.—during the comparative deadlock that followed, france began to carry out her proposals for the occupa- tion of the ruhr. in the immediate ensuing period considerable doubt existed as to the effect of the occupation upon repara- tions, but by may and june the germans had become thoroughly alarmed, and their proposals for the evacuation of the ruhr valley and the restoration of germany’s economic freedom, were contained in special german notes the net effect of which was that the capital debt should be fixed at 30 milliard gold marks, of which 20 milliards would be covered by an international loan in july 1927, 5 milliards two years later, and 5 milliards by july 1931, the proceeds to be given over to the reparation commis- sion. as guarantees for the service of these loans they were to mortgage the railways for 1o milliards, yielding 500 million gold marks per year; 500 million from the general mortgage on the industries and natural resources of germany and, thirdly, the pledge of their consumption taxes, i.¢., luxury, tobacco, beer, wine and sugar, to an amount probably exceeding 200 million gold marks. reparations and the dawes plan germany suggested an international conference to determine their capacity to make further payments. the effect of inflation and the general disintegration of german finance, became very marked, and germany’s whole constitutional fabric was in grave danger. (see germany: economic history.) appoiniment of the dawes committee—towards the end of the year active steps were being taken to set up an international committee of experts to consider germany’s position, and to make proposals for stabilising the currency and balancing the budget. the credit for this proposal has been variously assigned to mr. hughes of the united states, to sir john (afterwards lord) bradbury on the reparation commission, and to the international chamber of commerce conference at rome. the representatives of this committee were in form chosen by the reparation committee and appointed by them. but their selection was made a matter of government interest in each country, there being two representatives from france, belgium, italy, great britain and the united states respectively. the chairmanship was put into the hands of the united states in the person of general dawes, and this commission became afterwards known as the “‘ dawes committee,” and its report as the “ dawes report.’’ the personnel of the committee was as follows: united states—general charles g. dawes, owen d.- young; great britain—sir robert kindersley, g.b.e., sir josiah stamp, k.b.e.; france—j. parmentier, professor alex; italy—dr. alberto pirelli, professor flora; belgium—fe. franqul, baron houtart. (there was a second committee under the chairmanship of the rt. hon., reginald mckenna, set up “ to consider the means of estimating the amount of german exported capital and of bringing it back to germany.’’) ii. the dawes report the dawes committee began its meetings in paris on jan. 14 1924 and reported on april 9 1924. although neither the evacuation of the ruhr nor the question of reparations was mentioned in the terms of reference they really were in the fore- front of the task. in the first place, so long as the occupation of the ruhr continued and germany was not a complete fiscal unit, she had not entire control of her receipts and expenditure, and there could be no guarantee of a balanced budget. in the second place, the reparation liabilities under the treaty figured amongst the budgetary expenses, and if in excess of budgetary possibilities, made it impossible to guarantee that steps taken for the stability of the currency would be permanent and effec tive. the question of reparations, therefore, figured prominently in the report. general principles.—the report adopted a business attitude and considered political factors only in so far as they affect the practicability of the plan. it sought the recovery of debt, not the imposition of penalties, regarding the payment of that debt by germany as her necessary contribution to repairing the damage of the war. the committee recommended it as in the interest of all parties to carry out this plan in good faith, these assurances being paramount having regard to the temper rul- ing at that time, and the suspension of motives. they avoided the political guarantees which had been so prominent hitherto and proposed only economic ones. ‘they were emphatic that for success in stabilising currency and balancing budgets, germany needed the resources of german territory as defined by the treaty of versailles, and free economic activity therein. on the vexed question of military “ sanctions ’’ and occupation which were strictly beyond their terms of reference, they confined them- selves to stating ‘“‘within the unified territory, the plan requires that, when it is in effective operation:— 1. if any military organisation exists, it must not impede the free exercise of economiic activities; 2. there shall be no foreign economic control or interference other than that proposed by the plan.” the report treated stabilisation of currency and the. balancing of budgets as interdependent, though provisionally separable for examination, and insisted that currency stability could only be maintained if the budget were normally balanced; while the reparations and the dawes plan budget could only be balanced if a stable and reliable currency existed. both were needed to enable germany to meet her internal requirements and treaty payments. they laid stress upon germany’s economic future as indicated by her productive power, plant capacity, increasing population, technical skill, material resources and eminence in industrial science. organisation of the reichsbank.—in their proposal for the stabilising of the currency they suggested that a new bank be set up or the reichsbank reorganised. the main characteristics of the bank were given:— i. to issue notes on a basis stable in relation to gold, with an exclusive privilege; 2. to serve as a bankers’ bank, establishing the official rate of discount; 3. ‘fo act as the government banker, but free of government control: 4. advances to government to be strictly limited; 5. to hold on deposit reparation payments; 6. the capital of the bank will be 400 million gold marks; 7. it will be directed by a german president and managing board, who can be assisted by a german consultative committee; 8. the due observance of its statutes will be further safeguarded by a general board, of which half of the members, including a commissioner, will be foreign. they were emphatic that even granted full economic and fiscal sovereignty, balancing the budget would necessitate a period of relief from reparation payments, though the pressure of political interests was too great to allow of a complete suspension of deliveries in kind. although the budget might be balanced without the total capital debt of germany being fixed, they maintained it could not be continuously balanced if there were any uncertainty as to the maximum avs#ual charge that would fall upon it for some years, on a basis clearly prescribed in advance. the report deferred to the principle that the german people ought to bear a burden commensurate with that in the allied countries, and they claimed to apply the principle “to the full limit of practi- cability.” the transfer committee—a transfer committee of an inter- national constitution was set up to control the “ delivery ”’ programme, to receive the payments in marks in germany, and to be responsible for the extent to which, and the way in which, these sums were transferred abroad in foreign currencies. thus the mistake of forcing germany beyond the economic point in the purchase of foreign currencies, which had been made in the past, was guarded against for the future. no attempt was made, as it was outside the terms of reference, to assess the /ength of time during which these payments should be made, or the total amount of the reparation debt, but it was clear that the amount to be paid in the standard year, viz.: 23 milliards would not do more than pay the interest on a portion of the liability imputed under the treaty. it was provided, however, that the payments in the standard year should be increased with the increasing prosperity of germany, the measure to be determined by an ‘index of prosperity ” based upon comparative statistics of imports, exports, public revenues, population, consumption of sugar, etc. in this way it was at least possible that the sums ultimately payable annually would be greatly in excess of the 23 milliards in the standard year. in the event of the economic circumstances of germany’s foreign trade being such that the transfer committee could not succeed in transferring the whole sum to the allies, it was provided that there should be an accu- mulation in germany up toa limit of 5 milliards, at which point, if necessary, the payment should be reduced. the report set out the varying economic principles under- lying reparations which up to that time, had not been generally recognised by the public, or acted upon by politicians. it was laid down, for example: there has been a tendency in the past to confuse two distinct though related questions, 7.e., first the amount of revenue which germany can raise available for reparation account, and, second, the amount which can be transferred to foreign countries. the funds raised and transferred to the allies on reparation account cannot, in the long run, exceed the sums which the balance of payments makes it possible to transfer without currency and budget instability 337 ensuing. but it is quite obvious that the amount of budget surplus which can be raised by taxation is not limited by the entirely dis- tinct question of the condition of external transfer. we propose to distinguish sharply between the two problems, and first deal with the problem of the maximum budget of surplus and afterwards with the problem of payment to the allies. in the past, the varying con- clusions formed as to germany's “ capacity’ have often depended upon which of these two methods has been chosen. schedule of payments.—the provisions made for payment under the treaty were as follows:— . million budget; moratorium period: gold marks first year: from foreign loan and part interest (200 millions) on railway bonds; fotal of a ; j - s : . 1,000 second year: from interest on railway bonds (including 130 millions balance from first year) and interest on industrial debentures and budget contribution, in- cluding sale of railway shares; total of ; . ‘ 1,220 transition period: third year: from interest on railway bonds and indus- trial debentures, from transport tax and from budget; total of ; , : . : . 1,200 subject to contingent addition or reduction not exceed- ' ing 250 gold marks. fourth year: from interest on railway bonds and indus- trial debentures, from transport tax and from budget; total of . ; . : . 1,750 subject to contingent addition or reduction not ex- ceeding 250 million gold marks. standard year: fifth year: from interest on railway bonds and industrial debentures, from transport tax and from budget; total of . 2,500 the first year was to begin to run from the date when the plan should have been accepted and made effective. these payments were to be absolutely inclusive of all the various ex- penses for military purposes that were being thrown upon germany. they were also to include the value of deliveries in kind. securities for payment.—the “ securities ”’ proposed were of three kinds: taxes, railways and industrial debentures. as regards railways, the whole system was to be made over to a company and be no longer directly under the reich. railway bonds were to be set up. eleven milliards of first mortgage railway bonds against a capital cost of 26 milliards to be created for reparations; these bonds to bear 5°, interest and 1% sinking fund per annum; in view of reorganisation, interest to be accepted as follows:— 1924-5 330 million gold marks. 1925-6 465 million gold marks, 1926-7 550 million gold marks. 1927-8 and thercafter: 660 million gold marks. behind the bonds there were to be created :— z milliards of preference shares to be reserved for sale to the public an 13 milliards of common stock. | three-fourths of the proceeds of the preference shares was to be applied, as required, to the payment of debt and for capital ex- penditure of the railways. the remaining 500 millions of prefer- ence shares and all the common shares were to go to the german government. they assigned the transport tax to the extent of the first 290 million gold marks for reparations. industrial debentures were recommended: five milliards of industrial de- bentures were to be provided for reparation; these bonds to bear 5° interest and 1°% sinking fund, t.e., 300 million gold marks per annum. pending economic restoration, interest and sinking fund were to be accepted as follows: first year nothing second year 125 million gold marks third year 250 million gold marks. thereafter 300 million gold marks. as further guarantee, they proposed to pledge certain revenues as collateral security, 7@.¢e., the taxes on alcohol, tobacco, beer and sugar, and the customs, but only up to definite limits. an arrangement for control, simple in the ordinary course, but be- coming drastic if circumstances demanded, was recommended. 338 the new organisation therefore required a trustee for railway and industrial bonds, three commissioners of (1) railways, (2) the bank, (3) controlled revenues, and they recommended an agent for reparation payments to co-ordinate the activities of the above and to preside over the transfer committee. the feature of the plan on which its whole inception depended was the raising of a foreign loan of 800 million gold marks, which had to serve the double purpose of a gold reserve and also financing the internal payment for the treaty in 1924-5. the report claimed to take the question of ‘ what germany can pay ” out of the held of speculation and put it in the field of practical dem- onstration. iv. adoption of the report the reception of the report was immediately favourable, and it was finally adopted by the governments concerned in the lon- don agreement on aug. 30 1924. steps were immediately taken to put it into opcration. so far as all formal acts and the setting- up of the machinery for the future working of the plan are con- cerned, it may be said that everything has gone satisfactorily. the reparation commission have officially stated: ‘‘ germany is faithfully fulfilling her reparation obligations as far as they are at present fixed.”’ the actual test of the working of the full apparatus will come later, since the reparation payments to be made by germany in its early stages are comparatively negligi- ble. that a new spirit has been secured is beyond question. the first report of the agent-general, mr. s. parker gilbert, says: it is too carly to draw conclusions regarding the ultimate effects of the plan. broadly, it is an endeavour to stimulate confidence among peoples and to apply principles of reason and justice to a difficult, vital problem. the success of the plan will be measured not alone in terms of payments effected. it will be determined also by the extent to which it helps to replace distrust and discord with con- fidence and conciliation. its early operation has fulfilled expecta- tions. the pivot of the whole plan for the first year was the german external loan of 40 millions sterling or 800 million gold marks. in the words of the report, this was necessary to assure currency stabil- ity and financing essential deliveries in kind during the preliminary period of economic rehabilitation. it enabled the allies to receive something on account of rep- arations without, at the same time, any burden being placed upon the german budget. negotiations were completed on oct. 10 1924, and on oct. 13, the reparation commission constituted the service of the loan as a first charge on all the payments pro- vided for under the plan, and also on the collateral security of the controlled revenues, and any other assets or revenues of ger- many to which the powers of the commission extended under the treaty. the transfer committee at its first meeting recognised million gold marks | million receipts gold | marks payment to various allied countries expenses of: reparation com- mission . . 5:6 pee and high ‘om. . . or military gone al control e of naval com. of control 0-07 22.8 european commis- sion of the danube service of german external loan on account of admin- istration cost of office for reparation pay- ments, and discount on railway payments in advance cash in hand, aug. 31 1925 payments | cash withdrawn from proceeds of german external loan, 1924 interest on railway bonds... exchange differences and interest received 789-0 800-0 200°0 o'5 3°9 107-0 1,000-5 total . .. | 1,000-5 reparations and the dawes plan the priority of the loan, and gave it an absolute right of remit- tance irrespective of the effects upon the exchange. this loan provided 800 million gold marks out of the total of 1,000 million gold marks, which constituted the first year’s annuity, and the balance of 200 million gold marks came from the german rail- way company as interest on the bonds. apart from this 200 millions, there was no drain whatever on the current resources of germany for the first year. first year's working of the plan.—the first complete year of the dawes scheme is shown in the preceding table of receipts and payments. the distribution of the 893-5 million gold marks inclucles 48-6 million gold marks for miscellaneous deliveries to the smaller claim- ants, leaving 740-4 millions for the four chief interests distriluted as follows:— (million gold marks) ct sf) ~ s 5 = _—_ om in oe = = rb +o on : 8 oe |—3 cu kx _ foal 35 — oa a) c s ve) ° oo | - e |e le le arising on account of repa-| ration recovery acts 155-2 | 25:1 180°3 cost of armies, requisitions, cles 3 : : 30°2 | 144°2 20'7 | 1951 delivery of dyestuffs, etc., and receipts in kind 4°5 | 227°3; 60:4] 72:8 | 365-0 total thus 49° has been transferred as deliveries in kind, 263%) for occupation expenses, and 243% has been forthcoming from the reparation recovery acts. france has received 50°%; great britain (including the domin- ions), 24%; belgium, 12%; italy, 73°, and other allies, 63%. under the agreement of jan. 1925 the united states are to get 2} %, to be contributed proportionately by the other participants. the transfer committee have had time to examine their prob- lem before having to take any executive action on its chief dith- culties. they have not been called upon to decide delicate ques- tions of exchange priority or pressure. their first year has been taken up in making arrangements for deliveries in kind and rep- aration recovery acts. the latter in particular presented diffi- cult questions which have been described by the agent general in his report. by forcing the german exporter to look to the german govt. or agent general for the deductions made by the british govt., in respect of a total which had no relation to the dawes plan or to the sums transferable by the transfer commit- tee, the british govt. could virtually ride round the powers of the committee, “‘ confronting them with an accomplished fact.” in the report of the negotiations between the british treasury and the agent general, it was arranged for the german exporters as a whole to deliver to the reichsbank monthly 30% of the ster- ling proceeds of their exports to great britain. deposits are made at the bank of england for credit to the agent general’s account. the transfer committee regains control and the system adjusts itself automatically to the british govt.’s share in the available annuity. towards the end of 1925 germany passed from a stage of com- paratively easy conditions into an industrial crisis which may retard the full development of her fiscal resources towards the position demanded by the third year of the plan. vy. the industrial aspects of reparations it has been increasingly realised by the industrialists of the allied nations that, just as the payment of reparations by ger- many involved the necessity for her to maintain an export sur- plus, so the recipient countries may derive all they need of the goods involved by imports from germany at the expense of the competing industries in the allied countries, and that even if the surplus of german goods should go to neutral markets they may serve only to displace similar goods hitherto exported from the allied countries. hence the anomalous situation has arisen that reparation payments, speaking generally, have been ar- dently desired by the creditor governments, but speaking repertory theatre—republican party particularly, have been feared and resisted by the business men in the same countries. the committee on economic restoration of the international chamber of commerce in nov. 1924 set up a sub-committce (sir josiah stamp, dr. alberto pirelli and count andre de chalendar) to study the question of international transfers of reparation payment. one report signed by all three, and a sup- plementary one by the english member, were presented in may 1925, and adopted at the conference in brussels in june 1925. the chief items and recommendations were:— the solution of the “balance of trade” problem in relation to the liabilities under the dawes plan, is to be found in the following order:— 1. by a considerable expansion of german exports to gencral world markets in the ordinary course and under those conditions normal to germany without any special overhead organisation or effort. this carries with itself the possibility of cash payments to the allied govts., which is, of course, the ideal form for the latter of receiving reparation payments, 2. by arrangements between each allied creditor country and germany with a view of developing, in the widest possible manner compatible with national interests and the obligations of the transfer committee, deliveries in kind or services. this, though possibly in the long run not a major part of the total, is important. serbia may want locomotives which she does not produce. italy may want coal which she may not possess, france or great britain may want dyestuffs or potash. these are merely examples of a wile range of goods which germany can probably deliver without difficulty. 3. by the operation of certain international co-ordination in en- terprise and public works, by research and study and practical action, of which we have in this report, given an illustration called “ as- sisted schemes.” 4. where the three foregoing still leave a gap between the accumu- lation of reparation marks and their effective transmutation into external values, it may be possible to gain time and to defer the greater difficulties of forcing the plan by two methods (a) the sale of railway, industrial and eventually other german bonds on the international markets and (b) by making permanent investments in germany which will belong to non-allied or neutral holders. ‘the method (a) above may play a very important part, either as re- demption of capital debt or for the balance of the annuities. it must not be forgotten, however, that the extensive use of the plan throws a burden upon the future export surplus in addition to the fixed annuities. the system under (}) finds certain limitations under the dawes plan and in practice, but it may be e.g., that an argentine resident or a brazilian will become the owner of property in ger- many, or of shares in german companies, by means of the export of food or raw materials to allied individuals. these sales, as also these loans, are not an immediate method of externalising german wealth, but they, so to speak, stave off the day of difficulty and gain time. the difficulty of exporting £1,000 outright is transmuted into the smaller difficulty of transferring £50 or £60 interest thereon an- nually in perpetuity, a difficulty capable of rectransmutation into capital at some distant date after the export surplus ts no longer monopolised by reparation payments, by germans buying in the investments held by forcigners in their own country. while theoretically the ‘‘demand” of individuals in the allied countries will be so increased by relief in taxation that it could, zm amount, absorb a new supply of german goods, the demand will not fully coincide in kind with the goods which are offered. there may be, in consequence of this maladjustment, important reactions in price which will make the burden greater for germany to discharge, make full transfers difficult, and induce unduly severe competition in certain markets. moreover, vested industrial interests in both capital and labour in the allied countrics may be adversely affected, and for various reasons, if the whole question is left to uncontrolled economic forces political difficulties will arise. we have certain suggestions to make for co-ordinated and sys- tematic international action which, while it may not affect a large sum in relation to the whole reparation annuity, may be of great importance in assisting a settlement of this residual problem, we conceive that there is everything to be gained by systematic study and the existence of a ‘‘safety valve” in the event of normal channels being inadequate for the purpose, to relieve the concentrated com- petition, and also to prevent the consequences of accumulation of reparation payments in germany. our proposal would tend to pre- vent existing channels of german trade being flooded by excessive supplies and by a prepared plan irrigate, without disaster and with ultimate profit to the world, a wider area than could otherwise be open. the international chamber have decided to prosecute the idea of assisted schemes, and are setting up an organisation to elaborate them. as soon as the dawes scheme has had time to operate, it will be seen whether “ transfers ” on the basis suggested are practi- 339 cable or not. in any case, it is anticipated that the question of the total amount on the duration of the reparation scheme will again come forward for consideration, and the difficult diplo- matic questions relating to so-called “‘ modifications of the treaty ”’ will have to be settled. | bin_riograpiy.—j. m. keynes, the economic consequences of the peace (1919); j. m. keynes, a revision of the treaty (1922); h. g, moulton and c. fe. macguire, germany's capacity to pay (1923); if. g. moulton, the reparation plan (1924); g. calmette, recuett de documents sur l'histoire de la question des reparations, 1o1r9o—s§ mai 1921 (1924); reports of the export committee appointed by the reparation commission (1924); and other government publica- tions; report submitted to the commitiee on economic restoration of the international chamber of commerce (1925). various pamphlets on the dawes plan and kindred matters have been published by the world peace foundation. (j. st.) repertory theatre: see drama. repin, ilja jefimovich (1844-1918), russian painter (see 23.105), died at knokkala, on the finnish frontier, july 17 1918. repington, charles a. court (1858-1925), british mili- tary critic, was born jan. 29 1858 and commissioned in the rifle brigade in 1878. after serving with distinction in the afghan war, the sudan and south africa, he was appointed military attache at brussels and the hague in 1900, being then a lieuten- ant-colonel. two years later his military career ended abruptly through domestic causes, and he took up journalism, becoming military correspondent of the tintes in 1914. tis resignation was a loss to the army, for his abilities had marked him out for high command, but in his new sphere he was able to render notable services to the cause of national security, and was also several times employed on delicate missions abroad. in 1911 he was appointed editor of the official army review, but as he retained his post on the times the appointment aroused parlia- mentary criticism and was terminated in 1912. in 1915, after staying with the british commander-in-chief in france, he came home to call attention to the shell shortage. in jan. 1918 a divergence of views caused him to leave the times for the morning post, and after the war he became military correspond- ent of the daily telegraph, a post which he held till his death at hove, sussex on may 25 1925. his works include vestigza (r919); the first world war, ror4-8; personal experiences (1920); after the war; a dtary (1922); policy and arms (1924).",
    "source_url": "https://archive.org/details/encyclopaedia-britannica-encyclopaedia-britannica.-3-encyclopaedia-britannica-inc.-1926",
    "observed_at": "2026-05-17 12:14:22",
    "integrity": {
        "hash_check": "match",
        "hash_scope": "full_normalized_text",
        "computed_sha256": "4e6527f3985aeeec8da31c9a2a2a7cd06b01a437679f779dce239ec047ddce35"
    },
    "machine_use": {
        "read": true,
        "cite": true,
        "decision": "verified_public_domain_text"
    },
    "goguides_data_license": "https://www.goguides.com/data-license",
    "goguides_data_license_version": "2.0",
    "documentation": {
        "white_paper_url": "https://www.goguides.com/white-paper.php",
        "pdf_url": "https://www.goguides.com/whitepapers/goguides-ai-source-clearance-white-paper.pdf"
    }
}