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    "chunk_id": "1926:thermit:29c7f35aad69",
    "title": "THERMIT",
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    "verified_text": "thermit is a mixture of aluminium powder and iron oxide. on ignition the reaction, 8al+3fe3;04= gfe+4all0sz, gives a temperature estimated to be between 2,300° and 2,700° centigrade. the reaction, stated in weights, means that 217 parts of aluminium plus 732 parts magnetite (iron oxide) equals 540 parts steel plus 4og parts slag, or approximately, three parts of aluminium plus ro parts of magnetite will produce, on combustion, seven parts of steel. this steel represents about one-half of the original thermit by weight and one-third by vol- ume. discovery.—thermit was discovered by dr. hans gold- schmidt, of essen, germany, in 1895, while trying to reduce chromium and manganese. dr. goldschmidt’s principal dis- covery related to a simple and safe method of ignition, as the action of aluminium when mixed with various oxides, sulphices and chlorides was well known. fine aluminium will not burn below the temperature of molten cast iron, and previous experi- menters had resorted to heating their mixtures inacrucible. this made the initial temperature so high at the moment of ignition that there was an explosion. dr. goldschmidt obtained ignition of a cold mixture by means of a barium-peroxide fuse, which was set off by a storm match. later, magnesium powder or ribbon was used, being set off in the same way. a red-hot iron rod may also be used to set off the magnesium, which in turn ignites the thermit. dr. goldschmidt’s original american patent no. 615700 was granted march 16 1897 and related principally to the use of aluminium as a reducing agent for the production of carbon-free metals such as cobalt, chromium, magnesium, tung- sten, etc., by what is now known as the aluminothermic process. thermit is now used considerably in the foundry for purifying iron and stecl in the ladle. for this purpose the thermit is placed in a can on the end of a rod and plunged to the bottom of the molten metal. the intense heat generated tends to liberate many impurities which are carried away in the slag. the prin- cipal and better-known use, however, is in welding. thermit welding —two methods are employed, known as the plastic and the fusion. the first is used for welding pipe and the latter for solid or large sections. in the plastic method, in which the thermit is used merely for heating purposes, the ends of two pieces of pipe are machined square and clamped in a cast- iron mould with the ends butted together. this mould is in two parts, so arranged that the pipe ends may be forced together when heated. the thermit is placed in an open-top crucible lined with magnesia-tar, and ignited. after the reaction takes place, the slag rises to the top of the molten metal, and is first poured into the mould as shown at the left in figure 1. this slag forms a protective coating on the pipe and on the inside of the mould, and keeps the thermit from melting or burning through. at the right the thermit is shown flowing into the mould and forcing out the bulk of the slag, but leaving a coating as mentioned. when the pipe ends become plastic they are forced together, completing the weld. after cooling, the mould is easily knocked off, since the slag coating prevents adhesion. to weld a pipe takes from 2 to 13 minutes. | in fusion welding on solid sections, in which the thermit mix- ture forms a casting holding the parts together, a special v- shaped magnesia-tar-lined crucible, open at the bottom, is used. the hole in the bottom is closed by a headed plug, covered with refractory sand, which may be pushed upward. this crucible is placed over the mould, the proper amount of thermit put in and ignited. after the reaction, which takes about 35 sec., the plug in the bottom is pushed up and the molten thermit allowed to run into the mould. in this method great care is taken to keep 771 the slag from contact with the surfaces to be welded, and conse- quently enough thermit must be used to fill the mould before the slag on the top of the melted metal can enter. a typical mould for heavy sections is shown in (figure 2). in preparing to weld, the surfaces to be joined should be cut or set so as to be § in. or more apart. yellow wax is then built up around the joint in the same shape as the weld is to be. next the mould box is placed and sand rammed up round the wax, wooden patterns being placed for the pouring gate, riser and preheating gate. the mould is vented, the patterns withdrawn and a gas or oil flame used to melt out the wax. the heating is continued until the sections to be welded are red-hot. this prevents chilling of the thermit, which is poured in after the preheating gate has been plugged. the steps in making a typical thermit weld on a locomotive frame are graphically shown in (figure 3). thermit welding is largely used in repairing broken rudder frames, pro- peller shafts, locomotive frames, steel rolling-mill pinions and other heavy sections, but it cannot be economically used for welding thin sheet metal sections. welds have been made where from 3,000 to 4,000 ib. of thermit were used. for commercial purposes there are now produced three varieties of thermit, known as plain thermit, railroad thermit and cast-iron thermit. the plain thermit is simply a mixture of aluminium and iron oxide, as already given. railroad thermit is plain thermit with the addition of §°% nickel, 1% manganese and 15% mild steel punchings. cast-iron thermit is plain thermit with the addition of 3% ferrosilicon and 20% mild steel punchings. the names of these mixtures indicate their principal uses. (e. v1.) thermodynamics: see heat. thermo-electric pyrometer.—the thermo-electric py- rometer is most generally used for measurements of high tem- peratures in industry, such as the temperatures of furnaces of all kinds as, for example, for annealing, hardening, tempering, carbonising or case-hardening; blast furnaces; the temperatures of molten metals; the temperatures in galvanising, tinning, lead and salt baths; the temperatures in various processes in brick, tile, pottery and glass works, and the many temperatures through- out an efficiently operated boiler-plant. the pyrometer is also used to determine the recalescence points of stecl, the freezing points of alloys and in connection with general research work in the laboratory. general principles —if two wires of dissimilar metals are joined at their ends to form an electric couple, and one junction is heated, an electromotive force is set up which gives rise to an electric current in the circuit. the magnitude of the electro- motive force depends upon the difference in the temperatures of the hot and cold junctions. if a millivoltmeter, by means of which the electromotive force generated can be measured, is introduced into the circuit, it is consequently possible to deter- mine the temperature of the hot junction, provided that the cold junction temperature and the relation between temperature and electromotive force for the two metals used are known. the circuit can thus be used for the measurement of temperature, and a thermo-electric pyrometer consists essentially of a thermo- electric circuit in which the hot junction is exposed to the tem- perature to be measured, and the resulting electromotive force is measured by an indicating or recording millivoltmeter, which for convenience is usually graduated to read directly in degrees of temperature. : in a simple thermo-electric pyrometer the cold junction is placed in a constant temperature vessel, such as a vacuum flask. the two dissimilar wires, suitably insulated and protected, form the thermo-couple which is exposed to the temperature to be measured, the ends of the thermo-couple wires being connected to a millivoltmeter. the introduction of the millivoltmeter and connecting leads makes no difference to the electromotive force generated. suitable metals must be chosen for the thermo-couple wires, the essential points being that the electromotive force developed by the junction should be sufficiently large and should increase as regularly as possible as the hot junction temperature rises, and that this electromotive force should not be altered by prolonged heating of the thermo-couple. since the electromotive snr omy i | force generated by the thermo-couple is affected by changes in the cold junction temperature, various methods have been cle- vised for maintaining a steady cold junction temperature, such as, for example, the use of compensating leads which have the effect of transferring the cold junction from the thermo-couple head to some position less subject to temperature variations, or the immersion of the cold junction in a vacuum flask, or in an electric thermostat. simple thermo-eleciric circuit—in practice, a simple thermo- electric circuit is composed of the following parts:—(a) a thermo- couple, or hot junction, which receives the temperature; (}) a length of connecting leads, with or without a junction box, to make electrical connection between the thermo-couple and the millivoltmeter; (c) a millivoltmeter, which may be either an indicator or a recorder. frequeztly it is desirable to have both these instruments, in which case a switch is usually required at the indicator. multi-point thermo-electric circuit-——a multi-point thermo- electric system is similarly built up of items which may be sub- divided as follows:—(a) a thermo-couple or hot junction at each point where the temperature is to be measured; (4) a system of leads and junction boxes; (c) a millivoltmeter, which may be an indicator or a recorder. in combined outfits one indicator can be used in conjunction with one or more recorders. in addition a selector switch is required at the indicator, and sometimes a selector switch is required at the recorder. in addition to the above parts, and particularly for accurate work at moderate temperatures, as, for example, in outfits for determining the temperatures of stator windings, a cold junction is provided which forms a separate unit. (fe j.-d.) thermometer: see kata thermometer. theunis, georges (1873- ), belgian politician, was born at montegnee, near liege, feb. 28 1873. in jan. 1916 he attended the inter-allied relief commission in london and in 1org represented belgium on the reparations commission. in 1920 he became finance minister in m. carton de wiart’s coalition ministry, the aims of which government were first to settle the reparations question, with due regard to belgium’s prior claim and secondly to maintain the entente between the allies. m. theunis represented belgium at the inter-allicd conferences of san remo 1920, london 1924 and paris 1925, which resulted in the adoption of the dawes plan and a corre- sponding inter-allied settlement. his home policy was to place belgian finance on a sound basis and to reconstruct the devas- tated regions. his cabinet resigned in april 1925, after the elections in which the democratic parties triumphed. in aug. 1925 m. theunis was sent by his government to washington to discuss the question of the belgian debt to u.s.a. this mission resulted in an agreement which was submitted to the parliaments of the two countrics. third (communist) international, the.—the com- munist international (abb. komintern) is the international organisation of the communist party of all nations, founded in 1919. it is also called the third international. in structure and programme it differs from the first and second. com- munism sympathises unreservedly with the first international, founded under the leadership of marx and engels, whose policy was essentially one of active revolution. as, however, its organisation lacked a definite central point and had not its roots in party associations, its practical manifestation, the paris commune, was bound to fail. lenin evolved his theory of revolutionary movement from the lessons of the failure of the commune, and arrived at the conclusion that a successful revolution might begin as a spontaneous popular upheaval, but could only achieve and retain victory in the form of an organised and systematically controlled movement. the first international lost its practical importance after the collapse of the commune. birth of the third international —in 1889, when the socialist labour movement had recovered its force, the second i[nter- national (¢.v.) was founded. up to 1914 this represented the in- ternational organisation of the socialist labour movement as a whole. the constructive importance of the second inter- thermometer—third (communist) international national, from the point of view of the communist parties, lay in the fact that it organised and grouped labour in trade unions, co-operatives, educational associations and political parties. the second international already contained a bolshevik opposi- tion which refused to assimilate with the larger body. it was led by lenin, who was a member of the international bureau (b.s.i.) of the second international in r914. in 1914 the second international collapsed. the communists date the epoch of the communist international from this moment. this epoch emerged out of a transitional! period comprising the first three years of the war, during which lenin struggled to “ transform the imperialist war into a civil war.’”? the foundations of the third international were laid at the conferences of zimmerwaldd and kienthal in switzerland. it only achieved real authority, however, when the leaders of the german army conceived the ilea of making the russian february revolution more extreme. the german supreme command brought lenin and trotsky to russia in the fond hope that the fire of the russian revolution which they were kindling in russia would stop at the frontiers of germany. the third international was not formally founded till march 1919. up to that date the communist parties believed that they would be able to break up the socialist parties from within and transform the second international bodily into a com- munist organisation in the tempest of the world revolution. especially during the episodes of the soviet republics in bavaria and hungary, and even after their collapse, during the labour troubles in britain, germany, italy, etc., moscow continually believed the outbreak of world revolution imminent every hour, and expected that the socialist parties could be simply absorbed in the communist parties. as it grew ever plainer that this hope (which at first was shared by lenin) was utopian, the communists devoted even greater energy to tl.cir own inter- national. fundamental principles —the following are their basic prin- ciples:— 1. the communist international is the organisation of the com- munist parties of each nation; it is therefore revolutionary. its chief purpose is to accelerate the development of events towards world revolution. it rejects any compromise or co-operation with bour- geois parties. similarly it rejects parliamentarism as a normal method of political development. in certain circumstances it ad- vocates a unity of front with socialist parties, including the second international. this is, however, never more than a temporary and tactical co-operation. the communist international is honest enough to state openly that it is only ready to support the socialist parties so far as “ the hangman’s rope supports the convict.’”’ the aim of the communist international is the creation of really revolu- tionary proletarian parties which shall be the advance-guard of the revolution, and the combination of them in a great homogencous in- ternational communist party. their headquarters are only “ for the moment,’ as lenin said, and probably not for long, in moscow; later they will move to countries where the economic system and the proletariat alike are more advanced, so soon as one such country achieves a sovict constitution. 2. the communist international is no loose organisation like the second international, but an association bound together by a com- mon programme and principles, and receiving its orders from a cen- tral organ, the bureau of the third international. this central organ does not merely issue general rules of conduct, which may be carried out or not by the individual national parties according to their own convictions and views of the general situation; it lays down policy to the smallest details. the men at the head of com- munist parties have been repeatedly changed under orders from the international, and tactics (e.g., the question of co-operation with the socialist parties, or the attitude to be adopted towards parlia- ment) have often been defined in detail by resolutions of the inter- national bureau. this central organ of the communist international is indubitably in close personal and political touch with the russian govt., the soviet of people’s commiussaries, the individual communist parties are by no means all or- ganised on the russian system. the communist parties of western europe are ‘open parties’’ which anyone may join. in some countrics the communist parties are proscribed by law. presum- ably there is everywhere an inner kernel or party ring which forms the political centre. the ideas of the periphery are inspired by this inner ring. wherever it is possible, a sort of military organisation probably also exists, exactly as in the nationalist and fascist parties. 4. in matters of internal policy the individual purties are, as already stated, strongly intluenced by the communist international, thoma—thomas, albert but there are great differences between the nations. in countries where democracy is firmly based and parliamentary tradition of long standing, the tactics of the communist parties are correspond- ingly modified. communists take part in parliament, bring forward legislative motions, ctc.; at times they even co-operate with the socialist parties. this is, however, only a temporary tactical move, the ultimate aim being always world revolution. the formation of the so-called ‘“ unified front ’? is a means to an end and a tactical move. the organised workmen in the trade unions are to be cap- tured in such a way that the trade untons gradually come under the influence of the communist parties.! developments outside the industrial prolctariat—since the aim of the communist international is world revolution, and since the state of the continent of europe has grown much less dis- turbed since 1921, the chief aim of the communist international proved unattainable. the revolution had taken the offensive at isolated points, but failed to develop into a world-wide move- ment. the international therefore put forward officially the doctrine that sudden enthusiasm alone will not bring about world revolution; this must be achieved by a strict organisation which must first be created. such an organisation, however, presupposes a compact communist international unified front. the communist international began by continuing the traditional policy of the second international. it desired to be an organisation of manual labour. but in russia the actualities of the situation soon forced the party to admit the peasants as members (at first only the poor peasant, later the medium peasant). a peasants’ international was founded in 1923, but made slow progress. nevertheless, it then became possible to embrace the extremist agrarian movement—a matter of the greatest importance in countries where large estates are com- mon. the rather unexpected pronouncement was therefore made that “‘ the peasants have become the natural allies of the workmen.” thus a link was forged with what had been the oldest revolutionary movement in europe. to-day, indeed, with the emergence of the peasants from serfdom, their status and feelings, especially in central europe, have changed radically. it is most unlikely that revolutionary feelings will ever become widespread among them. oriental and colonial propaganda.—far more important 1s the connection between the communist international and parties and currents of thought which may be described as the heart of the movement for national and economic independence among the colonial and semi-colonial territories of asia and africa. countries such as india, china and the wholly inde- pendent japan are already represented in the communist international by considerable parties; although these parties differ very markedly from those of western europe. the psychological bases for intensive communist propaganda in asia are, firstly, the appalling conditions in the newly developed enterprises (women’s and children’s labour, long hours of labour, barrack conditions for workmen); and secondly—perhaps more important—the breakdown of the social structures of these countries. throughout asia the family is the basis of society. industry destroys this, and nothing comes to replace it. but man, in the far east, cannot live except as member of a com- munity. he cannot grasp the idea of an abstract existence, se- cured simply by a contract of labour. existence is uprooted, and all his instincts revolt against an economic system which at- tempts to make him into an individual. this revolt finds its plainest expression in the communist movement, the essence of which is thus the resistance of the social instincts to the destructive influences of industrial life. furthermore, the closing of the united states and australia against foreign immigrants, the restrictions placed on indian emigration to africa, the unfortunate results which attended chinese labour conditions in south africa, combined with the 1the conditions of affiliation to the communist international prescribe that every party which desires afhliation to the c. i. must develop a systematic and persistent communist activity within the trade unions, works committees, co-operative socicties, and other mass organisations of workmen. within these organisations it is necessary to organise cells, which by persistent and continuous work must win the unions, etc., to the cause of communism. the com- munist cells must be completely subordinated to the party asa whole. 773 insistence laid by the white races on the preservation of racial distinctions, have created a real and practical feeling of unity among all coloured races and nations throughout the world— a feeling which extends throughout all africa and asia, andas far as the negroes of america. in the face of this racial antagonism, sovict russia is the only power today which stands on principle for racial equality and full equality of rights for all races on their own territory. thus communist propaganda directed against the influence of iuropean capitalists and the partisans of racial superiority in asia has an easy task. even japan has been jed by similar motives to a political rapprochement with soviet russia. com- munist propaganda in asia and africa is therefore adapted to local conditions. social and national considerations take the hirst place; less insistence is laid on the purely economic factor. the resentment against capitalist exploitation, combined with the struggle against the imperialist european powers and against the united states, inevitably draws the leaders of those movements towards russia, and thus towards the communist international, this connection has been developed by special congresses to the oriental peoples (as that of baku in 1920), and has certainly been exploited by the russian govt. to further russia’s traditional foreign policy in asia. in all these countries the small tenant farmers are particularly susceptible to the allurements of the communist programme. results up to 1925.—the communist international forms a bond between the states organised on the communist system and the communist parties in the capitalist bourgeois states. in this way one may look on its work as the ‘ formation of the front line of a world-revolution.” in fact, a country which contains a strong and active communist party finds it impos- sible to participate in an european counter-revolutionary movement. in terms of practical politics, this means that the states of europe would find it hard to undertake war against russia, in face of the opposition of their own communists and socialists. this is probably the greatest success of the com- munist international. the communist international is therefore both an association of national parties with a definite internal political programme, and at the same time an international po- litical organisation of really international importance on a world- wide scale. | 7 bibliography.—kk. marx and fr. engels, manifesto of the com- munists, 2nd ed. (inter. working men’s assn.) (1886); fr. engels, grundsdtze des kommunismus (berlin, 1923); l. trotsky, russland in der revolution, trans. by t. lerzmark,'etc. (dresden, 1910); n. lenin, staat und revolution (berlin, 1918); n. lenin, die kdchsten ausgaben der sowjet-macht (berlin, 1919); dr. max hirschberg, bolsche- wismus (munich, and leipzig,1919); n. bucharin, programine of the world revolution (glasgow, 1920); l. trotzky, die neue okenomische politik sowjetrusslands und die weltrevolution (hamburg, 1923); friedrich wieser, leopold wenger and peter klein, der staat, das recht und die wirtschaft des bolschewtsmus (berlin, 1925—bibliog- y raphy by e. drahn); manfred langhans, vom absolutismus 2um ratefreistaat (1925); dr. michael eljaschoff, die grundztige der sowjet- verfassung (1925); dr. alexander hirsch, aulturelle krdfte und wertschaftliche gestaltung im gegenwdrtigen russland (berlin, 1925). for an account of the propaganda methods of the third international and the relation of the organisation to the govern- ment of the u.s.s.r. see a. toynbee, survey of international affairs, pp. 161 to 262 (1924). (e, le.) thoma, hans (1839-1924), german painter (see 26.862), died at karlsruhe nov. 7 1924. he has published the following books since 1910: das hans thoma buch (1919); die suchende secle (1910, etc.); im winter des lebens (1919). see c. anton, hans thoma der maler (1919). thomas, albert (1878- ) french politician, was born june 16 1878 at champigny-sur-marne, near paris. his father was a baker who by great sacrifices enabled his son to receive a college and university education. albert thomas proved him- self a very brilliant scholar and in 1898 he passed with distinction into the ecole normale supericure. meanwhile he had won a scholarship entitling him to travel in russia, which he did in the same year and published his first booklet on russia a colonising nation. after a year of military service he re-entered the ecole normale and, in 1902, obtained the highest french university 774 degree, the agregation, in history and geography. afterwards he obtained another scholarship which enabled him to travel through germany and to study the german trade union movement. a sequel to this was his book le syndicalisme allemand (1903) in which his socialist faith was propounded for the first time. when, in 1904, jaures, the great french socialist, launched ? humanite he appointed thomas sub-editor, having a high opinion of his knowledge of labour questions. meanwhile thomas had been elected in the same year as municipal councillor for champigny—his first public appointment. in those days most of his activity was devoted to the trade union movement, for he had become one of the intellectual leaders of the ‘‘ reform- ist ’? section of french syndicalism, the section opposed to the “ revolutionary syndicalist ’? wing, which was then leading the “ confederation of labour.”? he also edited a most useful and constructive magazine, la revue syndicaliste. in 1908 he pub- lished in jaures’ great histoire socialiste (rg00-1908) a remark- able volume on le second empire which is perhaps his best book. during this time he acted as private tutor to the great-grandson of victor hugo, whose grandmother, mme. menard-dorian, remained a great friend and supporter of the brilliant young pro- fessor and politician. thomas entered politics in r909 when he stood for parliament as candidate for his native city and was narrowly defeated by a moderate radical. he was successful, however, in the same constituency at the general elections of may 1910 and soon made his mark in the chamher, being elected a member of the budget committee. in the same year he supported the railway workers’ general strike and strongly criticised the mobilisation of the strikers by the prime minister, m. briand. in 1912 he became reporter of the bill on the miners’ old age pension, having in the meanwhile been elected mayor of champigny. he played an important part in the battle waged by jaures and the socialists against the three years compulsory military service bill of 1913. in may ro14 he was re-elected. he joined his regiment on the outbreak of the world war two months later. after he had seen a few weeks of war service, the ‘“‘ national defence govern- ment,’ newly constituted under the presidency of m. viviani, summoned thomas and two other socialists, jules guesde and marcel sembat, to organise the production of munitions. in may 1915 he entered the cabinet as under-secretary for arma- ments and also joined the briand ministry which followed at the end of the year. towards the end of 1916 he became minister of munitions, retaining this post in the ribot ministry which followed. in april 1917 he was sent to russia where he remained for,several months and succeeded in persuading kerensky to undertake the ineffectual “‘ great offensive ’’ against the central powers which hastened the bolshevik revolution. meanwhile in france the struggle was becoming very bitter between the majority (pro-war) and the minority (international- ist) sections of the french socialist party, culminating in the stockholm conference. leader, with renaudel and sembat, of the majority party, thomas was also a strong advocate of the independence of czechoslovakia and poland and the creation of a ‘great serbia’ and a “ great rumania.” since this “ ma- jority wing ” policy was opposed by many socialists, particularly in the paris district, thomas decided not to stand again in the paris suburbs and resigned the mayoralty of champigny. at the elections of nov. 16 1919 he was returned as a socialist in the tarn, jaures’ former constituency. at the international labour conference, held in washington at the end of the year, thomas was elected director of the international labour bureau, and as such he did much valuable work for labour both in france and abroad. a year later he resigned from parliament owing to the claims of his work at geneva, but remained a member of the “right ” section of the french socialist party. for this /ucy- clopedia m. thomas has written on corporation and the inter- national labour organisation. (j. lo.) thomas, augustus (1857- ), american playwright, was born in st. louis, mo., jan. 8 1857. he was educated in the public schools, for several years worked in railway freight thomas, augustus—thomsen offices, and, after serving as special correspondent for various newspapers, became in 1886 editor and proprietor of the kansas city (mo.) mirrer. he wrote a play, £ditha’s burglar, based on mrs. burnett’s story of the same name, which was first pro- duced at st. louis in 1883 and subsequently presented with great success at the madison square theatre in new york in 1889. his play alabama (1891), depicting the old-time south, contributed to the removal of sectional prejudice resulting from the civil war. he was elected to the american academy of arts and letters in 1912. his numerous dramas include in miszoura (1893); the hoosier doctor (1898); oliver goldsmith (1900); arizona (1900); soldiers of fortune (1902); the earl of pawtucket (1903, highly successful in england); afrs. leffingweil’s boots (1905); jim de lancey (1905); the witching hour (1907-8); as a man thinks (1911); and the copper- head (1917). in 1922 he published his reminiscences, the print of my remembrance. thomas, edward (1878-1917), british author and poet, was born on march 3 1878 and educated at st. paul’s school and at lincoln college, oxford. his first book was a volume of nature studies, the woodland life (1897), but the first notable collection of his reflective essays was jzorae solitariae (1902), the predecessor of several similar, such as rest and unrest (1910) or cloud castle (1922). among a good many miscellaneous works should be noted his critical studies of george borrow (1912); swinburne (1912); and walter pater (1913), and a volume of stories, four-and-iwenty blackbirds (1915). but the fullest revelation of his sensitive, beauty-loving nature came when he began, under the influence of his friend robert frost, the american poet, to write poetry. his verse appeared in rgt7 in reviews signed “ edward eastaway,” a volume of poems under his own name following in that year. serving with the royal garrison artillery, he was killed in france in april 1917. his lust poems appeared in 1918, and collected poems in 1920. thomas, james henry (1878- ), british politician, was born at newport, mon., on oct. 3 1878. entering the service of the great western railway as an enginecleaner, he rose rapidly and soon became a power in swindon (the g.w.r. headquarters) both as a trade unionist and in local government. by 1910 he had become president of the amalgamated society of railway servants and played a leading part in its reorganisation as the national union of railwaymen of which he was appointed gen- eral secretary after the great railway strike of r911. under him the n.u.r. became the leader in the policy of “ industrial ” or “all grades ” as against “ craft ” trade unionism. his sagacity and influence made the n.u.r. a dominant factor both in indus- try and the political world. mr thomas early saw that larger labour aspiration can be realised only through political action, and was an intrepid oppo- nent both of syndicalism and of communism. he was elected member for derby in 1910 and his services to industrial peace were recognised by his appointment to the privy council in 1917. he opposed conscription, refused to enter the coalition govt. and fought the 1918 election on ‘‘ no more war.” in the railway strike of t919 he won important concessions for the railwaymen who, before the war, had been miserably underpaid. his book, when labour rules, published in 1920, expounded a policy of nationalisation for railways and other essential instruments of production. as secretary for the colonies in 1924, he showed statesmanship in his handling of the irish and other specific issues and in his outlook on imperial problems. from the first mr. thomas was closely associated with the management of the british empire exhibition at wembley and on this subject he has written for this eucyvclopedia. thomsen, vilhelm ludvig peter (1842- ), danish philologist, was born jan. 25 1842 at copenhagen. he took his doctor’s degree in 1869 and in 1871 became a lecturer at the university of copenhagen, where from 1887-1916 he was pro- fessor of comparative philology. in 1876 he visited england and lectured at oxford university. thomsen came to be known as one of the most prominent linguists of modern times and pos- sessed an extensive and thorough knowledge of the various thomson, lord—-thrace classes of languages. in different linguistic fields he wrote works of very considerable importance. of his writings dealing with northern and east european languages may be mentioned den gotiske sprogklasscs indflydelse paa den finske (1860); beroringer mellem de fiiske og de baltiske sprog (1890); and the relations between ancient russia and scandinavia and the origin of the russian state (1877). in romance philology he solved the problem of softened consonants (1876); he was the first to ascertain the palatal law in the phonic system of the indo-european languages. in 1894 he deciphered the orkhon inscriptions from mongolia (inscriptions de porkhon dechiffrecs, 1894) etc., and made in 1899 important interpretations of etruscan and lycian texts, and in turcica (1916) he treated ancient turkic. thomsen’s complete articles appeared in 1919 in three volumes. he became the president of the royal danish scientific society in 1909. thomson, christopher birdwood, 1st baron (1875- ), british soldier and politician, was born april 13 1875. educated at cheltenham and the royal military academy, wool- wich, he served in the mashonaland campaign and in the south african war. from 1002-s he was instructor at the military engineering school at chatham. in 1909 he passed on to the staff college and in ro1t to the war office. during the world war he served as military attache and chief of the british military mis- sion in rumania (1915-6), and in palestine (t917) and was on the supreme war council in 1918. having attained the rank of brigadicr-general, he resigned from the service in 1920 as a pro- test against allied intervention in russia. he joined the labour party, and accompanied, as military expert, the commissions of enquiry dispatched by that body to ireland and to the ruhr; later, he visited russia. in 1922, and again in 1923, he stood for ' parliament inthe labour interest, but was unsuccessful. in 1924, he was appointed air minister in the first labour govt., with a seat in the cabinet, and raised to the peerage. a graceful and effective speaker, lord thomson also possessed marked literary gifts; he wrote old europe’s suicide (1922); victors and vanquished (1924); and esmarana (1926). thomson, john arthur (1861- ), british naturalist, was born at east lothian on july 8 1861, and was educated at the universitics of edinburgh, jena and berlin. he was, for a time, lecturer on zoology and biology at the school of medicine in edinburgh, and in 1899 he became regius professor of natural history at aberdcen university. apart from his purely zoological work, chiefly on alcyonarians, professor thomson did much, both by his lectures and his numerous attractive books and writings, to popularise biological science, and he was inde- fatigable in his efforts to correlate science and religion. ile made an extensive lecture tour in america in 1924. his publications include: outlines of zoology, 7th ed. (1920); intro- duction to science (1911); the wonder of life (1914); secrets of ant- mal life (1919); the sysiem of animate nature, gifford lectures (1920); science, old and new (1924); the new natural ffistory (1925); science and religion (1925) and many other books and papers on allied subjects. thomson, sir joseph john (1856- }, british physi- cist, was born dec. 18 1856 near manchester and eccducated at owen’s college, manchester, and at trinity college, cambridge, where he was elected a fellow in 1880 and became lecturer in phys- ics in 1883. in 1884 he was appointed cavendish professor in the university of cambridge and in tg19 research professor, holding in addition from 1905-18, the professorship of physics at the royal institution, london, and subsequently an honorary appointment. he became master of trinity college in 1918. he developed at cambridge a great research laboratory, which attracted numerous workers from many countries, and carried out there epoch-making investigations on the conduc- tion of electricity through gases, the determination of the charge and mass of the electron, and analysis by means of positive rays. he became f. r. s. in 1884, and was president in rors. he was knighted in 1908, and was the recipient of many british and for- eign awards and honours, including the royal and hughes medals of the royal society in 1894 and 1902 respectively, the hodgkins 705 medal of the smithsonian institute of washington in 1902, the nobel prize for physics 1906, the o. m. in 1912 and the franklin gold medal, 1923. during the world war he assisted various government departments in an advisory capacity. (see gases.) in addition to a large number of publications in the proceedings of the roval society and the philosophical magazine, he published a treatise on the motion of vortex rings (1883); the application of dynamics to physics and chemtstry (1888); recent researches in electricity and magnetism (1893); elements of the mathematical theory of electricity and magnetism (1895, 5th ed. 1921); the discharge of electricity through gases (1898); the conduction of electricity through gases (1903); rays of positive electricity and their application to chemical analysis (1913 2nd ed., 1922); the flectron in chemistry, five lectures delivered at the franklin institute, philadelphia (1923); and, with professor poynting, a number of general text-books on physics. thorndike, edward lee (1874- }, american psy- chologist, was born at williamsburg, mass., aug. 31 1874. he graduated at wesleyan university (a.b., 1895), proceeding later to harvard university (a.b., 1896) and columbia university (ph.d., 1898). he taught for a year in western reserve uni- versity and in 1899 became instructor in psychology at colum- bia university, where in 1904 he was appointed professor. his application of statistical methods to intelligence tests consti- tuted a notable advance in the field of psychology. ile wrote educational psychology (1903); mental and social measurements (1904); animal intelligence (1911); the original nature of man (1913); the psychology of learning (1914); psy- chology of arithmetic (1922); psychology of algebra (1923); and, in part, the measurement of intelligence (1926). thorndike, sybil (1885- ), british actress, was born at gainsborough, lincolnshire, and educated at the high schoo), rochester, when her father, rev. a. j. w. thorndike, was a canon of the cathedral. from 1903-7 she toured america in shakespearean repertory with ben greet. returning to england she became a member of miss horniman’s company at the gaiety theatre, manchester, 1908~9. her training in repertory stood her in good stead when, in 1914, she became attached to the “old vic” company in london. she remained there until 1978, and is said to have acted in every shakespearean play. her repu- tation as an actress was steadily growing, but it was not until 1919, when she appeared in a series of matinees at the holborn empire, in which she played the parts of hecuba in the trojan women and of candida, in mr. bernard shaw’s play of that name, that she attracted wide attention. henceforward her suc- cess was assured. among her principal parts were thai of jane clegg in mr. st. john ervine’s play, and joan of arc in mr. ber- nard shaw’s suizt joan. from 1920-2 she sustained a number of leading parts in grand guignol at the little theatre, london. in 1908 miss thorndike married mr. lewis thomas casson, with whom she had often appcared upon the stage, and who fre- quently acted as her producer. thornycroft, sir william hamo (1850-1925), british sculptor (see 26-881), died at oxford dec. 18 1925. thrace (see 26.885), a former turkish province, now divided between greece (western thrace) and turkey (eastern thrace). thrace was one of the three theatres of the first balkan war of 1912, when the bulgarians entered it and defeated the turks in the great battle of lule burgas, subsequently marching up to the ramparts of chatalja, where the armistice with the turks was signed. with the assistance of serbian troops the bulgarians took adrianople, and the treaty of london of may 30 1913 put back the frontier of european turkey to a line drawn from enos on the aegean to midia on the black sea. nearly all thrace had thus fallen to the share of bulgaria, but her quarrel with her allies over the spoils in macedonia led to the second balkan war of 1913, and the turks took the opportunity to recapture adrian- ople, to reoccupy western thrace and create the ‘* independent government of giimiiljina,” a mainly moslem district. the treaty of constantinople of sept. 29 1913 set back the turco- bulgarian frontier in thrace to the mouth of the river rezvaya on the black sea, considerably to the north of midia, and, while mak- ing the right branch of the maritsa the frontier on the aegean, so drew the line between those points as to include kirk kilisse and 776 adrianople within turkish thrace. but giimiiljina was restored to bulgaria, with the result that 14 moslem deputies of western thrace neld the balance of power in bulgaria and, under the influence of their compatriot talaat, helped to bring bulgaria over to the central empires. meanwhile the third treaty of bucharest fixed the greco- bulgarian frontier at the mouth of the mesta; thus the thracian coast from the mesta to the maritsa gave bulgaria her coveted out- let on the aegean. but the frontier cut the latter river and the mustafa-pasha (svilen) adrianople-dedcagach railway so that bul- garian trains had to traverse turkish territory before reaching their bulgarian port. the maritsa was consequently declared free to the transit of both states till they had made fresh lines on their own ter- ritories. the cession of this awkward bend in the railway to bul- garia in i915 was a further inducement to enter the war on the turkish side. thrace was not long left in peace, for the operations at the dardanelles brought her again within the war zone. the treaty of neuilly of 1919 again changed her boundaries. bulgaria was moved back from the thracian sea coast in favour of greece, which by article 27 of the treaty of sevres of 1920 obtained the lion’s share of thrace as far as ‘‘a point near the mouth of the biyuk dere \"' on the black sea, and ‘a point on the sea of marmara about one kilometre southwest of kalikratia ’’—in other words, up to the chatalja lines. thus the valuable tobacco plantations of xanthe, and the port of dedeagach (rechristened alexandroupolis) became greek. but the allies undertook to make the maritsa an international river and ‘' to ensure the economic outlet of bulgaria to the aegean ”’ by article 48 of the treaty of neuilly. this they effected—in theory—by “‘ the thracian treaty,” signed on the same day as that of sevres, which decreed, as a condition of the recognition of greek sovereignty over the former bulgarian territories in thrace, that bulgaria should have “ freedom of transit over the territories and in the ports assigned to greece in the present treaty,” that ‘in the port of dedeagach bulgaria will be accorded a lease in perpetuity, subject to determination by the league of nations, of a zone,” and that dedeagach be ‘‘ declared a port of international concern,” free to all members of the league. in practice, bulgaria has not availed herself of this provision, rejecting m. veniselos’ offer in 1922 of a lease of the port and preferring a corridor anc actual possession. the greek tenure of eastern thrace was brief. after the disaster in asia minor, article 2 of the second treaty of lausanne of july 24 1923 restored eastern thrace up to the maritsa to turkey, leaving west- ern thrace to greece. by conventions 3 and 6, on either side of these greco-turkish and bulgaro-turkish frontiers in thrace demili- tarised zones of about 30 km. were established and existing fortifica- tions ordered to be dismantled, and the moslem inhabitants of west- ern thrace were exempted from the obligatory exchange of popula- tions. thus thrace is at present divided between turkey, greece and bulgaria. a boundary questidn between greece and turkey arose later over an island at the estuary of the maritsa. economic conditions.—southwestern thrace, the most fertile portion of the country, has scarcely recovered from the damage inflicted upon it during the balkan wars of 1912~3. the maritsa is navigable up to adrianople by flat-bottomed boats, but the thracian ports are poor. railway communications are compli- cated by the unscientific frontier near adrianople, whereby the line from western europe to constantinople traverses a tiny strip of turkish territory, re-enters greece and then recrosses into turkey. like all territories which have been under turkish rule, thrace is in a primitive condition, but the economic loss of the eastern half has been specially felt, because that would have been a field of labour for the greek refugees. turkish thrace ts now ethnologically overwhelmingly turkish, while the greeks find the remaining moslems of the western half useful for the tobacco culture. the demilitarisation of the gallipoli peninsula by the lausanne treaty should spare thrace the spectacle of hostile armies. but the present situation (1926) may be regarded as provisional and artificial. bibliography.—british and foreign state papers, vol. 107, pp. 656, 658, 720 (1914); vol. 112, p. 781 (1919); vol. 113, pp. 479-485, 657, 751 (1920); a. antoniades, le developpement economique de la thrace (athens 1922); n. moschopoulos, la question de thrace (athens 1922); treaty series, no. 16, cmd. 1929 (1923). (w. ml.) throat: see ear, nose and throat, diseases of. thunder: see atmospheric electricity. thuringia (sce 26.901), a territory and free state (einheitts- staat thiiringen) of the german reich. its area is 4,541 sq. m. and the population (1926) 1,624,675. political history —on april 30 1920 the union of the terri- tories saxe-weimar-ejisenach, saxe-meiningen, saxe-altenburg, saxe-gotha, reuss, schwarzburg-rudolstadt and schwarzburg- throat—tibet sondershausen was recognised by a law of the german reich on the basis of article 18, section 2, of the constitution of the reich. this was a natural consequence of the disappearance of the small particularist dynasties which had been removed in these states, as elsewhere, by revolutionary methods in nov. 1918. an exception was schwarzburg-rudolstadt, where the republic was established by a law enacted conjointly by the prince and the diet. the two principalities of reuss had al- ready united in one democratic state of reuss. on the other hand, the personal union between coburg and gotha was dis- solved, saxe-coburg declaring for union with bavaria nov. 30 1919 (ratified by the reich april 30 1920). after the revolution all thuringian states (except gotha, where a sovict regime held sway for some months) instituted elections for constituent assemblies to vote new constitutions. meanwhile, however, the movement for union grew. all the states except saxe-meiningen and saxe-coburg concluded a preliminary “* treaty of commu- nity ” forming a kind of federated state with a single organ of legislation (volksrai) and of administration (staatsrat). saxe- meiningen subsequently joined this union, and on jan. 28 1920 the volksrat passed a law assuming the right to include within its competence the enactment of a constitution for the state of thuringia. on may t2 1920 the provisional constitution voted by the volksrat was promulgated and ratified with certain amendments on march 11 1921 by the newly elected landtag. constitution.—t huringia is a republic with parliamentary govern- ment. thedict consists of asingle chainber elected on a system of pro- portional representation. it can bedissolved by a popular vote ( volk- sentscheid). the peculiarity of the thuringian constitution is that the committees of the diet may call in experts to supplement their membership. the executive power is in the hands of the ministry, which is formed on the principle of equal colleagues (kollegzal- prinzip), and consists partly of members who hold office and partly’ of members who hold no office and who are designated state coun- cillors (staatsrdie). the members of the ministry are appointed by the diet. the president of the ministry is chosen by the ministry and is merely its chairman. the thuringian constitution does not provide for any president of the state. the legislative prerogatives of the diet are limited by the right of the people themselves to initiate legislation (volksbegehren) or vote by referendum on measures already passed. after the revolution the communists were in the majority and formed the government, but the elections of 1924 brought a reversal; the new government was formed by the bloc of non-socialist parties cordnungsbloch).. a ee a tibet (see 26.916), a country of central asia. estimated area 800,000 sq. miles. population estimated at 4,000,000. in feb. 1910 chinese troops entered lhasa. the dalai lama and his ministers fled to india, taking their seals of office with them. the govt. of china issued a proclamation deposing the dalai lama, but the tibetans refused to recognise this. in exile at darjeeling the tibetan govt. denied the chinese claim to suze- tainty over tibet and appealed for british intervention. the british govt., however, declined to dispute the authority of the de facto govt. in tibet. at the same time they reminded the chinese govt. of the necessity of respecting british treaty rights, and announced their intention of protecting nepal, bhutan and sikkim, should the necessity arise for doing so. china and tibet.—until the outbreak of the chinese revolution in rgr1z the chinese worked steadily to consolidate their position in tibet. but in nov. 1911, when the news of the revolution reached tibet, some of the chinese garrisons mutinied, and com- menced looting the tibetan villages. fighting followed, with the result that the tibetans overpowered the chinese troops in cen- tral tibet and deported them across the indian frontier. in june 1912, the dalai lama returned to his country. throughout eastern tibet the chinese were able to maintain most of their ground. in july 1912, a chinese force was again dispatched to tibet but failed to make much headway, and was withdrawn after representations had been made by great britain at peking to the effect that such action contravened the convention of 1906. at the end of 1912 russia concluded a convention with mon- golia. this was signed at urga, the mongolian capital. russia agreed to assist mongolia in preserving her autonomy against china, and received in return extensive economical and political tidal power privileges in that country. this convention was followed by what purported to be a treaty between mongolia and tibet, but the validity of this latter document is questionable. ‘towards the end of 1913 a russo-chinese treaty confirmed the russo- mongol convention. a futile conference-—during 1913 the chinese resumed hostilities and endeavoured also to negotiate with the tibetan government. the latter declined to meet any representatives from china unless a british representative were also present at the conference. accordingly, in oct. 10913, plenipotentiaries from the three countries assembled at simla to discuss and to define the political status of tibet. china was represented by mr. ivan chen, tibet by lenchen (a title denoting chief min- ister) shatra and great britain by lt. col. sir a. h. mcmahon. after six months’ discussion the three plenipotentiaries initialed a convention by which:— (a) chinese suzerainty over tibet was recognised. (b) tibet was divided into “ inner tibet,” the part nearer china, and ‘‘ outer tibet,” the part nearer india. the latter was to be autonomous, the former under a considerable measure of chinese control. (c) the chinese amban was to be re-established at lhasa with a suitable military escort. (7) a fresh trade treaty was negotiated between india and outer tibet. (e) the frontier between tibet and northeastern settled. india was the chinese govt. refused to ratify the convention, explaining that its sole objection was to the frontier between china and tibet as established by the convention. after the break-up of the conference the chinese and tibetan govts. agreed to suspend hostilities against each other pending a renewal of the negotiations. in 1917, however, fighting was tesumed, the chinese general on the frontier being apparent- ly responsible. in the campaign that followed the tibetans were victorious. driving the chinese out of the districts of mang- kam, traya and chamdo, they recaptured their territory as far east as the yangtze kiang. in july 1918 a truce was arranged by the british vice-consul, the tibetans retaining the lands which they had reconquered but advancing no further. the war and after—during the world war the govt. of tibet offered 1,000 tibetan soldiers to fight on the british side and further ordered that special services for the success of the british arms should be held from time to time in the leading monasteries throughout tibet. an event of some significance occurred about this time in the dispatch of four tibetan boys of the upper middle class to england, where they received, so far as the time at their disposal allowed, an english education. in 191g the chinese govt. at peking proposed a renewal of the negotiations abandoned in 1914, but subsequently withdrew their proposals, as they met with strong opposition from their own countrymen. early in 1920 a chinese mission visited lhasa and remained there four or five months, but left without coming to any settlement with the govt. of tibet. towards the close of 1920 mr. (afterwards sir) charles bell, the british representative in tibet, was dispatched to lhasa at the request of the tibetan govt., the first mission from any coun- try outside china to be invited to the tibetan capital, as a re- sult of the mission, which remained a year in lhusa, it was de- cided to afford the tibetan govt. such reasonable assistance in the settlement and development of their country as might be expected from a friendly neighbour more advanced than them- selves. the desire of tibet for closer co-operation with india was further shown by her request for the linking up of lhasa with the indian telegraph system. this was effected during the summer of 1922. the tibetan govt. are thus enabled to communicate with india and receive an answer the same day instead of waiting seven days for the reply. in 1926 the position of the sino-tibetan dispute was that tibet desired a settlement. but there is a strong body af public.opinion in china opposed to recognition of the standing which tibet claims, and, even if a settlement were reached with the chinese govt., the latter is not strong enough to impose it on kansu, 7/7 szechwan and yunnan, the three provinces that are chiefly con- cerned with tibet. since 1912 the tibetan govt. has maintained complete independence of china. her military strength appears to be slowly increasing, but is hampered by shortage of funds, for the country is poor, and a large share of the revenue is alienated to the priests and the nobility. trade, etc-—the trade between tibet and india is expanding slowly. minerals have not yet been discovered on such a scale as to warrant their being exploited commercially. during recent years a mint has been opened at lhasa. gold, silver and copper coins are minled. a limited number of currency notes have been put into circulation, the value of these ranging up to 50 tankas (=about 16 shillings). one of the four tibetan lads who came to england for education is understood to be starting a small hydroelectric scheme in lhasa. bra_iography.—sven hedin, trans-iimalava (1909-13); ekat kawaguchi, three years in tibet (1909); the blue book, further papers relating to tibet, cd. 5,240 (1910); sir f. younghusband, india and tihet (ag1o0); sven hedin, southern tibet (1916-22); r farrer, on the euves of the world (1917); the china year book (1919, 1921 and 1925); e. teichman, travels of a consular officer in eastern tibet (cambridge, 1922); f. kingdon ward, the afystery rivers of tibet (1923); sir c. bell, ‘‘ a year in lhasa,” geog. jour. (feb. 1926); tibet past and present (926). (c. a. b.) tidal power.—the idea of utilising the rise and fall of the tides for power purposes has long attracted the attention of in- ventors, and many ingenious schemes have been suggested. so far, however, the only practicable method is based on the use of one or more tidal basins, separated from the sea by dams or barrages, and of hydraulic turbines through which the water is passed on its way between basin and sea or between one basin and another. . . any simple tidal power scheme suffers from the disadvantages that the working head is both low and variable, not only from day to day but also over any one tide; and that the turbines cease to operate for a more or less extended period on each tide. more- over since this idle period depends on the time of high and low tide it gradually works around the clock, and will, at regular intervals, be included in the normal working day. while schemes of operation are feasible in which the idle period may be elim- inated this involves a large reduction of output per square mile of tidal basin area. even in such schemes, unless the working head and the output be limited to that available at the lowest neap tides there is still a large variation of output between springs and neaps. on the other hand, with such a limitation the power developed is only a small fraction of the total energy available, and the cost of the necessary engineering works per horse-power- year will be prohibitive except under exceptionally favourable circumstances. in order to obtain a continuous output or energy, or an output suitable for any ordinary industrial load, some storage system is necessary, unless the scheme is connected with some steam or inland water power station capable of equalising the supply at the idle periods and during the neap tides. storuge systems.—various storage systems have been sug- gested, such as electrical accumulators, electrically heated steam boilers, and those using compressed air. at present the most promising consists of an elevated storage reservoir supplied from pumps driven from the turbines at times of excess supply, and feeding a battery of secondary turbines. the method is, however, only possible where there is a suitable elevated site within reasonable distance of the tidal basin. types of schemes.— briefly outlined the more promising of the schemes of tidal power development are as follows:— (a) a single tidal basin is used, divided from the sea by a dam in which are placed the turbines. the basin is filled through sluices during the rising tide. at high tide these are closed. when the tide has fallen through about one-half its range, the turbine gates are opened and the turbines operate on a more or less constant head until low tide or slightly after. if a be the surface area of the basin in square fect; if 11 ft. be the tidal range; if a constant working head of h tt. be adopted; and if the turbines operate until low tide, the volume of water used during the falling tide will be a (h-h) cu. ft., and the energy available in the water will be 64 a(h-h) ft. ib. per tide. 778 this expression is a maximum when h = h—2, that is when the work- ing head is one-half the tidal range, and then equals 16 a h? ft. pound. | if a is in square miles, and if the efhciency of the turbines is 75 % the output in horsepower-hours per tide is given by 4 x 33000 x60 =a the cycle of operations is shown in fig. § where a b denotes the working period and c d the period of replenishment of the basin. the sine curve represents the level of the sca outside the basin. owing to the great variation in the rate of efflux of the water in this constant-head method of operation, the power output varices very largely during the falling tide. this variation may be reduced con- fig.4., schemes of tidal power development fic. 1.—single tidal basin, divided from sea by a dam in which are placed the turbines. fic. 2.—single tidal basin, with turbines operating on rising and falling tides. i'1c. 3.—two tidal basins, with turbines in dividing wall. fic. 4.—two tidal basins, with turbines installed in walls dividing the sea from each basin, siderably by allowing the turbines to operate on a more or less con- stant fall of level in the basin as shown by the straight full line a 33. by this method of operation the necessary turbine capacity for a given output may be grcatly reduced. by extending the working period beyond low tide, as indicated by the dotted line ae, a greater amount of energy may be developed per tide and the idle period is diminished, but at the expense of an appreciably greater variation in head. the most efficient combination of working pcriod and of working heads can only be determined by detailed examina- tion of the particular site, and with a knowledge of the exact form of the tidal curve. (b) a single tidal basin is used, with the turbines operating on both rising and falling tides. the cycle of operations is indicated in fig. 2. the working period per complete tide now extends from a to b and from c to d. slightly before low water, at b, the basin is tidal power emptied through sluice gates, and at d, a little before high water, the basin is filled through the sluice gates. with a working head equal to one-half the tidal range, the period of operation is approxi- mately 60° greater than in system (a) with operation down to low tide, and the work done per complete tide is some 60% greater. (c) two basins of approximately. equal areas are used, with turbines in the dividing wall. each basin communicates with the sea through suitable sluice gates. in one of these basins, called the upper, the water level is never allowed to fall below one-third of the tidal range, while in the lower basin the level is not allowed to rise above one-third of the tidal range. vhe working head then varies from 0-53 h to o-80 h, with a mean of approximately 0-66 h, and operation is continuous as indicated in fig. 3, which shows the cycle of operations. between a and 8b, the upper basin is filled from the sea through appropriate sluice gates, and the lower basin discharges into the sea from c to d. for a given total basin area and a given tidal range, the output is only about one-half that obtained in system (a) and one-third that obtained in system (6), so that except where the physical configuration of the site is particularly favourable the cost per horsepowcr is likely to prove very high. (7d) two tidal basins of approximately equal areas are used. turbines are installed in the walls dividing the sea from each basin. fig. 4 shows the cycle of operations. from a to b the upper basin discharges through its turbines into the sea. irom b to ie the sea enters the lower basin through its turbines. vyhe upper basin is filled from the sea through its sluice gates between © and d, and the lower basin is emptied through its sluice gates from f to g, the head varies from 0-25 i1 to 0-62 h, and the output is some 25% greater than in system (c), but the number of turbines required is much greater. it is possible to arrange in each of these systems that the head shall be maintained constant during any one working peri- od, but since this means that the working head is then limited to the minimum obtaining during that period, a loss of energy is involved, with a great additional cost of construction and com- plication in manipulation and with little cempensating advan- tage. for any scheme of development involving the use of a tidal estuary of such type as is found in the severn or dee, the cost of any of the multiple basin systems would appear to put them definitely out of court. a scheme involving operation only on a falling tide has the disadvantage that the output is only about 60% of the output theoretically possible with double-way operation. on the other hand the output per unit of turbine capacity 1s sensibly the same, while it enables a much more efficient type of turbine setting to be used, and enables the number of sluice gates to be halved. it has the further advantage, where applied to a navigable river, that the depth of water in the basin never falls below mean tide level or thereabouts, so that navigation above the barrage is improved. the scheme is essentially more simple than any one involving double-way operation. the severn scheme. up to the present (1926) no tidal scheme of any magnitude has been constructed. the possibilities of such an installation on the estuary of the severn are, however, now under consideration by a committee appointed by the british government. this would consist of a single tidal basin of about 25 sq. m. in area formed by a barrage probably in the neighbour- hood of sudbury, along with a storage reservoir some soo it. above sea level and about five miles away above the wye valley. single-way operation of the turbines is proposed. it is estimated that the scheme woukl be capable of developing some 500,000 h.p. over a 10 hour working day throughout the year. fundy bay scheme.—designs have also been prepared for a two-basin scheme for utilising the tides at passamaquoddy bay, an inlet of the bay of fundy in nova scotia, from which it is estimated that between 500,000 and 700,000 horsepower can be generated. | aber-vrach scheme—a scheme to which the french govern- ment is giving financial assistance is projected at aber-vrach on the coast of brittany, and appears likely to be undertaken almost immediately. for the tidal operated station a barrage 490 ft. long is to be constructed in the estuary. four turbines connected to synchronous generators are to be installed, each capable of developing 1,200 h.p., under the maximum head available at spring tides. the turbines are to operate both on the ebb and flow tides. this station will work in conjunction with an auxiliary water-power station some 4m. away on the river diouris. the tides river is to be dammed at this point, forming a fresh water reservoir from which turbines having a maximum capacity of 2,700 h.p. are to be supplied. electrically driven centrifugal pumps of a capacity of 3,200 h.p. will also be installed. during the idle periods of the tidal station, and during neap tides, the river plant will be used. as the tidal turbines come into operation the river plant will be shut down and finally when the tidal power becomes in excess of the demand the alternators at the river plant will be run as motors to operate the pumps, which lift water from the lower to the upper side of the river dam. it is anticipated that the combined plant will make it possible to maintain 2 continuous output having a maximum of 3,200 ii.p. and a minimum of 1,600 horsepower. bibliography.—a. m. a. struben, tidal power (1921); a. h. gibson, i ydro-electric engineering, vol. 2 (1922); n. davey, siudies in tidal power (1923). (a. h. gr.) tides (sce 26.938).—during the present century there has been a marked increase in the interest taken in tides. observation.—the observation of coastal tides by means of automatic gauges has been continued in most countries, but comparatively little has yet been done in the measurement of off-shore elevations. a number of attempts have been made to construct a seli-registering gauge which, when placed on the bot- tom of the sea, will give a continuous pressure-time record. from such a record it is of course easy to pass to an elevation- time relation. the gauge which appears to have met with most success is that of l. fave, of the french hydrographic depart- ment. the continuous measurement of currents has been con- tinued, though not to the extent which the importance of the work warrants. owing chiefly to the trouble of keeping a meter fixed relatively to the sea-bottom the accurate measurement of currents is attended with considerable difficulty. for the valuable series of observations taken in the north sea much credit is due to the international council for the exploration of the sea, which has its bureau at copenhagen. harmonic analysis—in 1920 j. proudman wrote for the british association a report on work in the british empire of harmonic analysis, and pointed out that much remained to be done on the subject. the harmonic constants did not represent completely the records analysed; for certain british stations the discrepancy reached a semidiurnal range of one foot and a quar- ter diurnal range of one foot. also, the numbers obtained for the same constant from different records showed considerable varia- tion. since then much attention has been given to the subject, notably by a. t. doodson, of the liverpool tidal institute, which was established in 1919. he has made a new development of the generating potential, working to a much higher order of approximation than g. h. darwin, and making it truly harmonic instead of grouping together a number of terms to form a slowly varying constituent. he found that there is a very large number of other terms which, while certainly smaller than those of darwin, are not very much smaller and in their aggregate may be important. in other words, the convergence of the series of con- stituents is not so rapid as had been assumed. a corresponding state of affairs exists with regard to over tides and compound tides. for certain british stations doodson has found it possible to obtain a practically complete representation of the quarter diurnal tides, but it involves many more harmonic constituents than had previously been sought for by the customary methods. he has also been able to account for part of the variation in the numbers obtained for harmonic constants. p. schureman, of the united states coast and geodetic survey, has published a list of harmonic constants for 840 stations. tide tadles can still not be regarded as completely satisfactory even for such practical purposes as docking large vessels and navigating over shoals. the main deficiency appears to be one of analysis of records. geographical distribution —observation has now provided us with a good knowledge of the principal tidal constituents along all the coasts of the world, but very little is yet known for cer- tain as to their distribution © over the oceans. general theory indicates that somew here in the oceans there will be “ amphi- dromic points,” i.¢e., points at which there is no rise and fall of the 779 water and from which the cotidal lines radiate. a knowledge of the position of these points would summarise a large amount of information, and consequently much attention is paid to them. in 1920 r. sterneck prepared world-charts for the chief semi- diurnal and diurnal constituents, based on all available data, but they must be regarded as largely hypothetical. the charts differ in many important respects from those of r. a. harris, though there is much similarity for the north atlantic. where tidal currents have been well observed, funclamental mechanical principles lead to much information regarding the tidal eleva- tions. an example of this is afforded by the north sea, the principal constituent of the tides of which may now be regarded as well known over the whole area. the investigation has been carried out since 1920, and so far is almost entirely restricted to the north sea. dynamical theory.—the tides of any body of water are dynamically determinate when cither the elevations or the normal currents are known along the sections which are taken as dividing the body from other waters. in explaining the tides of any particular sea or ocean, it is therefore necessary to assume either from observation or from other theory the tidal conditions in the water immediately neighbouring. the detailed explana- tion, on dynamical principles, of observed tides has so far been restricted to the elongated basins of narrow seas, channels and gulfs. the work is due chiefly to a. defant and r. sterneck and has all been carried out since 1910. it rests on the principle that for such basins the tidal currents are non-rotating and parallel to the general direction of the basin. in these circumstances the motion of the water may be regarded as a longitudinal oscillation with an oscillating transverse surface-gradient sustained by the currents in virtue of the earth’s rotation. the differential equa- tions are constructed after the manner introduced by g. chrystal for the seiches of elongated lakes, and are then solved by numer- ical step-by-step methods. applications have been made to the tides of the red sea, the persian gulf, the english channel, the trish sea and the adriatic sea. when the transverse currents cannot be neglected the theory presents much greater difficulty. even for the north sea a complete detailed dynamical explana- tion has not yet been given, though it is possible to give a qualita- tive one. in ro11 r. witting proposed an explanation of the baltic tides, and later r. sterneck proposed explanations of those of the mediterranean and black seas. their methods are largely those which apply to narrow seas, except that they are used transversely as well as longitudinally. no generally accepted de- tailecl explanation of the tides of the great oceans has yet been given, though a. defant has recently made an attempt for the atlantic and arctic basins. as regards the tidal dynamics of geometrically simple bodies of water it is convenient 10 consider separately closed and open basins. of the former the only cases which had yielded to mathematical treatment up to ro14 were those of a flat circular sea whose depth is a function only of the distance from the centre, and an ocean covering the whole globe, with the depth a function only of the latitude. the details for polar and zonal basins of uniform depth were worked out by g. r. goldsbrough in ror4, while the solution for a flat rectangular sea of uniform depth was given by g. i. taylor in 1920. for open basins the most impor- tant contribution is g. i. taylor’s solution (1920) for the tides in a, rectangular gulf of uniform depth. when modified to allow for friction the results provide a first approximation to an explana- tion of the tides of the north sea. at a later date j. proudman investigated the tides of a channel whose section is uniform along the length but of varying depth from side to side, obtaining results which indicate the degree of error in the assumption of no transverse current in narrow seas. other parts of the dynamical theory which have undergone development relate to the effects of capes, bays and islands on local tides, to slowly rotating seas and oceans and to limiting forms of long period tides. in the last connection it should be mentioned that there is an erroneous statement in 26-958; viz., that continental barvicrs have the same effect as that attributed by laplace to friction. that this is not necessarily the case has been emphasised by e. fichot. 780 two attempts have been made to bring some of the latest methods of pure mathematics to bear on the general problem. in 1910 h. poincare transformed the dynamical equations from the differential to the integral form. the theory of integral equations has grown up almost entirely since 1900; its results are perfectly general, and are stated explicitly in terms of direct operations. but in the case of tidal problems the arithmetical labour necessary to carry out these operations is so prodigious as to prove quite prohibitive even for the reproduction of known solutions. nevertheless, the theory is valuable for the estab- lishment of existences, and in 1923 was further developed by g. bertrand. in 1917 j. proudman specified the tidal state of an ocean by means of an infinite number of co-ordinates of the lagrangian type, and then transformed the differential equations into an infinite set of linear algebraic equations. friction —if tidal motion were everywhere non-turbulent the amount of friction in the tides would be quite insufficient to account for the outstanding discrepancy between theory and ob- servation in the motion of the moon. but tidal currents in shallow seas are undoubtedly turbulent, and though this has long been recognised it was left for g. i. taylor in 1920 to make a numerical estimate of the associated dissipation of energy. h. jeffreys concludes that the total amount of friction is just sufficient to account for the discrepancy mentioned. he takes the chief contributing areas to be behring sea, the yellow sea, malacca strait and the n.w. passage. assuming the magnitude of the ocean tides to be of the order given by the equilibrium theory, jeffreys calculates that the total energy at any time pres- ent in the oceans is only equal to that dissipated by friction in about two days. bibliography.—h. poincare, lecons de mecanique celeste, vol. 3 (1907-10); a. defant, aan, d. itydrographie, vol. 39, 42, 50-52 (1911-24); r. wilting, fenanita, vol. 29, helsingfors (1911-2); j. proudman, london, math. soc. proc., ser. 2, vol. 12-14 and 18 (1912-8); r. sterneck, sitsungsber, akad. wissensch., wien (1913-5, 1920, 1922); g. r. goldsbrough, lexdon afath. soc. proc., ser. 2, vol. 14 (1914); a. defant, denksch. akad. wiss., wien, vol. 96 (1919); l. fave, ann. ll ydrographigques (1919); r. sterneck, denksch. akad. wiss., wien, vol. 96 (1919); g. ‘vt. taylor, roy. soc. pah. trans., vol, 220 (1919); p. schureman, u.s. coast survey, spee. pub., no. 98; a. defant, sitzungsb. akad. wiss., wien, vol. 129 (1920); hl. jeffreys, roy. soc. phil. trans., vol. 221 (1920); j. proudman, brif. assn. rep. (1920); g. t. taylor, london math. soc, proc., ser. 2, vol. 20 (1920); a. t. doodson, brit. assn. rep. (1921); proc. roy. soc., vol. 100 (1921-2); r. sterneck, ann. d. ifydrographie, vol. 50 (1922); g. bertrand, ann. ecole normale superieure, vol. 40 (1923); h, jetfreys, nafure, vol. 112 (1923); a. t. doodson, roy. see. phil. trans., vol. 224 (1924); j. proudman, phil. afag., vol. 49 (925). tientsin, china (see 26.963), with a population estimated variously at from one to two millions (including 683 british in 1925), is now the leading port of northern china and the prin- cipal outlet for the produce of four provinces. the trade of the port has grown rapidly, particularly with the united states and increased 100% between 1917 and 1923. commerce in eggs, carpets and marmot skins has developed. till 1920 the harbour was closed each winter by ice, but in that year three powerful ice-breakers were installed. tientsin handles a third as much trade as shanghai. in 1925 the authorities of the seven concessions were reclaim- ing land within their limits to cope with the need for houses and offices. the municipal services are very efficient, and the streets of the concessions are in good condition. a large electric light company started work in 1912. tientsin is an important railway centre, with a line to pukow and a station on the pekin- mukden line. a distributing, not an industrial, centre, it has a number of cotton mills, and distilling and salt-evaporation are large local industries. the concessions have been rapidly de- veloped. the former german and austrian concessions were taken over by the chinese authorities in 1917 and the two british concessions were amalgamated in 1918. the disastrous floods of 1917, when the grand canal burst its banks, carried away the main railway line to pukow and flooded the concessions, led to the formation of a commission to consider the problem of the chih-li river. an outer dike at tientsin, a cutting which tien tsin—tin shortens the course of the hai-ho and does away with some difficult bends, and an outlet for the machang channel have been made. other plans were considered in 1924, when further severe floods occurred. in 1925 the banks of the grand canal were strengthened. . tilak, bal gangadhar (1856-1920), indian nationalist leader, a chitpavan brahmin, was born at ratnagiri july 23 1856. at an early age he took the lead in providing education in poona under indian direction. in 1890 he was proprietor and editor of two weekly papers, afahratta, printed in english, and kesari (lion), printed in mahratti, which organs he used for anti-government propaganda. his violent condemnation in 1897 of the plague prevention regulations resulted in his being con- victed for sedition and sentenced to 18 months’ imprisonment. for the same offence he was sentenced in 1908 to six years’ trans- portation, subsequently commuted to simple imprisonment in mandalay. after his release he took an active part in the home- rule campaign, and secured for his party the control of the na- tional congress. he died in bombay on aug. 1 1920. his paper on the the orton, or researches into the antiquities of the vedas, read at the international congress of orientalists in london 1892 (published at poona 1893), expounded a theory of extremely re- mote aryan origins, which has not been accepted by other schol- ars. ilis formative part in the cult of indian unrest is shown in thereport of the rowlatt sedition committee (1918). his speeches are collected in lekamanaya b.g. tiluk (2nd ed. madras, 1920) timber: sce forestry; natural resources, conservation of. time: see space-time. time sales.—the second of the factors which played a great part in expanding the market for motor cars was the prac- tice of selling under the time-payment plan. for along time the automobile business was conducted on a cash basis. the pur- chaser made a deposit of from 20 to 30% at the time of plac- ing his order, and paid the balance upon delivery. no diff- culty was experienced in enforcing these terms, because the demand for cars ran ahead of the capacity of the factories to produce. gradually, however, production caught up with the demand, and it then became necessary to create a market among those classes of the population which generally are not well supplied with ready money. under the time payment plan, introduced to this end, the purchaser makes an initial payment of perhaps 334°4 when recciving his car, and the re- mainder is paid in monthly or weekly installments. see in- stallment selling.",
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