ILLINOIS

the population of illinois according to the u.s. census of 1920 was 6,485,280, as compared with 5,638,591 in 1910 and 4,821,550 in tg00. the rate of increase 1910-20 was 15% as against 14-9% for the whole united states and as against 16-9 °% for the state in the preceding decade. the population as of july 1 1926 was estimated to be 7,202,983. the increase of 1910-20 was urban, the rural population con- tinuing to decline. in 1920 the percentage of urban population in towns and cities of 2,500 or over was 67:9 % and 41:7 °% of the total population lived in the city of chicago. in 1920, 52:5 % of the state’s population was in cities greater than 25,000. popula- tion in villages of less than 2,500 declined from 12°%% in 1910 to 10o:s°% in 1920. purely rural population fell from 26-4% in 1gio to 21°6% in 1920. population of cities of over 40,000 at : population, population] increase | estimate city 1910 1920 a 1925 chicago . 2,185,283 | 2,701,705 23°6 | 2,995,239 cicero 14,557 44,995 | 209:1 62,238 pecatur 31,140 43,818 40°7 50,359 east st. louis 58,547 66,767 14:0 71,423 peoria. 66,950 76,121 1307 81,564 rockford 45,401 65,051 44:6 76,462 springfield 51,678 59,183 14°5 63,923 agriculture —while the census of manufactures shows i]linois to be an industrial rather than an agricultural state, there has been no absolute decline in her agriculture. according to the census of 1920 illinois was second only to iowa among the states in agricultural importance. based on crop values, in 1923, texas was first, iowa second, and illinois third, with farm crops amounting to $459,509,000. cereals are still the main crop and maize is the leading cereal. the largest crop was that of 1917 when 418,000,000 bu. were produced from 11,000,000 acres. in 1923 the crop of 337,000,000 bu. was a slight increase over the years immediately preceding. in 1923, 62,506,000 bu. of wheat were produced, grown on 3,479,000 acres. the production of oats has declined, but in 1923 with a harvest of 135,100,000 bu. from 3,860,000 ac. she took third place in the united states. in 1923 hinois ranked seventh in the production of barley and rye, pro- ducing 3°33% of the barley and 5.56% of the rye grown in the united states. in livestock, illinois, jan. 1 1923, with 1,125,000 milch cows, ranked fourth among the states; and in other cattle, numbering 1,477,000, ranked sixth. in number of swine, 4,460,000 and the number of horses, 1,277,000, h}inois ranked second only to iowa. manufactures—in the value of manufactures, illinois, in 1923, ranked fourth among the states. in 1919 the total value of her manufactured products was $3,366,452,969. in 109023 the total value had risen to $5,041,510,455. manufactures employed 645,433 wwage-earners, working in 14,348 establishments. the ten most important industrics with the values of their respec- tive products in that year are as follows:— manufactured products, illinois, 1023 slaughtering and meat packing (wholesale) foundry and machine shops . ’ ; jron and steel, steel works and rolling mills electrical machinery and supplies clothing, men’s ; ; . cars, steam road (not back in repair shop) printing and publishing, book and job printing, publishing, newpaper, ctc. cars, and general construction, steam ; bread, and other bakery products ; ‘ . $606, 320,553 275,955,047 213,671,552 211,366,206 186,683,333 159,304,227 138,227,215 i 32,285,355 113,604,362 105,289,516 the tendency in manutacturing was toward large-scale pro- duction and corporate ownership. of the 18,593 establishments in the state in 1919, the 799 producing $1,000,000 or over turned out some 75% of the products. in these industries 389,686 wage- carners were employed. chicago, with its tributary manufac- turing suburbs of maywood, harvey, cicero, blue island, chicago heights, and, in indiana, hammond and gary, is the great- est manufacturing centre of the state. a lesser manufacturing centre has grown up in the net of railways that centre at st. louis, collinsville, granite city and edwardsville. the third centre 408 is formed by moline and rock island with davenport, iowa. joliet and east st. louis were second and third respectively to chicago in the value of products in 1919. manufactures in chi- cago, are generally diversified. the same is usually true in the smaller centres, although a few cities are noted for their special products. thus, rockford is best known for its furniture manu- factures, kewanee for boilers, elgin for watches, moline for farm implements and automobiles. minerals.—in mining and allied interests illinois occupies an important position. coal constitutes her leading production. during 1924 67,880,000 short tons were mined, a total exceeded only by pennsylvania and by west virginia. the value of her petroleum production in that year was$14,200,000. limestone, sandstone, fluorspar, lead and zinc are the other leading products. communications.—for transportation, illinois relies chiefly on its steam railways. with 12,046 m. of main line she was in 1924 second only to texas. for over 30 years little new main-line road has been built. the important extension has been in double- tracking and improvement of the right-of-way and terminals. the field of passenger and light freight and coal transport, since 1900, has been invaded by the electric lines, which by 1924 operated 3,555 m. of track. the illinois traction system oper- ates a ramification of electric lines across the state from danville to east st. louis and radiating throughout central illinois; on certain runs it operates sleeping and parlour cars. illinois’ most important water transportation system is that of the great lakes. receipts of grain at chicago by lake have steadily declined of late years, although the lakes are still the usual route for shipment of wheat to eastern points. flour shipments by lake are comparatively insignificant, an important fact in view of the increasing quantity of grain milled at chicago. iron ore is still shipped to chicago and south chicago by way of the great lakes. in 1900 the sanitary district channel was opened, providing a waterway with a depth of 20 ft. for navigation be- tween chicago and lockport. but from lockport to utica, on the illinois river, a distance of 62 m., there was no adequate means of water transportation. a legislative act of r919 ac- tively supported by gov. frank o. lowden provided for the issue of bonds to the amount of $20,000,000 for the construc- tion of an eight-foot channel, “‘ the illinois waterway,”’ con- necting the points mentioned. little actual progress had up to 1925 been made towards carrying out this project for the lakes- to-the-guli water route. the improvement of the roads in the state of illinois has in recent years been given marked attention. <a state highway commission was created in 1905, various laws facilitating local road improvement were passed, and in 1914 state appropriations for hard roads were made from the proceeds of automobile licence fees. actual construction was begun in 1ory. acts of congress of 1916 and 19109, apportioning federal aid in behalf of roads, allotted to illinois $3,300,000 and $8,700,000 respec- tively. the question of issuing $60,000,000 in bonds based on automobile license fees for the construction of 4,800 m. of ard roads was sulmitted to the voters of the state in nov. 1918 and was approved by them. construction of roads under federal aid and by means of this bond issue has been going forward. in 1922 722 m. were completed and over 1,000 m. in 1923. the state legislature in 1923 authorised a bond issue of $100,000,000, providing for the continuance of a state-wide system of hard- surface roads, and this legislation was approved by the people at the general election of 1924. banking.—the northern part of illinois lies in the 7th federal reserve district and the southern part in the 8th, with head- quarters respectively in chicago and st. louis. in 1925 there were sor national banks in illinois with aggregate capital stock of $94,480,000, aggregate surplus of $63,265,000 and total re- sources of $1,701,448,000. of these banks 32 are located in chicago, having resources amounting to $1,103,339,000. side by side with the national banks is the system of state banks created by the act of 1887, and operating under the supervision of the auditor of public accounts. in 1925 there were 1,396 illinois state banks with a total capital of $160,240,000, and aggregate resources of $2,682,196,000. of the state banks 176 are in chi- cago, having resources amounting to $1,926,594,000. government.—despite the difficulty of changing the organic law, in the period 1910-25 there were far-reaching changes in the organisation of the machinery for government. under the con- stitution of 1870 an amendment must be initiated by two-thirds of both houses in the general assembly and approved by a majority of all persons voting at the next election. further, ina session an amendment to but one article can be proposed, and no two amendments to any article can be offered within four years. revision of the constitution by amendment, therefore, proved too difficult, and in 1917 the general assembly voted to submit to the people the question of a constitutional convention, which was approved at the election of nov. 1918. accordingly, in 1919 an act was passed for a convention to meet jan. 6 1920. dif- ficulties arose over chicago’s representation in the general assembly, and in dec. 1920 the convention adjourned with its work unfinished to meet in sept. 1921. sessions were held at intervals until june 28 1922 when the constitution was adopted for submission to the people for ratification at a special election 1o be held sept. 12. the new constitution, in this election, was defeated by a decisive majority. changes in the state’s system of dppomenients have been effected. first, in time, was the extension, by the act of 1911, of the civil-service system, to the greater part of the state’s em- ployees. civil service now covers all state appointees except those appointed by the governor and confirmed by the senate, the scientific and academic staff of the university of illinois and the normal schools, and a few others. all examinations are com- petitive, although for some scientific posts ‘‘ unassembled ex- aminations ” are given which consist of questions as to training and experience. by an amendment of 1917 all appointees may be removed by the appointing authority, but are allowed an appeal to the state civil service commission on allegation that the removal is due to race, politics or religion. reorganisation of governmental machinery was begun in 1909 with the abolition of separate boards for the various state charitable institutions and the establishment of one central board of control possessing also certain powers over private charitable institutions. in addi- tion to this board a supervisory state charities commission was created. there remained, however, over one hundred state boards, bureaus and offices, paid and unpaid, created to execute various acts and to supervise various state institutions. the result was disorder and waste,’ a reorganisation recommended by a committce in 1914 was in great part adopted in the state consolidation act of 1917. this act necessarily left untouched the constitutional offices, secretary of state, auditor of public accounts, treasurcr, attorney-general and superintendent of public instruction, but set up in addition to them nine depart- ments—finance, agriculture, labor, mines and mincrals, public works and buildings, public welfare, public health trade and commerce, registration and education. the heads of these various departments, who are appointed by the governor and senate, have acted as a cabinct for the governor. llinois ratified the eighteenth (prohibition) federal constitutional amendment jan. 14 1910. public finance—expenditures authorised by the legislature for the biennium 1925-7 amounted to nearly $300,000,000. of the appropriations for 1925-7, $131,000,c0oo was for the con- tinuance of the hard-roads plan. it was anticipated that $35,- 000,000 of this amount would be supplied from money received by the state for automobile licences, while the remainder would come from the sale of $100,000,000 in bonds, the issue of which was approved by the people at the nov. election of 1924. among other more important items of appropriation were: public welfare dept. including state charitable, penal and reformatory institutions, $28,979,000; omnibus bill, $23,718,000; state treasurer, retirement of and interest on bonds, $23,575,000; public schools, $16,223,000; university of illinois, $10,620,000; state normal schools, five in number, $3,150,000; agricultural dept. $2,691,000; health department, $1,041,000. illuminating engineering education —in 1924 there were enrolled in the elementary schools of illinois 563,614 boys and 534,684 girls. in the state high schools there were 106,735 boys and 111,005 girls. this represents an increase of 113-76% in the number of high school pupils during a period of ten years. in addition to the public schools there were, in 1924, 960 private schools with 195,552 pupils. the total number of teachers in the elementary schools in 1924 was 42,865. in that year there were 9,117 high school teachers. the net expenditure, including new grounds and buildings and payments of bonded indebtedness with interest in 1922 was $103,375.359. of this amount, $79,126,323 was spent on current expenses, $20,386,043 for new grounds, build- ings and equipment, $2,224,466 for canccllation of bonded indebtedness, and $1,638,627 for interest on bonds. the salaries paid to teachers were comparatively low. the average salary for men was $1,679; for women, $1,449. a notable development in the public educational system was the growth in the number of township high schools, and the number of community high schools following the legislation of 1917. under the township high-school! law some 200 high schools were organised. acts of 1913 and ro15 directed the payment by local school authorities of tuition for children who wished to attend high school else- where when there was none in their districl. during one year, 1920, 167 community high schools were organised, and at the end of 1922 there were 465 such schools in the state. at the close of the year 1924 the number had risen to 915. with the rapid growth in the numbers of high school graduates (24,507 in 1924) there was a corresponding increase in the enrolment in the uni- versitics and colleges of the state. the attendance at the university of chicago, 1923-4, was 13,357; university of illinois 11,083; and northwestern university, 9,150. in addition, there are in the state 29 colleges of recognised standing and 6 teachers’ colleges. located in chicago are four class a medical schools, two class a law schools, three class a dental schools and nine schools of theology. recent political history—in 1912, as a result of the progres- sive secession, the republican party for the first time in 16 ycars lost control of the statc, the democratic presidential elector winning by a vote of 405,038, as against 386,478 for the pro- gressives and 253,593 for the republicans. the democratic state ticket headed by kdward f. dunne was elected by a some- what larger plurality over gov. charles s. deneen, republican, and frank h. funk, progressive. the democrats, however, did not control the general assembly on joint ballot, and had to compromise with the republicans on the election of one demo- cratic senator, james hamilton lewis, and one republican, lawrence y. sherman, the latter to fill an unexpired term to 1915. by ror4 the normal republican majority in the state reasserted itself, the popular vote for scnator in that year being l. y. sherman, republican, 390,661; roger sullivan, democrat, 373,403; raymond robins, progressive, 203,027. [president woodrow wilson lost the state in the presidential election of 1916 by 160,000 votes. frank o. lowden, republican, was elected governor over edward f. dunne. in spite of the appeal for the support of the administration of woodrow wilson which was made on patriotic'grounds, only five democratic congressmen were elected by the state in 1918, and medill mccormick, republican, defeated j. h. lewis, demo- crat, for senator by 53,024 votes. in 1920, after an extremely bitter primary fight in the republican party, len small was nominated for the governorship over john j. oglesby. in the election, republican state and national tickets swept the state by overwhelming majorities. in the primary clection for gover- nor, april 8 1924, gov. len small received a plurality of 59,920 votes over thurlow g. essington, and norman l. jones was nominated by the democratic party. charles $. deneen defeated senator medill mccormick for nomination for the u.s. senate on the republican ticket. governor small made his campaign chiefly on his record for the promotion of the construc- tion of hard roads. the road-bond issue of $100,000,000 for this purpose was voted on at the same time. gov. small was re-elected with a plurality of 345,028 votes over the democratic 409 nominee, dencen was elected to the u.s. senate. the governors of illinois after 1905 were: charles 5. deneen, rep., 1905-13; edward f. dunne, dem., 1913-7; frank o. lowden, kep., 1917-21; len small, rep., 1921-5, and 1925- see, in addition to the books listed in 14.311, centenaial history of illinois (5 vol., published by the state, 1918-20) and -later volumes of the t/linois historical collections. (j. a. j. illuminating engineering, term now used to denote all applications of natural and artificial ight in the service of man- kind. progress in great britain since 1910 is largely the result of the formation (in 1909) of the illuminating engineering so- ciety, in which makers of lamps and lighting appliances and users of light co-operate; all illuminants are represented and all aspects of the subject, economic, hygienic and artistic are considered. a similar body, the pioneer in this field, has been in existence in the united states since 1906, and corresponding bodies have been formed in germany (1913), austria and hungary (1925) and japan (1915). in germany two additional societies operat- ing in karlsruhe and in the rhine-westphalia district have also been created. attention has been paid to illumination at many international congresses, thus promoting the exchange of views between experts in different countries. the re-organisation of the inter- national photometric commission, founded in 1900, as the inter- national illumination commission, was stopped by the world war, but a fresh start was made in 1921, and the jeading coun- tries are now represented with national committees for the respective countries.! | much has been done towards standardisation and agreement on common principles. definitions of the main photometric quantities have been adopted, and a more extended series of definitions, symbols, etc., framed, while sub-committees to deal with lighting legislation, automobile headlights, etc., have been formed. at the session held in geneva in 1924 further activities were initiated and the commission is now extending its work to deal with various practical problems. the international candle—a noteworthy step, dating from 1909, has been the agreement between france, the united states and great britain and, recently, also russia, on an international candle so that the same unit of light is now in use in all four countries; but in germany and some other countries the hefner candle (equal to o-g international candle) is still in use. preser- vation of the unit of light is now effected by the exchange of specially prepared electric lamp-standards between the official jaboratories in the countries concerned. meantime experiments are being made with a view to evolving an absolute standard of light, e.g., one basecl on the maintenance of a “ black body ” at a specified temperature. in the united states the standard is the /umen or the amount of light that would fall on a surface so placed that all its parts are at a distance of one foot from a light source of one candle power. technical progress.—vrogress in illuminants has kept pace with this advance on the scientific side. electric lamps, fila- ment and arc, have been developed (see electric lighting). in the field of gas lighting there has been steady progress in design, one instance being the smaller and more compact forms of high-pressure gas lamps, now rated to give 60 candles per cu. ft. of gas consumed. in low-pressure gas lighting the use of superheated clusters of inverted mantles has made possible a gain in efficiency estimated at 30%. the distribution of the light from a number of smaller mantles is considered an advan- tage, and the smaller types of mantles are the most durable. cluster-lamps giving up to 2,000 c.p. are now available. theory of radiation.—researches into the theory of radiation and the principles underlying illuminants provide a clearer understanding of the luminous efficiency theoretically obtain- able. thus a light source yielding visible white ight and no non-luminous vibrations would operate at approximately 26 c.p. per watt, whilst if the ight were confined to the most efficient yellow-green section of the spectrum as much as 60 c.p. per 1sce j. w. t, walsh, ‘international co-ordination in ilumination,” trans. first world power congress, vol. 3 (wembley, 1924). alo watt might be obtained. but in the case of new illuminants efficiency is not the only consideration; such special qualities as the colour of the light (as in the neon lamps) or the nature of the supplementary invisible radiation (as in the quartz tube mercury vapour lamps) may be of even greater importance. reflectors, etc—the design of shades, globes and reflectors for use with lamps has assumed great importance. by suitable. design of a reflector the distribution of light from a source may be altered with wide limits. thus extensive, intensive and focus- ing forms of reflectors yielding standard curves of light distribu- tion have been designed, and corresponding rules for height and spacing, designed to give even illumination on the working plane have been derived. in most cases a shade or reflector is designed to direct most of the light downwards, where it is chiefly neecled. but other cases occur, for example in shop window lighting and the illumination of large posters, etc., where reflectors are so designed and spaced as to yield an illumination over an extensive vertical area. glare prevention.—another function of shades and reflectors is to screen the actual source of light from the eye. even when only vacuum metal filament electric lamps were available the glare from exposed filaments irritated the eye and prevented it from registering the full effect of the illumination provided. in the case of the gas-filled lamps, with their very much brighter filaments, the need for scientific screening ts yet more evident. hence in the leading stores concealed lighting of show-windows, with the light thrown on the goods but the sources concealed from the eyes of observers, is coming to be regarded as the correct method; and it is only in the smaller shops that exposed sources of light are still too frequent. a special instance of a concentrating reflector is to be found in the “ floodlighting ” units, consisting of an incandescent lamp with a special ‘“‘ bunched ”’ filament at the focus of a parabolic mirror. such units are miniature searchlights and are now being used to illuminate the facades of buildings. it is possible to limit the angle of dispersion to about 15° and with a 500 watt lamp a beam with a candle power exceeding 300,000 has been obtained. with the searchlight proper, using an arc, the dimen- sions of the source of light can be reduced to much smaller dimensions, and a beam of many millions of candle power attained. searchlights—a notable advance during the war was the design of searchlights using specially cooled electrodes leading to a yet smaller and more brilliant source and corresponding greater concentration. the cooling has been effected by two distinct methods, a blast of air and a spray of alcohol; in both cases a very substantial increase in beam-candle power for a given current consumption was obtained.’ the brightness of the crater in such cases has been estimated at 200,000-300,000 candles per sq. in., as compared with 85,000 ¢.p. per sq. in., in the case of the ordinary searchlight. in germany, lummer, working with an arc operating in a chamber under an air-pressure of 22 atmospheres, is said to have attained the enormous bright- ness of 1,500,000 candles per sq. in. but this method has appar- ently not yet reached a practical stage.? coloured light—an apparatus capable of projecting pure spectrum colours on the stage, which is in effect a giant spectro- scope, has been designed. by the mutochrome projector, a series of superimposed patterns can be projected on the screen and the colour of each varied at will. this is likely to prove of considerable value to designers of wallpapers and coloured fab- rics, as well as having a possible application for the projection of luminous scenery on the stage. artificial daylight-—efforts have also been made to provide *< artificial daylight,” 7.c., to correct the light from artificial illu- minants and render it equivalent to normal daylight for the match- ing of colours. two methods of effecting this correction have been applied. in the sheringham unit the light from a gas-filled lamp is reflected from an upper surface coated with a pattern of 1the sperry searchlight, electrician (feb. 2 1917); haydn t. harrison, fi/um. eng. (march 1918), 21. bloch, lichtiechnik (1921). 8 jilum, eng. (may 1925). illuminating engineering green, blue and a small amount of yellow in suitable proportions. in the system usually associated with the name of mr. f. e. lamplough, the light is filtered through a combination of tinted glass. in either case the efficiency of the apparatus is necessarily low, 60% or more of the original light being lost in making the correction. but the advantage to firms in the dyeing industry and others concerned with delicate colour-matching of having an invariable artificial light, independent of the wide variations of natural daylight, is very considerable. industrial applications——the problems of the lighting of streets, schools, factories, shops, etc., of the avoidance of eye strain in cinema theatres and the importance assigned to proper lighting in factories, the interests of health, safety and efficiency of work, have been investigated by the illuminating engineering society and home office committees.4 evidence on lighting requirements in factories has been collected from many different sources, and records of over 4,000 tests of illumination in differ- ent factories have been presented. the minimum values of illumination in the interests of safety (o-25—o-4 ft.c.) are es- tablished. recommendations on the subject of avoidance of glare, flickers andl inconvenient shadows have been made, and the illumination required for carrying out work done is shown to be not less than three foot-candles for fine work and five foot-can- dles for very fine work. consultations with various joint industrial councils are now proceeding with a view to determining what constitutes suitable and adequate lighting for processes in their respective industries. progress in the united states —-in the united states detailed codes of industrial lighting have been adopted in seven different states. in principle these follow closely the recommendations of the british committee. methods of grading various lighting units according to the degree of “ glare’”’ are outlined, and the positions which may safely be assigned to such units in a work- shop are tabulated. the codes also contain standards of the illumination requisite for various processes, a distinction being drawn in the most recent codes between the minimum value desirable and higher values recommended in the interests of economic production. a considerable amount of research has been devoted to the relation between conditions of illumination and efficiency of work. thus it has been shown by dr. ives of the united states public health service that the dispatching service in post offices was expedited and rendered more accurate by better conditions of illumination; tests in laboratories in germany have likewise revealed a close connection between illumination and many processes involving exact vision and manual dexterity.6 the subject of industrial lighting has like- wise been studied by the international labour bureau of the league of nations in geneva. particularly difficult cases of industrial lighting also form the subject of study by the committee on illumination, working under the department for scientific and industrial research, on which eminent architects and medical men, besides lighting experts, are represented. this committee also deals with all inquiries bearing on illumination received from the various gov- ernment departments. in connection with this and other aspects of lighting, increased attention is now being devoted to the hy- gienic side, and at the international congress for the study of industrial hygicne held in geneva in 1924 a special resolution was passed accepting good illumination as of equal importance with heating, ventilation and sanitary conditions, in the interests of health and safety. standardisation.—standardisation in various fields is being dealt with by various sub-committees, working under the british engineering standards association, which have prepared speci- fications on the performance and dimensions of electric lamps, and have also recently issued standard specifications for portable 4 reports of departmental (home office) committee on lighting in factories and workshops, firsi report, cmd. 8,000, vol. i and 2 (1915); second report, cmd. 1418 (1921); third report, cmd. 1686 (1922). 5 tilum. feng. (april 1925). 6 tum. eng. (april 1925). illustration illumination photometers! and reflectors used for industrial light- ing.? other subjects now being dealt with include lighting glass- ware, and the illumination of schools, offices and streets. trafic and lighting —experience during recent years has shown that the questions of lighting and transport are closely related. with the progressive increase in the volume of fast- driven motor-traffic the necessity for good public lighting has become even more urgent than in the past; and the increase in the number of street accidents year by year has drawn public attention to the importance of the question. a new problem is presented by the lighting of arterial roads connecting cities. these routes are primarily intended for fast motor traffic and their utility will not be fully realised unless adequate artificial lighting is provided, enabling them to be used with safety by night as well as by day. special methods of illuminating such routes are now the subject of consideration. many devices eliminating glare from powerful automobile headlights have been suggested, some of the most promising based on the limitation of the main portion of the beam below a certain horizontal plane so as to avoid the direction of rays into the eyes of approaching drivers or pedestrians. but the most hopeful solution lies in the provision of better public lighting, which would render very powerful headlights unnecessary. progress in these various directions has been aided very greatly by the introduction of simple forms of instruments for measuring illumination, of which quite a variety of types are now available. the information acquired in this way has been very helpful in framing recommendations for the degree of illumination neces- sary for various purposes. bibliography.—.a. p. trotter, z//umination, tts distribution and measurement (1911); l. gaster and j. s$. dow, afodern lluminants and illuminating engineering (1920); m. luckiesh, artificial light, ats influence on civilisation (1921); lichttechnik, ed. by dr. l. bloch and issued by the german [luminating engineering society (\lu- nich, 1921); j. w. t. walsh, elementary principles of lighting and photometry (1923); see also the illuminating engineer (the journal of good lighting), official organ of the illuminating engi- neering society; the transactions of the illuminating engineering society in the united states; and lichi und lampe (official organot the iiluminating engincering society in germany). (io ga)