TESTING MACHINERY

machinery employed in the determination of the mechanical properties of bodies, or, in the widest sense, the complete relations between load and dis- tortion. since the conditions which prevail during the determi- nation of any such relationship have a great effect upon the results—a large number of accurate physical measurements 2re required for a reasonably complete statement of the mechanical properties of a body. the term “ machinery ” includes the del- icate instruments which are necessary for many of these meas- urements. purpose of tests—the main objects of the tests which are carried out with the aid of testing machinery are: (1) to determine with the greatest possible accuracy the behaviour of materials when loaded; (2) to furnish criteria for the selection and for the manufacture of materials of definite properties, and to insure that such properties are obtained; (3) to furnish criteria for the design of articles constructed from such materials to withstand defined conditions of loading, ard to insure that such articles conform with requirements. in the present state of knowledge many of the criteria are necessarily of a tentative kind. the information required in recording the results of a test in- cludes the nature of the material, the shape, size and temperature of the body, the intensity of the load and the manner in which it is applied. the functions of testing machinery are to apply the required loads to pieces of specified material of specified shape under definite conditions, to measure the intensity and conditions of application of those loads and to measure the resulting distortions of the pieces under test. the material and its [istory—a description of the nature of the material involves as complete a statement as possible of its natural and industrial history, and of its chemical and physical constitution. the importance of this information is now more fully realised than formerly. an accurate test result may be rendered of very small value by the absence of such data, because relatively large differences in mechanical properties may be correlative with apparently small differences in the constitution of the material. the conditions under which a test is to be carried out require some consideration. when a load is applied to a body, the body suffers a change of form which varies with the load and with its manner of application, and depends also upon the original shape of the body and upon its physical condition. it 1s convenient, therefore, in comparing one material with another to deal with pieces of standard shape to which loads are applied in a standard manner; but the relative behaviour of two materials may be different if the form of the standard shape be altered or if the load be applied in some other standard manner. in testing finished articles it is accordingly wise to apply the load in a manner which conforms as closely as possible with the expected conditions of loading when the article is in everyday use. as a rule the change of shape of a body cannot be continued tesla—testing machinery indefinitely, but reaches a limit at which the body breaks. the load which is necessary and sufficient to cause fracture is called the strength of the body under the given conditions, and is of course an important mechanical property. standard shape.—the standard shape most usually employed in tests of materials is that of a cylinder or of a rectangular prism. it is not possible to arrange that all test pieces of standard shape shall be of the same size; the dimensions of pieces of different size are arranged to be as nearly as possible in accordance with the principles of similitude. the standard manner of loading the test piece may be such that at any cross section of the piece the internal forces in the material are equivalent to a single force; this is called direct loading. or the load may be applied in such a way that the internal forces at a cross section of the material are equivalent to a couple, or to a force combined with a couple; this is called momental loading. in direct loading the applied force may be a pull or a push, giving rise to lengthening or to shortening re- spectively of the test piece. in momental loading the applied couple may lie in a plane parallel to that of a cross section of the test piece or in a plane at right angles thereto, giving rise to twisting or to bending respectively. in combined loading the piece is subjected to two or more systems of externally applied load. the rate of loading is of importance because the distortion of a body requires time for its accomplishment. in so-called static tests the load is applied to the test piece slowly and with- out shock. in impact tests the load is applied abruptly as a blow. fatigue tests require the repeated application of a load insuffi- cient, when only once applied, to cause the failure of the test piece. | variety of tesis and machines.—such variety of procedure necessitates a corresponding variety in the machines in which the tests are to be performed. many machines are built which will carry out all the usual static tests, tension, pressure, bending and twisting, as well as others not so frequently employed, such as punching, shearing, drifting and bulging; these are sometimes termed universal machines. they have the disadvantage that a change in the kind of test necessitates more or less extensive alteration in the movable fittings of the machine. when only pieces of a definite standard size are to be accommodated this difficulty may be overcome by suitably designing the machine. if the articles to be tested are of considerable variety in size and shape it is more convenient to have a separate machine for each kind of test; but it is well 10 provide a measure of adaptability for unusual tests and odd sizes of articles. complex stresses.—in tests where complex stresses are in- volved, and the effect upon the experimental results of a change in the dimensions of the test piece, or in other conditions, is not amenable to reasonably accurate calculation, it becomes neccs- sary to define rigidly the design and manner of operation of the testing machine and the dimensions of the test piece. in some degree this arbitrary choice of conditions applies to all tests, and it indicates our limited knowledge of the relations between load and distortion. thus for a metal bar broken by pulling, the degree of stretching of any region of the bar varies with the longitudinal position of that region; for the purpose of a rational comparison the stretch must be made referable to a uniform length in bars of uniform size, or te properly proportionate lengths in bars of different sizes, and the choice of standard lengths is governed chiefly by their general convenience for testing purposes. in other cases the arbitrary nature of the conditions of test is more evident, as for instance in the determi- nation of the “‘ setting time ”’ of cement, in the dimensions of the impact bending machine and its test piece, and in the determina- tion of the “ wear’’ of paving materials. in such cases the results allow of the comparison of the behaviour of pieces of similar form under complex but rigidly controlled conditions. if those conditions are well chosen the test results may be correlated with the behaviour of pieces of similar material in actual use; if correlation cannot be eventually established the test is of little value. tetanus mode of operation.—testing machines for static tests are usually operated either directly by hydraulic power or through intermediate gearing by a heat engine or an electric motor; small machines are operated by hand through gearing. for compara- ble results it is desirable to obtain close regulation either of the rate at which the load is applied or of the rate at which the test piece is deformed, but though such regulation has been accom- plished in many circumstances it is not readily attained in gen- eral testing. the forces are transmitted to the test piece through special bearing pieces and other fittings, which must be care- fully designed to secure the intended distribution of load. the forces are usually measured either by means of a lever system and weights, or by some form of hydraulic gauge. in impact tests the source of energy is nearly always a falling weight, fre- quently arranged as a pendulum, and the energy of the weight is measured before and after the blow. repetitive tests involve either a rotary or a reciprocating motion, and this is generally derived from an electric motor. the load is applied directly by weights or by springs, with dashpots to damp vibrations, or by a magnetic arrangement or indirectly by the inertia of the moving parts of the machine. | the dimensions of the test piece and the changes in its di- mensions, unless they are large enough to allow of direct meas- urement to a sufficient degree of accuracy, are obtained by means of instruments which magnify either mechanically or optically or by a combination of these methods. some description and illustration of testing machines and apparatus is to be found in the article “ strength of materials’’! (see 25.1007). these and similar appliances are in everyday use and yield useful and accurate information. but the whole subject is now on a wider basis than formerly, chiefly as the result of investigation of the constitution and structure of ma- terials. the coarser details of structure have been revealed by visual and by microscopic examination, while the minute details of crystalline, colloidal and atomic structure have been deduced from various kinds of physical measurements. certain funda- mental mechanical properties have been placed upon a physical basis. many problems of stress distribution have received useful mathematical solutions. many other such problems have been solved experimentally, notably by coker using the photo- elastic method! and by griffith and taylor using the soap-film method.? more extensive study of stress-strain relations has been facilitated by the recording device of dalby® and by the cinematograph. many details of the manner and progress of deformation and fracture have been revealed by research.’ (see crystallograpiiy; metallograp:iy.) recent explorative work, carried out by means of apparatus _more fitly described as machinery than the delicate instruments required for the researches mentioned above, has been chiefly concerned with combined systems of static loading, repetitive loading, impact loading and various methods of measuring hardness. experiments on combined static loading received their chief impetus from the results obtained by guest, and are directed to the determination of the relations which exist between the principal stresses and the principal strains in com- plex stress systems. in tests by repetitive loading the early work of wohler has been extended to the improved materials now available. many new types of machines have been devised, and some of these apply complex systems of loading. ingenious methods of measuring distortion allow of rapid estimation of the limits of endurance, and attempts have been made to correlate the quantitative results of tests with microscopic observations of structural change in the material.6 impact tests have been stand- ardised, but more work is required to place such tests upon a satisfactory scientific basis. progress has been made in establish- ing relations between hardness and other properties of a material, and new methods of obtaining more accurate measurements of hardness have been devised.’ the results of these and similar researches have led to the manufacture of improved and even new materials, to incredsed precision and stringency in specifications, to improvements in 1 figures throughout the text refer to notes in the bibliography. 761 testing machines and apparatus and to greater care and accuracy in testing. but we are still far from the day when a few simple measurements may allow the mechanical behaviour of a ma- terial under any conditions of loading to be deduced. for tests of bridges and other large structures, the apparatus must be brought to the structure, which is then loaded by dead weight or by moving vehicles in appreciably heavier degree than it is expected normally to undergo. measurements, interpreted with knowledge of the principles of design, of the distortion at regions of severest stress, combined with an examination of those regions of the structure while under load, afford a reliable indication of the resistance of the structure. special instru- ments have been devised for convenience in measuring distor- tions of large structures. bibliography.—(1) british association reports on stress dis- tribution in engineering materials (1914, 1915, 1916, 1919, 1921, 1923); (2) g. i. grifhth and a. a. taylor, proc. inst. mech. eng., di 755.48017): (2) we. dalby; strength and structure of steel and other metals (192 3); (4) w. rosenhain, an intreduction to the study of physical metallurgy (1914); (5) j. j. guest, phil. mag., vol. 50, p. 69 (july 1900); (6) if. j. cou the fatigue of metals (1924); (7) proc. inst. mech. feng. many papers between 1916 and 19253 j. c. smallwood, mechanical laboratory methods (1918); r. g.c, batson, mechanical testing, 2 vol. (1923); testing, monthly, n.y, g.) tetanus or lockjaw (see 26.669).—on the appearance of tetanus in the british army during the early days of the retreat from mons immediate steps were taken to cope with it. the disease could be prevented if a dose of anti-tetanus serum were given as soon as a wound was sustained because some days elapse before the bacilli, which remain in the wound, are able to secrete sufficient poison to precipitate an attack. from that time every wound, no matter how slight, was followed as soon as possible by a dose of anti-tetanic serum. out of 1,242,000 wounded men who were sent home to england, 1,458 cases of tetanus arose, giving a ratio of rather more than 1 per 1,000. in sept. 1914 the ratio of tetanus cases to wounds was 9 per 1,000, in oct. 1918 the ratio was o-5 per 1,000. in nov. 1914 preventive inoculation, introduced about the middle of oct. 1914, had begun to exercise its beneficial effects. the following figures giving the number of cases of tetanus per 1,000 wounded men make this clear: — cases of cases of tetanus tetanus sept. 1914 . 9:0 feb, ; i- oct. 1914 . 73 mirch’ ae : o- nov. 1914 . 2°3 april 1915 a dec. 1914 . 2 1:4 may i915 jan. 1915... ere) june 1915 the same experience was met with in the french and german armies. as soon as preventive inoculation with anti-tetanic scrum became a universal practice the incidence of tetanus dropped sharply and remained small. in june 1917 it was ordered that each wounded man should receive not one in- oculation as formerly but four, at intervals of a week, because the minimising effect of the serum passes away rather quickly. the effect is not always to prevent absolutely. but even in those cases in which tetanus does supervene in spite of the in- oculations, the incubation period is lengthened and the death rate is lowered; other things being equal, a long incubation period tends to result in a milder attack than a short incubation period, thus any circumstance prolonging the incubation period will also tend to lower the death rate. only 26-9% of the in- oculated are attacked during the first fortnight, ei ctean 68-90% of the uninoculated are attacked. among the protected 40:0% have an incubation period of more than 35 days; among the unprotected only 6:5%. the average incubation among inoculated is 45-5 days, among uninoculated 10-9 days. indeed, in each year of the war the incubation period tended to rise. further, the inoculations tended to limit the degree of tetanus, converting what would be generalised cases into local or one- limb cases. the following table illustrates this:— 762 percentages tetanus type iqi5 1916 general local local tetanus tends to occur in the wounded or injured limb and to be confined to that limb. it is much less severe and far less fatal than the generalised type. naturally the death rate reflected these successes. among the unprotected and un- recorded the death rate per cent was 53-5. among the protected it was 23-0. the “ unrecorded ”’ here undoubtedly include cases which had received a dose. the method employed during the warfully justified the hopes which were entertained concerning it. binliography.—maj.-gen. sir david bruce, k.c.b., f.r.s., the prevention of tetanus during the great war by the use of anti- tetanic serum, research defence society, form d2 (july 1920). tewfik, ahmed pasha (1845- ), turkish statesman, was born in constantinople feb. 11 1845, the son of ismail hakki pasha. in 1866 he went to the ministry of foreign affairs, where he spent six years. after acting as first secretary to the turkish legation in athens, he was sent to st. petersburg (leningrad), where in 1877 he received prince gorchakov’s note declaring war. the following year he became turkish minister in athens, in 1885 he went to berlin as ambassador, and remained there for ro years. in 1895 he was appointed minister of foreign affairs, which post he filled during 14 years; and on the termination of the greco-turkish war it was he who signed the peace treaty with greece in 1898. after the young turk revolution he became grand vizier, and in 1909 he was sent to london as ambassador, where he remained till 1914. in 1919 he was reappointed grand vizier, afterwards becoming president of the senate, and in 1921 he attended the london conference ar- ranged by the supreme council of the allics. the following year he retired into private life. during his long career of more than 60 years, tewfik pasha played an important part in turkish affairs. his conciliatory spirit won him universal admiration and the agreements which he concluded with the balkan states did much to improve relations between these states and turkey. texas (see 26.688), a state of the united states of america. in 1923 the population was 4,939,630, as against 4,663,228 in 1920 and 3,896,542 in 1910, an increase since 1920 of 276,402, or 5-9 %, as against 19-7 % in the decade from 1910-20. the urban population (in places of 2,500 or more) was estimated at 1,605,- 380 in 1923 or 32°5% of the total, as compared with 32-4% in 1920. the average number of inhabitants per sq. m. increased from 14:8 in 1910 to 17-8 in 1920 and to 18-8 in 1923. the esti- mated population for 1925 was 5,097,574. the following table shows the growth of the cities having, in 1920, a population of more than 100,000:— city 161,379 158,976 138,276 106,482 san antonio dallas . houston fort worth agriculture —the 1910 census gave texas 417,770 farms with a total area of 112,435,067 ac., of which 27,360,666 ac. were im- proved. the 1920 census showed 436,033 farms, with a total area of 144,020,521 ac., of which 31,227,503 ac. were improved. this was an increase in improved farm land of 3,866, 837 ac. be- tween 1910 and 1920. the value of all farm property in 1920 was $4,447,420,321. the principal crops of 1924, in the order of acre- age, were cotton, corn, oits, grain sorghum, wheat, hay, rice, barley, peanuts, sweet potatoes, sorghum syrup, watermelons, broom corn, rye and onions. these crops covered 27,981,000 ac. ; their farm value, partly estimated, was $789,117,000. in 1g19, at the peak of post-war prices, their value was $1,051,817,000. texas is a large producer of fruits and vegetables. the average annual yield of torn, 1911-9, was 126,600,000 bu.; 1919-24, tewfik—texas 130,805,666 bu.; of wheat, rorm—9, 15,300,000 bu.; 1919-24, 20,552,000 bu.; of cotton, r9g11—24, 3,651,000 bales. livestock.—the following table shows the numbers and values of livestock in rg21 and 1924 (figures of u.s. dept. of agricul- ture) (o00’s omitted) :— 1924 a val ue number nt oo ame, fae! (nt range cattle 4,500 | 213,184] 5,597 | 139,183 milch cows | 1,840 - 1,063 - horses 1,187 89,000 980 53,900 mules 800 | 84,744 854 | 73.344 sheep . 3,0007 | 19,335'| 3,097 | 18,272 swine . 2,42 28,6 2,165 17,136 11920. minerals —the most important mineral products are oil, sul- phur, coal and lignite. at the beginning of 1925 there were go producing oil fields, covering all sections of the state. —the hum- ble field in harris county was opened in 1905, goose creek in 1gt1, and blue ridge and the west columbia field in brazoria county in r919. the burkburnett field in wichita county first became impostant in 1917, ranger in eastland county in 1917, and desdemona and breckenridge in comanche, and stephens counties respectively in 1918. in 1922 an important ficld was discovered in reagan county on land belonging to the university of texas. production dropped from 28,000,000 bbl. in 1904 to less than 9,000,600 in 1910; rose to 27,644,000 in 1916; 32,413,000 in 1917; 38,750,000 in 1918; 85,312,000 in 1919; and 128,847,156 in 1924 (see petroleum). the value of natural gas marketed in the state rose from $127,000 in 1909 to $10,623,000 in 1922; natu- ral gasolene in 1923 amounted to 177,765,000 gallons. two sulphur plants in texas and one in louisiana were said, in 1920, to yield 98°% of all the sulphur produced in the united states. one of the texas plants is at freeport, near the mouth of the brazos river; the other is near matagorda, close to the mouth of the colorado. the freeport plant began producing in sub- stantial quantities in 1916, and the next year, under war pressure, delivered 500,000 tons a year. the yield of bituminous coal in 1923 was 175,332 tons. lignite is mined chiefly for home consump- tion; the 1923 yield was 1,011,997 tons. other minerals of fairly steady yield are silver, worth about $500,c00 per annum, quicksilver, cement and clay products. quicksilver is produced at the terlingua mine in brewster county; the highest yield re- corded, 10,791°75 lb. flasks in 1917, was valued at $1,136,502. cement production in 1924 was 4,400,000 bbl., valued at $9,500,000. clay products (brick, tile and pottery) in 1923 were valued at $4,800,000. salt is produced in fairly steady quantities, and in 1920 yielded 91,103 short tons, with a value of $667,835. manufactures —in 1920 there were 5,724 manufacturing estab- lishments, capitalised at $535,776,451, employing 107,522 per- sons, and producing an annual value of $999,995,796, of which $ 208,824,898 was value added by manufacture. the principal industries were those concerned with lumber; cotton and cotton- seed products; printing and publishing; oil refining and allied products; flour and grist-milling and food preparations. the lum- ber production was 1,500,000 ft. for 1924, when texas ranked sixth in this industry, as it had done in 1910 and 1915. commerce.—the chief ports are sabine, port arthur, orange and beaumont in the sabine district, importing chiefly crude oil and exporting refined oil and oil products; and houston, texas city, freeport and galveston in the galveston district, which ex- port cotton, grain and sulphur. the port of houston was opened in 1915, its access to the gulf of mexico being through the houston ship channel, formed by the widening and deepening of bulfalo bayou. the distance from the municipal docks to the gulf is 54 miles. unofficial figures for 1924 fixed the value of im- ports through galveston, including the subsidiary ports of the district, at $37,354,862, and the exports at $547,632,800, making galveston second to new york as an exporting port in the united states, a position which it had held for some years. these fizures did not include coastwise traffic. in 1923 the tonnage tex tile machinery passing through the ports of the galveston district was 12,451,811. in 1920, 1,233 vessels cleared for foreign ports, of which 849 were american, 222 british, 29 norwegian, 26 italian and 18 mexican. the bulk of their cargoes was made up of 2,126,717 bales of cot- ton and 44,726,000 bu. of wheat. finance.—the value of all property assessed for state taxation on aug. 31 1924 was $3,419,091,814. the ratio of assessed value to real value varied from 662° % in some cities to 25% in some rural districts. the total receipts of the state treasury for the year were $34,849,557.81, and total expenditures $34,849,557-81. on june 30 1924 there were 846 state banks in operation, 176 of which were members of the federal reserve system in 1921. on oct. 10 1924 there were 576 national banks in operation. education.—for 1925 the school population (seven to 18 years of age) was 1,335,000; and the number of teachers employed in public schools (1924) was 35,4590, of whom 4,347 were negro. the practice of making legislative appropriations to supplement the available school funds began in 1915. a compulsory atten- dance law became effective in ror8. a law of april 3 1918 re- quires all public school work to be conducted in the english lan- guage. administration.—the industrial accidents board was created in 1913, primarily to administer the employers’ liability act. the board of water engineers was created in 1913 to regulate the use of public water for irrigation and all other purposes. the highway commission, established in 1917, is charged with the administration of all highway laws, including that of the registra- tion of motor vehicles. on nov. 1, 1924, there had been com- pleted under its supervision 17,000 m. of approved highways, costing $28,687,095; at the same time contracts were in progress for the construction of 1,812-57 miles. the commission reported the registration during 1924 of 801,080 automobiles and trucks and 2,324 other motor vehicles. the state board of control was created in 1920, in an effort to consolidate administration and to co-ordinate the state budget. the railroad commission reported in dec. 1923 15,860°71 m. of railroad in operation, a de- crease of 234°14 m. since 1922. ilistory.—a constitutional amendment providing for state- wide prohibition was voted down in 1911. prohibition by local option made great progress, however, and by 1918 more than three-fourths of the area of the state—including the cities of dal- las, waco and austin—was dry. the legislature in march 1918 ratified the federal amendment and in april put into effect the ““ zone ”’ law prohibiting the sale of liquors within 10 m. of a mili- tary, naval or ship-building establishment. in june 1918 statu- tory state-wide prohibition was established, and doubts of the constitutionality of the act were ended by the carrying of the amendment for state-wide prohibition in 1919. a law of march 26 1918 permitted women to vote in party primaries and nomi- nating conventions; but a constitutional amendment, submitted the next year, to enfranchise women in regular elections failed, the legislature, nevertheless, ratified the federal woman suffrage amendment in july 1919. the effect of the world war is seen in a law of april 2 1918, confining the franchise in primary elec- tions to citizens of the united states; and in another of march 23 1918, amended a year later, providing that assistance should! be given at the polls in the english language only and to persons physically unable to write or to those past 60 years of age and unable to write. the governors of texas after rg10 were: oscar branch colquitt (dem.), 1911—5; james e. ferguson (dem.), 1915-7 (impeached) ; william p. hobby (dem.), 1917-21; pat m. neff (dem.), 1921-4; mrs. miriam a. ferguson (dem.), 1924- . (ec. ba:) textile machinery.—a so-called artificial wool has been placed on the market; but it still is far from the natural wool fibre. should a reasonably satisfactory artificial wool fibre be ultimately produced it will be necessary to devise particular processes and machines for its manipulation along the lines at present in use for english wool “ drawing ”’ and “ spinning.”’ artificial wool.—lf the present artificial wool is prepared and spun into yarn on the french system—a system which should give the fullest possible thread and resultant cloth—it is still too 763 solid for the french type of fabric, partaking more of the char- acter of a peruvian cotton yarn than of a botany yarn. there- fore, the processes of manufacture and the machines for carrying out these processes will have to ensure greater fullness or, on the other hand, a characteristic hardness and lustre; the develop- ment of necessary processes and machines for attaining one or other of these ends in the near future may become a dominant feature in the industry. as the differences observable in dyeing artificial wool as against natural wool give rise to changes in machine design, the coming of artificial wool—if and when it does appear—will lead to the evolution of processes of manipulation and machines to carry them out. structural improvements.—referring to structural improve- ments in textile machinery, attention should be directed to the increased employment of ‘‘ chain drives ” and “ roller and ball bearings.” the tendency toward more positive control has naturally favoured the use of chains in cards, looms, etc. the increase in roller and spindle speeds in carding, combing, draw- ing and spinning have called for experimental work with roller or ball bearings in order to reduce wear of parts, better or simpli- fied oiling and accuracy in setting. opinion ts still clivided as to the merits of roller or ball and plain bearings respectively. noble comb circles certainly seem to be improved in running if run on ball-rolls but many carding engineers still prefer the plain bearing. in those sections of the industry where little improvement in manipulating skill has been called for, little or no advance has been made, whereas in those sections where there has been a constant pressure conducing toward efficiency, there has been a steady advance in the perfecting of details, which in the aggre- gate total up to a considerable move forward. thus in the wool industry, owing to ladies’ fashions favouring a small area of body covering of a medium to heavy weight, pressure has been taken off efficiency in fine yarn spinning, and about one-quarter of the spinners and weavers are required for a given production as compared with, say the “ crinoline ”’ period of 1860. the pres- sure toward efficient output has also been removed. should fashions change toward lighter fabrics requiring finer yarns, the industry will need speeding-up machines and processes. the preparatory processes —the thorough cleansing of wool preparatory to combing and spinning is still under serious dis- cussion. broadly speaking, most firms have usefully stabilised both their scouring hquors and their method of mechanical control. a firmin the roubaix district, however, being convinced that to scour wool in its own wash-water products is the most natural and best process, has designed the necessary mechanical control to effect this. the patentees claimed that a softer, opener wool is delivered under this process as compared with similar wool treated on the normal lines, z.c., without preliminary steeping. petrie’s “self-cleaning bowl” for wool-washing is proving useful in many cases where with the normal bowl a very variable result would be obtained. mention should be made of the self- cleaning card, the sclf-cleaner usually being either a special roller or a development of the fancy. in some cases these self-cleaners have undoubtedly been a success, but it is still questionable whether they constitute an improvement upon a fancy clothed with wire bent at the correct angle and properly speeded and set in relation to the swift. an important result of the better me- chanical construction of the card is the marked increase in production, this in some cases amounting to an increase of at least 50%. the carbonising process for freeing wool from vegetable matter usually subjects the material for a long time to a weak acid solu- tion and then concentrates the liquor by drying. the more re- cent idea is to subject the wool for a very short time to a much stronger acid solution, a process which seems better suited to “ cloth-carbonising ’’ than to “ wool-carbonising ” as the ma- terial so treated is slightly yellowed. perfect mechanical control is here necessary, the “ time factor ” being all important. the best cotton opening and scutching machinery gives “ the best cleaning power without damage to the fibres and the most regular lap-sheet with a minimum of labour.” this ideal is 764 being attained by the better mechanical construction of opening, scutching and carding machinery. the mechanical advances made in connection with flax—a fibre often difficult to treat mechanically—may be mentioned. the flax-pulling machine is an accomplished fact and the automatic hackling machine is in use. valuable work has been done by the research assns. in the fields of physics and chemistry on the preparatory and other proc- esses for wool, cotton, flax, silk, etc. usually the revisions of processes advocated may be effected with the standard machines so that little mechanical revision has been called for. combing.—with reference to wool-combing, the french comb is being adopted by the wool industry very slowly, although almost universally used on the continent and in australia, due perhaps to present day “‘ fashions ’? which do not call for the finer yarns. in the cotton trade, however, the heilmann comb not only dominates but is step by step being improved in design. thus, in nasmith’s improved heilmann comb “ reduction in wear and tear of the detaching roller surface ’”’ ensures much better combing results. it seems impossible to hope to treat flax-combing or dressing on any sort of really continuous line, but spun silk, which so far has been almost wholly prepared for drawing and spinning on the flax dressing-frame, is now being treated on the continuous system, although it is too early to say whether the results will be equal to those produced by the old method. drawing and spinning.—in the wool industry machines of the intersecting gill-box type are being increasingly introduced. the details of the gilling and drawing boxes for wools are being more and more carefully worked out, even the electrical po- tentialities of the surfaces against which the slivers rub being carefully considered. special reference should be made to the almost daily increase in the self-dippers in use m the worsted spinning industry. in the cotton drawing-frame various devices have been tried to obtain better control of the comparatively short fibres between the drawing rollers, with some success, but the wear and tear of the various parts or additions are a scrious consideration. in ring-spinning in the cotton industry the spindle-drive is in a state of transition and the adjustment of part to part has not yet been so satisfactorily solved that the machines may be said to be stabilised. on the other hand the mule may almost be said to have been evolved to a stable form. in wool spinning, perhaps the most notable change has been the tendency to adapt the ring-frame to fine wool spinning. as to developments in the singeing of cotton yarns the gas flame has been more scientifically studied with the idea of pro- ducing the type of flame most suited to the purpose in view. the control of the thread and the intensity of treatment along with the getting away from the operatives of all the obnoxious prod- ucts of combustion have also received most careful and suc- cessful consideration. artifictal sik.—the development of the artificial silk industry has drawn the attention of manufacturers to the winding or spool- ing process. so long as variations in tensioning did not markedly show in the cloth this process received scant attention, but now in most of the industries this matter is regarded as important and in the silk and “‘ rayon ” industry of dominant importance. the tensioning and winding of the yarn on to the spool or bobbin are now so successfully carried out that practically perfect pieces are produced, whereas previously very marked imperfections were observable. weaving.—the most noticeable attempt to improve the loom is the endeavour which has been made to throw the shuttle without either “over” or “ under” picking arms. this has been successfully accomplished; the only question is—at what cost? the necessary strap and wheel connections in the new mechanism certainly bring the economies of the solution strongly to the front! minor changes are producing an extraordinary dif- ference in the fabric. the northrop loom now meets the require- ments of trades other than the plain cotton trade. efforts to simplify looms and mechanisms for producing figured fabrics thames are still being made, but so far without any outstanding success, although the carver loom maintains its position in the linen industry. fimtshing.—the “scientific control” is steadily making headway. the “ hydrogen-ion concentration ” seems to be the password in all fields of science at the present moment and al- though certain agents are known to promote the milling or felting of wool cloths, it has only recently been appreciated that a particular concentration of the bath is the dominant factor— jess concentration and less milling but equally greater con- centration and less milling! then again the interesting series of british wools provided for the university of leeds by the royal agricultural society revealed in their milling properties variations of structure in the distinctive british wools which are leading to most remarkable deductions with reference to the fundamental structure of the wool fibre. this research bids fair to revolutionise some of the finishing processes which are daily becoming more scientific. kuitting and kuttting machinery.—vascinating improve- ments in the possibilities of design and colour have been made, and flat-warp machines developed in which a texture is produced which bids fair to make a position for itself in men’s wear markets. brpl1ography.—r. beaumont, weollen and worsted (1919); a. brown, construction of the power looms (1921); a. f. barker, wool and the textile industries (1919). (a. f. b.) thames, england (see 26.723).—a comprehensive scheme for the disposal of flood water was prepared in 1914, but proved too expensive. in 1921, however, a programme, involving an ex- penditure by the conservators of £290,000 over a period of seven years, was approved by parliament. in the first two years £130,- 000 was spent on the improvement of weirs, locks, etc. ‘the peri- odical thames floods are not as formidable as they were, owing to the work of the thames conservancy in dredging and enlarg- ing weirs, but difficulties have arisen owing to the interference with natural drainage caused by the development of land in the thames valley, the building of narrow bridges over tributary streams, the filling up of ditches, etc. the floods, such as those of 1925, are also rendered far more noticeable by the number of small houses erected on land subject to inundation. a large sum has been spent on dredging and new locks between lechlade and oxford, but there has been little increase in the traffic. a large double lock and transporters were opened at boulters’ lock, mai- denhead, in 1912, and later the course was widened at henley. a new lock has been built at mapledurham. locks, weirs and other improvements have been made at iffley, and a lock (the largest on the river) and a boat conveyer at teddington. the thames bridges-—much attention has also been given to the problem of the london bridges, and a committee of the lon- don county council was formed to inquire into the subject in 1924. the proposal to build a bridge at st. paul’s, authorised by parliament, met with much opposition from the authorities of the cathedral. proposals for the reconstruction of lambeth bridge (closed to vehicles in 1910 in the interests of public safety), and for widening the albert embankment and lambeth road were in an advanced stage in 1924. owing to subsidence, water- loo bridge was closed in 1925 and a temporary bridge was erected alongside. the london county council decided, despite opposi- tion, to remove the old bridge and to build a new one of five spans and carrying six lines of traffic; a proposal to invite designs in competition was announced in march 1926. the bridge near datchet has been demolished, and a new concrete bridge was in course of erection in 1925. a new bridge at reading was opened in 1923, and the old one was being rebuilt in 1926. the question of a tunnel under the thames to give further facilities for traffic between the east of england and the southeastern counties has also received attention. estimates for its construction be- tween tilbury and gravesend were prepared in 1924, and an engi- neering survey was undertaken in 1925. precedence was given, however, to other road improvements nearer the centre of lon- don. a scheme promoted by sir samuel instone in 1924 for a fleet of motor boats on the river between hammersmith and thayer, a. h—theatre greenwich and woolwich did not materialise, as the london county council was not prepared to provide the necessary piers. in 1924 &@ company initiated a scheme for the construction of a wharf, a mile long, at west thurrock, about 18 m. from london bridge, to accommodate the largest vessels, with industrial de- velopment on modern lines of an area of 3,000 acres. (oj orcie) thayer, abbott handerson (1849-1021), american painter and naturalist (sce 26.728), died at dublin, n.it., may 29 1921. during the world war he worked in england on the development of camouflage. thayer, william roscoe (1859-1923), american writer, was born in boston, mass., jan. 16 1859. he studied at st. mark’s academy, concord, n. h., travelled with a private tutor in europe, and graduated from harvard in 1881. he was assistant editor of the philadelphia evening bulletin, 1882-5 and then returned to harvard, receiving the degree of a.m. in 1886. he was editor of the harvard graduates’ magazine 1892-1915. in 1903, at the international historical congress at rome, he represented both harvard university and the american historical assn., as also in 1906 at the italian histori- cal congress in milan. he was a member of the harvard board of overseers from 1913 to rorg. in 1918 he was clected president of the american historical association. he died at cambridge, mass., sept. 7 1923. thayer was best known for his works on italian history, especially the dawn of italian independence, 1814 to 1840, 2 vol. (1893); a short history of venice (1905), and the l:fe and times of cavour, 2 vol. (1911). his other works include jialica (1908); the life and letters of john hay, 2 vol. (1915); letters of john holmes (1917); theodore rooseveltt—an intimate biography (1918); democracy: discipline: peace (1919, lectures at brown university); volleys from a non-combatant (1919); the art of biography (1920, lectures at the university of virginia); and george washington (1922).