ND REESE LIBRARY OF THK UNIVERSITY OF CALIFORNIA Deceived > 1 9 ' o. 85288 . Clots No. THE TECHNICAL TESTING OF YARNS AND TEXTILE FABRICS. ABERDEEN UNIVERSITY THE TECHNICAL TESTING OF YARNS AND TEXTILE FABRICS WITH REFERENCE TO OFFICIAL SPECIFICATIONS BY DR. J^HERZFELD r PRINCIPAL OF THE CHEM.-TECHN. EXPERIMENTAL AND TEACHING INSTITUTE, COLOGNE ; FORMERLY INSTRUCTOR AT THE ROYAL HIGH SCHOOL FOR WEAVING, MULHEIM, ETC. WITH SIXTY-NINE ILLUSTRATIONS TRANSLATED BY CHAS. SALTEK SCOTT, GEEENWOOD & CO. PUBLISHERS OF THE |!>affer + 6 (Ba^efte^ dtf ofourman + 6 Sfournaf* etc. 19, 21 AND 23 LUDGATE HILL, CITY, E.G. 1898 PREFACE. CONSIDERABLE attention has always been devoted to the technical testing of yarns and textile fabrics, as the numerous processes employed in practice testify. It was always incumbent on the spinner to control the progress of the spinning process by occasional tests ; and the weaver on his part subjected to ex- amination though very often by the hand and eye alone the material to be worked up. In the last decade new combinations have been effected in yarns, new textile fibres come to the front, and certain deceptions designedly practised, all of which cir- cumstances have so increased the importance, to the spinner and weaver, of submitting the articles to examination, that a knowledge of the methods has become more than ever indispensable. The requirements exacted, now-a-days, with regard to the various qualities of the -goods render it essential for the manufacturer to minutely test both the raw materials, the intermediate products and the finished article ; since not only the public but also (and prin- cipally) the large purchasers of textile fabrics, and the various administrative bodies, such as Army Clothing Departments, Railway Companies, etc., etc., have adopted definite specifications to ensure having VI PBEFACE. good material and workmanship, compliance with which is a necessary condition for the acceptance of the articles supplied. The Customs officials have their processes on which they base their decision as to the duties payable, and the wholesale merchant and retail dealer insist on various conditions when purchasing, in order to comply with the increasing exactions of the consumer. In the present work are collected all the tests, both of a physical and chemical nature, that can, for technical purposes, be performed on yarn or cloth, so that not only the commercial and textile chemist who has frequently to reply to questions of this kind, but also (and principally) the practical manufacturer of textiles and his subordinates, officials, overlookers, the spinner, the weaver, the dyer and the finisher are catered for. Moreover, all those who have to do with the buying and selling of textile goods will be enabled to learn and apply to considerable advantage the various processes described. The appendix, containing the latest official testing specifications for Army clothing and supplies, will be useful to those manufacturers and merchants who give their attention to this class of business. TRANSLATOR'S PREFACE. IN the present work the author has gathered to- gether, probably for the first time, a full collection of the various tests that may, at one time or another, have to be imposed on yarns or cloths, and has illus- trated those in which mechanical force is employed by typical machines. Moreover, he has given us a comparative scheme for the conversion of English yarn numbers into their corresponding values, as well as information regarding the various continental methods of reeling, both of which should prove useful to the English manufacturer doing an export trade, and help to smooth some of the complications arising in the conversion of our own complex system of weights and measures into the metric system, a task of peculiar difficulty as the writer is, from personal experience, aware in the textile business. These considerations will, it is hoped, render the work serviceable to a large circle of readers in this very important branch of industry, as well as to the textile chemist, whose business it is to detect the presence of extraneous fibres in yarn and cloth, esti- mate the loading of silk, and determine the colouring matters that may have been used in dyeing the samples submitted to him for examination. TABLE OF CONTENTS. PAGE Preface . . . . . . . ; . . ' . . v YARN TESTING . . . . 1 I. Microscopic Examination of Textile Fibres ... 3 The microscope : its parts, manipulation and testing . 3 1. Vegetable fibres . 14 (a) Cotton 16 (6) Flax, Linen ........ ^ 18 (e) Hemp ... . . . . * . 1 20 (d) Nettle fibre, China grass (Ramie) . . . . 22 (e) Jute 23 Manila hemp, New Zealand flax, cocoanut fibre, Cosmos fibre . ... . . . 25-26 2. Wool ....... . . . . 27 (a) Sheep's wool 29 (6) Mohair wool ........ 30 (c) Alpaca wool . , . . . .... . 31 Cashmere, Vicuna, llama, camel hair, hare and rabbit fur, horse hair, cows and calves' hair . . 31-33 3. Artificial wools (shoddy, mungo, extract) ... 33 Microscopical examination . . - - 34 Chemical examination 38 4. Silk . . . . . ... ... 39 Silk from Bombyx mori 41 Chappe silk . 41 Tussahsilk . 41 Loaded silk . 42 Artificial silk 43 II. Chemical Examination of Textile Fibres ... 43 Preparation of test solutions 44 1. Characteristic coloration by dye stuffs .... 48 '2. Influence of various salts in solution .... 48 3. alkaline liquids, etc 49 X TABLE OF CONTENTS. PAGE 4. Influence of acids, metalloids, etc. . . . 50 Analytical table for examining mixed fibres ... 51 Qualitative and quantitative estimations . . . 52 Quantitative estimation of the loading of silk ... 55 III. Determining the Yarn Number . . . . . 57 Variations from standard .58 1. Cotton 58 2. Linen yarns - '. 62 3. Jute yarns . . . . . . . ... 64 4. Ramie, nettle fibre . 65 5. Wool . . . . . . . .... . 66 6. Silk ; . . 69 7. Chappe silk 71 Apparatus for ascertaining the yarn number . . . 72 Sampling reels . . 77 IV. Testing the Length of Yarns . . . . ^ . 79 V. Examination of the External Appearance of Yarn . . 81 Yarn tester v . ' . 81 VI. Determining the Twist of Yarn and Twist . 83 (a) Cotton yarns . . 84 (6) Linen yarns . . 86 (c) Woollen yarns ... 86 (d) Silk 88 Apparatus for determining the twist of yarn . . '. 90 VII. Determination of Tensile Strength and Elasticity . . 93 Apparatus for testing the breaking strain of yarn . . 97 VIII. Estimating the Percentage of Fat in Yarn . . . 107 IX. Determination of Moisture (conditioning) . . . 108 Conditioning silk. . . ... . . ^ 110 loose wool Ill worsted . 113 Apparatus 113 TESTING MANUFACTURED FABRICS . . . . . 118 1. Plain or smooth weavings . . . ... . 118 2. Twilled fabrics . . . V . -..' . . . 119 3. Figured fabrics . . ... . .- . . 119 4. Velvety fabrics . , ... . . . . 120 Classification of woven goods . '. . . . . 120 The testing of fabrics . . . . , . . . . 123 TABLE OF CONTENTS. XI PAGE I. Determination of the Mode of Weaving, Distinction and Combination of Warp and Weft Threads . . . 124 II. Testing the Strength and Elasticity of a Fabric . . 125 Breaking strain testers . .... . . 128 (a) Rehse's tester . . > . y- -" . .' . 128 (6) Leuner's . ....... . *. . 128 (c) Breaking strain and elasticity tester . . ,. * 130 (d) Tarnagrocki's tester . . . . . . .132 III. Ascertaining the Count of Warp and Weft Threads in a Fabric . . . ...... . 141 IV. Determination of Shrinkage ... ... . 143 Determining the thickness of cloth . . . . ... . 143 V. Examining the Constituents of the Warp and Weft Weighing . . ... , ". . .. . 144 Weighing on the balance . f . . . '.-.- 144 Determining the weight of cloth from the count and the yarn number . , . . . . . . 144 Determining the weight of the individual constituents of the cloth. Quantitative chemical analysis of the fabric . . . . . . . . . . 145 1. Mixed fabrics containing wool and cotton . . .. 145 2. of cotton and silk . .. . ... . 146 3. of wool and silk . . . ... 147 4. of cotton, wool and silk . . . . 147 VI. Determination of the Dressing , . . .. . 148 1. Physical examination . 150 2. Chemical ... . . . .150 VII. Estimation of the Waterproof Properties of Cloth . . 154 VIII. Determining Hygroscopicity . . . . . . 157 IX. Testing the Fastness of the Dye . . . . . 158 (a) Washing fastness . .. . . . . 159 (6) Fastness under friction . . ... . . 160 (c) Resistance to perspiration .... . . . 160 (d) Fastness against rain . ' . . .... 161 (e) Resistance to street mud and dust . . . . 161 (/) Fastness to weather, light and air .... 162 (g} Resistance to ironing and steaming . . . 163 X. Measuring the Length of Piece Goods . . .164 XI. Determination of Mordants and Dyes .... 165 Xll TABLE OF CONTENTS. PAGE 1. Blue and violet dyes . . . . . . . 169 Testing for pure indigo dyes . . . . . 169 2. Green dyes . . . ; . ...... 170 3. Red and red-brown dyes . . .. . . . 171 4. Yellow and orange dyes . . .... 172 5. Browns, greys and mode shades . . . . 172 6. Black dyes . ... . . . . . 178 XII. Detection and Estimation of Arsenic . . . . 178- APPENDIX. Official specifications for the supply of materials for use in the German Army . 181 1. Cloth . .181 2. Linens and cottons for military use. . . . . 187 (a) Linens . 187 (6) Cottons . '. . . . . . . .188 3. Waterproof materials for military purposes . . 192 (a) Canvas for laced shoes 192 (6) Stuffs for provision bags and knapsacks . . . 196 (c) Tent canvas (for portable tents) ... . 199 4. Linens and cottons for barrack and hospital use and for the training colleges 200 A. Linens , . . . 201 B. Cottons . 202 c. Woollens (flannel) . . . . . '. 202 Contract specifications for French Army clothing . . . 203 INDEX 205 TABLE OF ILLUSTKATTONS. PAGE Fig. 1. Microscope for laboratory purposes . . - . . . 4 ,, 2. with micrometer screw fine adjustment . 4 ,, 3. Revolving carrier for two objectives . ... 6 ,, 4. Hyparchia janira. Scale of butterfly wing ... 8 ,, 5. Pleurosigma angulatum. Test object . . , . 9 ,, 6. Camera lucida . . . ... . .10 ,, 7. Abbe's drawing apparatus . . . . . . . 11 8. Ocular micrometer . . . . . . . . 11 9. Polariser . . ... ...'.. . 12 10. Magnified cotton fibres ... ..." . 17 ,, 11. Sectional view of cotton fibres . . . . . . 17 12. Section of " dead " or immature cotton ... . 17 13. Magnified flax fibres . . ..' . . . .19 ,, 14. Cross section of flax fibres . .- . .' . . .19 15. Magnified fibres of hemp . . ... . .21 ,, 16. Cross section of hemp fibres . ..... . 21 17. Magnified nettle fibres . . ..... . 22 ,, 18. Cross section of nettle fibres . . ... . . 23 ,, 19. Magnified jute fibres . . . . ... . 24 20. Cross section of jute fibres . . . . . .24 ,, 21. Magnified fibres of w r ool .' 29 22. Cross section of wool fibres . 30 23. Camel wool . 1 . .. . . . . . . 32 24. Shoddies . . . .' . . . . . .34 ,, 25. Shoddy yarns (magn. seventy- fold) 36 26. Silk fibres . . v ." . . . . 40 27. Organzine silk .' .' 40 28. Tussah silk . . . ." 42 29. Loaded silk 42 30. Arc balance 72 ,, 31. Micrometric balance 73 , 32. Precision balance 74 XIV TABLE OF ILLUSTRATIONS. PAGE Fig. 33. Dietze's yarn balance . . -. . . . .75 34. Steel balance . . . . . . , . . 76 ,, 35. Sampling reel . . . . . . , - .77 36. ;. ... .... ... ... ... 78 37. Counting reel . . . . . . . . . 80 38. Yarn tester . . . . . . . . . .82 39. . ., . . . . ... . .;, . 82 40. Twist tester ... 90 41. ... 90 42. Heal's twist tester . . '.'.. . . J : .. . .91 43. Twist tester with expansion measurer and turn counter 92 44. Pocket instrument for testing strength of yarn . . 98 .. 4O. .. 55 55 55 )) t/O ,, 46. Breaking strain and elasticity tester . .... 98 47 and 48. Breaking strain tester . . . . ... 99 49. Elasticity tester . . . ., .' . .' . . . 100 50. Combined breaking strain and elasticity tester . . . 100 ,, 51. Breaking strain tester . . .. . . . . . 100 52. Piat and Pierrel's breaking strain tester . . ,. . 101 ,, 53. Schopper's breaking strain tester . . ... ^ , 103 ,, 54. Breaking strain and elasticity tester .,., . . . 104 55. Clamps 104 56. Holzach's continuous tester 106 57. Conditioning apparatus . . . . . . 110 58. sectional view . . . . f . 110 59. Kohl's wool conditioning apparatus ..... . 113 60. Heal's conditioning oven . . . .... ' . 114 61. Ulmann's conditioning apparatus . . . . . 115 62. Conditioning apparatus with sliding weight . :*..'> ^-^ 63. Leuner's cloth tester . . 129 64. Breaking strain and elasticity tester . , .. . 130 65. Tarnagrocki's cloth tester . . . . . . . 131 66. . . . / , ; . 133 ,, 67. Horizontal cloth tester . . ... . . 134 ,, 68. Gawalowski's waterproof tester ." .' ' , . 155 69. Cloth measuring machine . . ." ." . . 164 THE TECHNICAL TESTING OF YARNS AND TEXTILE FABRICS. YAKN TESTING. BY the term " yarn " is understood the final product of the process of spinning, or the union of textile fibres into a single thread. According to the nature of the raw material employed we may have cotton yarn, linen yarn, jute yarn, carded (wool) yarn, worsted yarn, etc., etc. Union (half wool) yarn is a mixture of wool and cotton (containing 15 per cent., or sometimes, particularly for export, as much as 50 to 60 per cent., of cotton). Vicuna yarn is a mixture of 90 per cent, and upwards of cotton with 3 to 10 per cent, of wool, and " imitation " yarn consists solely of cotton. By silk yarns, only those prepared by spinning waste silk (floret) are understood. An artificial woollen yarn may either be composed of shoddy alone or of admixtures of this material with good wool or even cotton. Yarns are classified, according to the method of their employment in weaving, as warp or weft; according to the mode of preparation, as bleached or unbleached, dyed or. undyed, printed, dressed and loaded yarn ; and by the way they are made up for use, in cops, conets, bobbins, 'hanks, or balls, etc. The union of several threads constitutes a " twist," which, 1 2 YARNS AND TEXTILE FABRICS. apart from its use as a warp in weaving, finds employment for sewing, knitting and embroidery purposes. According to the number of the threads taken, we have two-thread, three- thread twist, and so on, but it is seldom that the number exceeds eight. For cords, ropes and cables, however, several strands of twist are frequently joined together by twisting. Distinction must be drawn between the " twisted " yarn produced by tightly twisting together the individual threads, and the " doubled " yarns, consisting of slightly twisted twist. A spun thread is perfect when its diameter is regular throughout, i.e., free from knots or weak places, with the proper degree of twist and resistance to breakage, the sur- face being rough or smooth according to the material and its intended use. The examination and testing of a yarn must therefore extend to the following considerations : 1. The microscopical and chemical examination of the raw material. According to the result of this the quantitative estimation of the individual threads of mixed yarns is pro- ceeded with ; and in the case of silk, the amount of loading. 2. Determination of the " number " of the yarn. In many cases a comparison of various yarns ensures sufficient accuracy. 3. Measuring the length of yarn in the hanks, cops, bobbins, balls, etc. 4. Testing the twist of the thread. The degree of twist is a definite quantity dependent on the fineness of the yarn, the length of the fibres, and the use of the yarn (i.e., as warp or weft). In silk, the original twist of the cocoon fibre and the secondary twist are determined. 5. Examination of the external appearance of the yarn ; whether a sleek, smooth worsted yarn, or a more woolly carded yarn ; a wet or dry-spun flax yarn ; whether evenly MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 3 spun (not " tapering ") ; and whether the threads have been singed, or smoothed, or sized by machinery, etc. 6. Testing the breaking strain and stretch of a yarn. These properties, depending on the strength and length of the fibres, as well as on the degree of twist, were in the past frequently tested merely by hand, but the end is more satisfactorily attained by the use of the dynamometer. 7. A knowledge of the percentage of fat is, as a rule, de- sired only in the carded and " artificial " wool yarns. 8. Estimation of the degree of moisture (hygroscopicity). This test, up to now performed almost exclusively on silk, is latterly coming into use for wool and woollen yarns as well. I. MICEOSCOPIC EXAMINATION OF TEXTILE FIBKES. THE MICEOSCOPE : ITS PARTS, MANIPULATION AND TESTING. For examining the yarn with a view to detecting the raw materials from which it has been spun, the so-called com- pound microscope is employed. This consists principally of a tube closed at the upper end by a large, and at the lower end by a smaller, glass lens, with different focal lengths. An object may be examined under a lens in two ways : either by bringing it within or beyond the focal length of the lens. In the former case, as is seen in the simple magnify- ing glass, an enlarged picture is obtained on the side next the object ; but when the latter is at a distance greater than the focal length, the enlarged picture is formed in an in- verted position on the opposite side of the lens. In the compound microscope both these conditions are combined, for the purpose of obtaining a very high power of magnifi- cation. Of the two lenses referred to as terminating the micro- scope tube, the larger one with the greater focal length is 4 YAKNS AND TEXTILE FABRICS. placed next the eye and the smaller one of lesser focal length nearest the object. The latter is therefore termed the ob- jective and the former the eye-piece. Eye-piece and objective are fitted in a tube some six to FIG. 1. Microscope for laboratory and FIG. 2. Microscope with mi- technical purposes, with rack and pinion crometer screw fine adjust- adjustment. ment. Cylindrical substage diaphragm. seven inches in length, capable of vertical movement, and blackened on the inside to exclude extraneous light. The object is first observed at a distance greater than the focal length of the objective, which for this reason is kept very MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 5 small, whereupon an inverted magnified picture is projected at a certain distance inside the tube. At this place an annular diaphragm is inserted in the tube in order to limit the field of vision and exclude the circumferential rays tending to diminish the clearness of the picture. The length of the tube is so calculated that this picture falls within the focal length of the eye-piece at the upper end, whereby a re- enlargement of the picture is effected. The total magnifying power of a microscope is therefore the sum of the powers of the objective and the eye-piece. To ensure clearness (definition) of the picture it is advisable to produce magnification chiefly by means of the objective. The latter is, as a rule, composed of several achromatic double lenses, the eye-piece consisting of a system composed of the true ocular lens and a collecting lens, the object of the latter being to enlarge the field of vision and increase the definition of the picture, even though the size of the latter be simultaneously reduced. Were this lens not employed a portion of the rays proceeding from the picture would escape the eye-piece. The tube carrying the eye-piece and objective can be raised and lowered by the hand (though for beginners the rack and pinion motion is more certain) to regulate the coarse or approximate adjustment, whilst the fine adjust- ment is effected by the so-called micrometer screw. On the stand is fixed an arrangement for supporting the stage, as well as one for supplying the necessary light to the object under examination, viz., the substage condenser, a small circular concave reflector, movable in any direction. The stage is pierced with a small circular aperture for the passage of the reflected light, and may be either fixed or movable. The concentration of the light rays and the cutting off of the circumferential rays is effected by a re- volving metal diaphragm fitted below the stage and per- 6 YAENS AND TEXTILE FABRICS. f orated by several apertures of different diameters, their centres being equidistant from that of the diaphragm. For higher powers a cylindrical diaphragm is employed, consisting of a hollow cylinder, blackened on the inside, and affixed to the aperture in the stage. The best source of illumination is diffuse daylight with a sky evenly covered with a white veil of clouds. For evening work it is advisable to employ a glass bulb filled with a dark blue solution of ammoniacal copper oxide interposed between the source of light and the condenser. 1 A solid foundation is afforded the microscope by making the base of the stand in the shape of a horse shoe. FIG. 3. Revolving carrier (nose-piece) for two objectives to screw on to the body. When an object is to be examined by objectives of various powers in succession, use is made of a revolving objective- carrier or nose-piece screwed on to the lower end of the body tube, this arrangement facilitating the rapid change of powers. The picture produced by the microscope must be very clear at the edges ; the structural relationship of the details of the object should be well defined (analytical power), and the magnifying power must not be too low. This latter 1 Translator's Note. The various incandescent gas lights give a very good white light for microscope work. MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 7 faculty can be easily measured by observing a very fine scale (e.g., a millimetre graduated to 100 divisions) on a glass slide under the microscope. This task will, however, have already been performed by the maker of the instrument, and will be denoted in a suitable manner by means of letters and figures on the objective and eye-piece. The eye-pieces are numbered 1 to 5 : Number of eye-piece - - 1 2 3 4 5 Focal length in mm. - - 50 40 30 25 20 Magnifying power - 3 4 5-5 7 9 The objectives are marked with letters : rt l5 2 , as,aa,A,AA, B, C, D, DD, E, F, etc. The medium objectives of a focal length between 18 and 4*3 mm. are constructed with larger (indicated by double letters) or smaller apertures, the former indicating greater analytical power. The linear magnifying powers of the objectives in combi- nation with the eye-pieces are given (for a 160 mm. 6{ in. tube) in the following table : ( )hjective. Focal JljyC-pl6C6. i 2 3 4 5 >e-piece. in mm. a l 7 10 15 20 1 a-. 40 a. 11 16 23 30 35 Oft 20 30 40 50 a., 30 aa 25 35 47 60 77 aa 26 A, A A 37 50 70 90 115 A, AA 18 B 60 85 115 145 185 B 12 C 105 145 200 265 325 C 7 D, DD 175 240 325 420 540 D, DD 4-3 E 280 390 535 680 865 E 2-7 F 415 585 790 1000 1275 F 1-85 8 YABNS AND TEXTILE FABRICS. The power of each combination can thus be seen at a glance. In judging the quality of a microscope the magnifying power is not the sole consideration, the most important being the capacity of the lenses to produce a sharply defined and clear picture plainly showing all details of structure. The testing of the instrument is performed by examining sundry test objects, such as small parts of animal or vegetable organisms prepared in a suitable manner. For low powers grains of potato starch suspended in water or glycerine form a suitable test object. The individual layers of the grain arranged around the eccentric hilum must be clearly revealed in sharp, bold and delicate outline. For FIG. 4. Hyparchia janira. Scale of butterfly wing. Test object for all systems. for all systems testing higher, and the very highest powers, the wing scales of the butterfly (Hyparchia janira) and the siliceous plates of an alga (Pleurosigma angulatum) are most frequently em- ployed. (a) Hyparchia janira. The scale is rectangular in shape, with three broad points at the upper end, the surface being covered with 22 to 24 longitudinal striations. Even with a magnifying power of 300 times, a large num- ber of very delicate cross stripes can be observed between the striations. (b) Pleurosigma anaulatum. The siliceous skeleton of this alga exhibits a central ridge. The first indications of mark- MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 9 ings become apparent with a magnifying power of 200 to 250 times, and with a 300-power the markings are well defined and three systems of striation are recognisable. When the power is increased a number of laterally arranged hexagons are revealed. Supplementary Apparatus to the Microscope. For micro- scope work various additional appliances are frequently required. (a) The Dissecting Microscope. This arrangement consists FIG. 5. Pleurosigma angulatum. Test object for the analytical power of medium and high powers : 200-400 ; 400-800 times. of a stand on which is mounted a simple lens. At a distance equal to the focal lens of the glass is situated a stage for supporting the object to be dissected, which, with the as- sistance afforded by the low power lens, can be treated with small needles and knives, and prepared for examination under the large microscope. The necessary light is reflected by a small condenser below the stage. When the operator's 10 YARNS AND TEXTILE FABRICS. eyesight is good this apparatus may be dispensed with. In dissecting yarn a sheet of black glazed paper is spread on the work-table, the tiny fibres being more plainly visible and more readily seized on such a background. (b) The Camera Lucida. Various appliances have been constructed for copying microscopic pictures, by projecting the image, by means of glass prisms (Fig. 6) or reflectors (Fig. 7), on to an adjacent sheet of paper, so that the out- lines can be reproduced by pencilling. It is necessary to have the paper on a level with the microscope stage. Ap- paratus with this object have been designed by Wollaston, s. s FIG. 6. Camera lucida. Nobert, Somering and others, those in the appended illus- trations being, respectively, the camera lucida and the Abbe apparatus. To obtain pictures free from distortion it is necessary that the drawing surface should be inclined at an angle of 25 J . (c) The Micrometer. Various methods are adopted for measuring the diameters of fibres, the simplest being the glass micrometer, a fine scale engraved on glass. The measurement is performed either on the object itself (objec- tive micrometer) or on the image (ocular micrometer). The MICEOSCOPIC EXAMINATION OF TEXTILE FIBEES. 11 former consists of a glass slide on which is engraved a mil- limetre graduated into 100 equal parts, each of which is termed a micromillimetre (1 mmm., or p O'OOl mm.\ A useful form is the ocular micrometer, which consists of either an arbitrary scale or of 1 centimetre divided into 100 parts (or J cm. with 50 divisions). In the former --Sp FIG. 7. Abbe's drawing apparatus. event, the value of the scale must be ascertained by com- parison with an objective micrometer, w r hich is laid on the stage, whilst the ocular scale is inserted in the diaphragm of the eye-piece to determine how many of the divisions of the latter scale coincide with those on the former. The Polarising Apparatus. This apparatus is advisable for FIG. 8. Ocular micrometer. use in the microscopic examination and differentiation of the 12 YAENS AND TEXTILE FABRICS. various kinds of silk, and probably for vegetable fibres as well. It consists of two parts : a prism (the polariser), which is placed below the object on the stage of the microscope and allows only straight rays of polarised light to pass from the reflector through the object ; and a second prism (the ana- lyser) placed above the object preferably on top of the eye- piece and serving to analyse the rays of light transmitted through it. In employing this apparatus only very low powers are used. FIG. 9. Polariser. To be suspended in the illuminating apparatus. Making the Preparations. -Yarns to be subjected to micro- scopic examination are first of all dissected into fine fibres after removal by suitable means (referred to later) of all dirt, colouring matter, etc., so that the passage of the light will be unrestricted. It is advisable to immerse the object in water, or, better still, in a liquid like glycerine or Canada balsam, which will increase its transparency. A preliminary macera- tion of the fibres by prolonged boiling in water is very advantageous, and, in the case of vegetable fibres, boiling for a few seconds in nitric acid containing a little potassium chloride is recommended. The fibres are then laid on a glass slide (1 x 3 ins.), separated one from another, but arranged side by side, and covered with a small circular or square MICROSCOPIC EXAMINATION OF TEXTILE FIBEES. 13 cover glass (15 to 24 mm. in diameter and 0*15 to 0*20 mm. in thickness). To permanently preserve the preparation a drop of glycerine jelly is laid on the slide before applying the cover glass and warmed slightly by means of a lighted match held a little way below the cover, whereupon the liquid dis- tributes evenly, and after gently pressing down the cover glass the whole is set to cool. The edges of the cover glass are coated over with black varnish. The subsidiary instru- ments used in these operations consist of small knives (scalpels), needles, lancets, forceps and scissors. Preparing Sections. It is very often important to prepare sections in order to differentiate, for instance, between mature and immature cotton fibres, etc. To this end a number of the fibres are arranged parallel and embedded in melted tallow or paraffin, or a small bundle of the fibres can be im- pregnated with a thick solution of gum containing a little glycerine, the dried mass being firmly bound between two corks and a thin section cut by means of a smooth ground razor in a direction at right angles to the axis of the fibres. A special apparatus known as the microtome, in which the knife moves in a guide frame and cuts the preparation through at an acute angle, is also used. The small sheet of paraffin is transferred to a slide, and, after being slightly warmed, the matrix is removed by tur- pentine or benzol. If the section is not sufficiently trans- parent it is steeped in glycerine, carbolic acid, etc. The Microscopic Examination. The simplest and best ex- amination is performed by the microscope alone ; in case of doubt a microchemical test is also introduced, by admitting one or two drops of certain liquids under the cover glass and observing under the microscope the reactions ensuing thereon. In examining undyed fibres it is advisable, as already mentioned, to previously steep or boil them in water, or 14 YABNS AND TEXTILE FABRICS. if, as in the case of wool, the fibres are contaminated by adherent fat, to remove the latter by boiling with alcohol or treatment with ether, carbon bisulphide, etc. Suitable reagents for increasing the transparency should also be used. In the case of coloured fibres, the dressing and colouring matters should be removed by boiling in an alkaline or weak acid bath, or by extraction with alcohol, ether, etc. 1. VEGETABLE FIBRES. The fibres employed in industrial processes differ con- siderably in point of anatomical structure. Those belonging to the group of plant hairs are almost exclusively seed hairs, or the hairy covering of the skin of the seed. Such are : cotton, bombax fibre and vegetable silk (Asclepias). Many fibres are composed of the vascular bundles of the leaves, stems, or roots of monocotyledoiious plants, such as New Zealand flax, Manila hemp, etc. Most frequently, however, the bast fibres of dicotyledonous plants, such as hemp, flax, jute, China grass, etc., are utilised. Plant hairs exhibit (apart from branchings) only a single apex of variable shape, and always appear to be coated ex- ternally with a thin skin or cuticle, which remains undis- solved when treated with sulphuric acid. The cell walls may be thick or thin, structureless, porous, or reticulated. The chief content of the hollow interior, or lumen, consists of air. Frequently the hair is flattened in a band, so that the lumen is almost nil. The cross section is also highly characteristic. Bast fibres are composed of enclosed tubes with pointed ends, mostly with stout walls and of rounded or elongated cross section. The inner wall is often covered with a MICROSCOPIC EXAMINATION OF TEXTILE FIBEES. 15 very thin layer of strongly adherent dried protoplasm, but well-defined pores are rare. Highly characteristic are the so-called dislocations or tubercles, which, by their property of becoming more intensely coloured than the rest of the fibre when stained with iodochloride of zinc, can be readily detected. The terminals of the bast fibres are sharp pointed or blunt, simple or with branching points, thin or thick walled, etc. The subjoined table affords a survey of the length of various fibres and the ratio of length to breadth in the cells : Fibre. Length of Crude Fibres in cm. Length of the Cells in cm. Maximum Width of Cells. Extreme Limits in M- Usual Width in tL. Cotton : Sea Island (Gossy- pium barbadense) 4-05 4-05 19-227-9 25-2 Bengal (G. herba- , ceum) 1-82 1-82 11-9 22-0 18-9 Indian (G. arbo- reum) - .- . ' - 2-50 2-50 20-037-8 29-9 Flax - 20140 2-04-0 1225 16 Hemp 100300 0-84-1 1632 20 Jute - - - - 150300 0-84-1 1632 20 Nettle 8-0 16126 New Zealand Flax 80110 2-55-6 829 The chief chemical constituents of all fibres are cellulose and woody fibre, the former constituting the principal bulk, whereas the latter, which reduces the value of the fibre, 16 YAENS AND TEXTILE FABRICS. is not contained in all. Its presence is determined by the following colour tests : Aniline salts, golden yellow ; phloro- glucin and hydrochloric acid, red ; indol and hydrochloric acid, or phenol and hydrochloric acid, green ; zinc iodo- chloride, yellow to brown. Pure cellulose, such as cotton, stains blue with iodine and sulphuric acid, and violet with zinc iodochloride. The woody fibre is destroyed by bleach- ing, so that well bleached jute or hemp no longer gives the original colour reactions. Finally, the phenomena of distension and polarisation are investigated by the aid of the microscope. The vegetable fibres are distinguishable from those of animal origin by their behaviour in presence of acids and alkalis, the former being insoluble when boiled with soda or potash-lye, but readily soluble in sulphuric acid, and evolving no smell of horn when burnt. (a) COTTON. Cotton forms the seed hairs of various kinds of Gos- sypium, especially Gossypium herbaceum, G. arboreum, G. barbadense, etc. The fibre is unicellular, with variously formed apex, mostly thick walled. The diameter and length vary with the kind of cotton, the former ranging between 12 and 35 p, and the mean length from 10 to 40 mm. Under the microscope the fibre appears as a wide finely-granulated band, frequently twisted round its own axis (particularly American cotton). The cell wall being very thin, the lumen consequently appears very large, generally about two-thirds of the total breadth. In spun fibres the twists are more elongated than in the crude state. By " dead " cotton is understood such as has not at- tained full maturity. Its detection is very important, since its presence in yarn spoils the durability of the latter. It is MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 17 recognisable by the very thin transparent threads, which, though band- shaped, are not twisted, and exhibit not the slightest trace of lumen. The cross section is most highly characteristic, looking like a collapsed tube with thick walls, FIG. 10. Magnified cotton fibres : I, lumen ; d, torsion. FIG. 11. Sectional view of cotton fibres. FIG. 12. Section of " dead " or immature cotton. an appearance (Fig. 12) which it -is hardly possible to con- found with that of the mature fibre. When cotton fibre is treated with ammoniacal copper oxide it exhibits a remarkable distension, and, finally, solu- tion of the cellulose, only a ring of cuticle, or thin skin 2 18 YARNS AND TEXTILE FABRICS. covering the cell wall, being left behind. This integument is thinner in the finer varieties of cotton than in other kinds. In well-bleached fibres distension may not occur, and the skin may be altogether lacking ; in any case, a concentrated solution is necessary for the production of the first-named phenomenon. Microchemical Reactions. Iodine and sulphuric acid stain the fibre blue ; madder tincture, red ; fuchsine, red, this coloration disappearing on the addition of ammonia, and thus affording a means 'of distinguishing cotton from flax. Sulphuric acid rapidly effects solution, and concentrated soda lye causes a contraction of the internal space (mercerising). (b) FLAX, LINEN. Flax is composed of the bast fibres of the stem of the flax plant (Linum usitatissimum). Like cotton they consist of pure cellulose, are of regular thickness and average 12 to 25 //, in diameter and from 25 to 30 mm. in length. The cells are regularly built up, cylindrical in shape with nodes arranged at regular intervals. The nodes are stained more decidedly with methyl violet or more deeply when treated with zinc iodochloride. The cell wall is of constant thickness and leaves but a narrow internal channel, which therefore appears merely as a dark line and is in many cases undistinguishable. The spun fibres are mostly folded longitudinally, and the natural ends are sharp pointed and generally long drawn out. A characteristic appearance is afforded by the cross section (see Fig. 14), which exhibits a number of loosely joined, acute- angled polygons, without any yellow circumferential stain when treated with sulphuric acid, the lumen showing as a yellow spot through the protoplasm. The fibre is free from woody fibre, and swells up in ammoniacal copper oxide without dissolving completely therein. MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 19 Microchemical Reactions. Iodine and sulphuric acid give a blue stain, less quickly developed than in the case of cotton ; madder tincture, orange; fuchsine, followed by a little ammonia, gives a permanent rose coloration (distinction from cotton) ; caustic soda, faint yellow stain. Other means of detecting cotton in linen goods are afforded by : 13. Magnified flax fibres : Z, lumen ; s, apex ; v, nodes. 04 PIG. 14. Cross section of flax fibres. (a) Treating the mixture of cotton and linen with a solution of caustic potash (1:6). The flax will become more curly than the cotton, and the latter finally turns greyish white, whereas the flax is dyed orange colour (Kuhlmano method). (b) Treating the mixture with a stronger solution of caustic 20 YAENS AND TEXTILE FABRICS. potash (1 : 2) by boiling for two minutes, then washing, and drying between blotting paper. Flax becomes a deep yellow^ cotton whitish or straw colour (Bottger's method). (c) The mixture is boiled in water and then steeped in concentrated sulphuric acid for two minutes. Cotton is dissolved but linen remains white and unaltered, and can be separated by washing with a weak solution of caustic potash. (d) The mixture is boiled in water, dried, dipped for a few moments in thin, clear oil or glycerine and then pressed. Linen, by its greater capillarity, becomes transparent, whilst cotton remains opaque (Simon's method). (e) The mixture is boiled in water, dried and dipped in a strong solution of common salt and sugar, the fibres being then burned over a flame. Linen leaves a grey, cotton a black, ash (Chevalier's method). (/) The mixture is dipped in an alcoholic 1 % solution of fuchsine, washed and then laid for three minutes in am- monia. Cotton remains uncoloured, but flax is dyed rose- red (Bottger's method). (g) The mixture is dyed in an alcoholic extract of cochineal (or madder root). Cotton becomes pale red (or yellow), but flax is dyed violet (or orange, or red) (Bolley's method). (h) Cotton threads when viewed by the eye appear of regular form throughout, whereas flax threads are irregular. When quickly torn across, cotton threads curl up, but flax threads remain smooth : an accurate judgment by this means is, however, acquired only after long practice. (c) HEMP. The bast fibres of the stem of the hemp plant (Cannabis sativa) are mostly from 15 to 25 mm. long, whilst the diameter varies from 16 to 25 p. As is shown by Fig. 16 the cells are very irregular in form, being partly band-shaped and MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 21 partly cylindrical. Carefully isolated cells exhibit no parallel striations, but these are more or less decidedly apparent in the spun fibre, especially when stained with methyl violet. The lumen is mostly broad and becomes linear towards the extremity of the fibre, but the transformation is not sudden. The cell wall is not of such constant thickness as is the case FIG. 15. Magnified fibres of hemp. FIG. 16. Cross section of hemp fibres. with flax. The ends of the fibres are blunt (distinction from flax), very thick- walled, and frequently branched laterally ; cross stripes are frequently met with, but no nodes. The cross section shows the fibres attached in dense groups ; the edges are generally rounded and exhibit a yellow circum- ferential stain when heated with iodine and sulphuric acid. &2 YARNS AND TEXTILE FABRICS. The lumen, examined in cross section, is not a mere dot like in flax, but is linear, frequently branched and irregular, with- out any contents. Microchemical Reactions. Iodine and sulphuric acid give a bluish green or dirty yellow coloration ; aniline sulphate, a more or less yellow colour (faint lignification) ; hydrochloric acid, brown ; caustic potash, brown ; ammonia, faint violet ; sulphuric acid gradually dissolves the fibres ; ammoniacal copper oxide causes considerable swelling and effects partial solution. FIG. 17. Magnified nettle fibres : a, fissures in the wall ; I, lurnen. (d) NETTLE FIBRE, CHINA GRASS (Eamie). In recent times the bast fibres of the stems of various foreign nettles (Urtica) have been extensively employed. These fibres are generally 120 mm. long, the diameter ranging from 25 to 110 yu. When subjected to mechanical and chemical preparation the fibre is snow-white and highly lustrous, but unfortunately loses this property in the spinning process as at present practised. The cells are partly cylin- MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 23 drical, partly tubular; more rarely wide or band-shaped. The lumen is broad and mostly measures J to J of the entire diameter, sometimes less but rarely more. Frequently, lines are observed stretching across the cells, and a granular protoplasm is usually discernible. The cell walls are of even thickness, so that the lumen is of regular dimensions ; the extremities terminate in thick-walled rounded points and have a linear lumen. In cross section the fibres are seen to be always isolated, very large, usually elongated and com- FIG. 18. Cross section of nettle fibres. pressed flat, with, however, an open lumen frequently show- ing granular contents. Microchemical Reactions. Iodine and sulphuric acid stain blue (pure cellulose). Ammoniacal copper oxide causes great distensions but has no solvent action. Aniline sulphate induces no change. (e) JUTE. By the term jute is understood the bast fibres of the stems of several kinds of Corchorus, especially C. capsularis and C. olitorius. The crude fibre has a fine lustre and is some 140 inches long, the diameter varying between 10 and 30 p. It is usually whitish yellow in colour but turns brown after prolonged storage. The cells exhibit a somewhat remarkable structure, owing to the irregular thickness of the 254 YARNS AND TEXTILE FABRICS. cell wall, in consequence of which the internal and exterior border lines are not parallel, so that the lumen is alternately enlarged and contracted to a faint line. In commerce, however, some jute fibres are encountered which do not exhibit this variation in any remarkable degree, but a frequent interruption of the lumen is observed. The cell wall always exhibits considerable powers of refraction and therefore seems FIG. 19. Magnified jute fibres. FIG. 20. Cross section of jute fibres. to be very greatly limited by the internal space. The low tensile strength of jute, and its tendency to ravel, are attri- buted to the variable thickness of the cell walls. Microchemical Reactions. When treated with dilute chro- mic acid to which a little hydrochloric acid has been added jute turns blue ; iodine and sulphuric acid give a dark yellow MICKOSCOPIC EXAMINATION OF TEXTILE FIBRES. 25 stain ; aniline sulphate, a strong yellow coloration (therefore lignification of the fibre) ; ammoniacal copper oxide causes distension. To distinguish jute from flax and hemp the threads are warmed in a solution of nitric acid and a little potassium chromate, washed, warmed in alkaline water and washed again ; when the water is evaporated from the slide a drop of glycerine is added, and after a short time the characteristic structure of the jute will be definable. Under the polariscope (crossed Nicol prisms and dark field of vision) jute fibre shows a uniform blue or yellow colour, whereas linen or hemp is beautifully prismatic. The use of phoroglucine chloride is also advisable as a distinguishing test. Moistened with this reagent, jute stains an intense red, flax remains uncoloured and hemp is dyed a somewhat reddish tinge. This terminates the description of the chief fibres ex- tensively employed in the textile industry, but there still remain a few which are partly spun into yarn for upholstery goods, etc., but for the most part find employment in the manufacture of rope. Manila Hemp. The bast fibre of Musa textilis and other varieties comes from the East Indies and forms the best material for ropemaking. The light coloured fibres are hackled and spun into yarns which are used for making market-bags and similar weavings. Latterly the finer sorts are also used as weft for coarser upholstery goods. The fibre is from 60 to 280 inches in length, highly lustrous, smooth and even. The diameter ranges between 16 and 27 //,, of which J to J, and not infrequently as much as f to |, is occupied by the lumen. The cell is of regular structure, moderately thick and tapers gradually to a point. 26 YAKNS AND TEXTILE FABEICS. Microchemical Reactions. Iodine and sulphuric acid, golden yellow stain; caustic soda, faint yellow with slight distension ; ammoniacal copper oxide produces considerable distension, but does not dissolve the fibre. Manila hemp can be distinguished from Sisal by the colour of the ash, that of the former being greyish black, whereas Sisal leaves a white, and a mixture of the two sorts a greyish white and black ash. New Zealand Flax. The bast fibres from the leaves of Phormium tenax are worked up in New Zealand into yarn and cloth, or used in the crude state for making cord and rope. The fibres vary in diameter between 8 and 29 p, the lumen constituting J to J of this width and being of regular dimensions ; the ends are sharply pointed and the cross section circular. Cocoanut Fibre (Coir). The red-brown fibres constitute the bundles of bast tissue surrounding the hard shell of the cocoanut, and are chiefly used for making yarn mats and ropes. The bast cells are very short, being only | to 1 mm. in length.; the diameter increases regularly towards the centre, and so, in concordance therewith, does the breadth of the lumen, which occupies J to f of the width of the cell, according as the cell walls are thicker or more slender. At about the centre of the cell the inspissated layers draw to- gether, so that the internal hollow is divided. Pores are numerous. The fibre is from 12 to 20 //, in diameter, and round or oval in cross sections, the latter being of a yellow- brown colour. Cosmos Fibre. This product (first manufactured near Brussels), which appears from time to time under various, names, and has been recommended as a substitute for cotton, wool and silk, consists of manufactured residues from linen, hemp and jute. It is most frequently spun in conjunction with wool. MICKOSCOPIC EXAMINATION OF TEXTILE FIBBES. 27 2. WOOL. There are but few animals whose hairy covering finds employment in the textile industry. The largest quantity is obtained from the sheep, the yield from the Angora goat (mohair) and the alpaca playing a subordinate part. The dimensions of the wool hairs vary not only in different animals, but also in the different parts of the body of the individual. Generally, hair is tubular, frequently curly, containing an internal medullary substance, and presenting a more or less scaly appearance on the outside. Underneath the scales is a. layer of fibrous texture, frequently very faint, so that it is difficult to detect, especially when the medulla is strongly developed. The sheep produces two kinds of hair, the very curly wool and a sleek hair (beard hair), but it is only in the ordi- nary native sheep and a few rare varieties of goat that both classes are present together a long coarse upper hair and a much finer and shorter body hair (down). Otherwise the body is covered entirely, either with curly or smooth hair alone. The fineness of the hair in the higher races of sheep varies in different parts of the body, but only the curly hair is endowed with the property of felting. In the examination of wool these differences must be borne in mind. The wool consists either (a} Of pure curly wool, from the merino and allied races of sheep, such as the South Down, Hampshire Down, Electoral and Negrettir sheep ; . (b) Of pure sleek hair, e.g., from the English Cheviot (Leicester breed) ; or (c) Of a mixture of loth kinds : ordinary native wools, such as native Australian, German, Russian, South American, etc., wool. In cross section, wool is mostly circular, whereas that of 28 YAENS AND TEXTILE FABEICS. the hairs of furred animals presents the appearance of a flattened ellipse. As already indicated, three layers are distinguishable in the fibre of wool. (1) The upper layer of scales (particularly characteristic of sheep's wool), overlapping like roofing tiles, and arranged with more or less regularity, according to the fineness of the wool, surrounding the circumference to a greater or less extent, and finally either plain or exhibiting longitudinal striations, these being especially visible in wool containing no medulla. The scales show up plainly when the wool is treated with ammoniacal copper oxide or chromic acid. (2) Underneath the scales rests the true fibrous material, generally colourless but sometimes also coloured, which, in the case of shoddies from which the scales have been worn by previous treatment makes its appearance on the surface and is then characteristic (see later). (3) The medullary matter which fills the central portion of the tube and, especially in beard hairs, appears in more or less insular masses, but is lacking in the finer grades of wool. Under the microscope this matter is dark, but may be ren- dered transparent by boiling the fibre in glycerine and oil of turpentine. Chemically considered, wool consists of keratin (horny matter), but also contains, in addition to carbon, oxygen and hydrogen, about 17 % of nitrogen and 5 % of sulphur. This composition is strikingly revealed, on combustion, by the peculiar unpleasant smell of horn, which distinguishes wool from cotton. On this account the chemical reagents employed in testing wool differ considerably from those used for vegetable fibres. Boiling caustic potash or soda dissolves the fibre very readily; if acetic acid be added to this solution, sulphuretted hydrogen is evolved and a precipitate formed. Concentrated sulphuric MICKOSCOPIC EXAMINATION OF TEXTILE FIBEES. 29 acid leaves the fibre unaltered a short time, merely loosening the scales, but dissolves it fairly quickly to a reddish-brown solution on boiling ; and hydrochloric and nitric acids also dissolve wool. (a) SHEEP'S WOOL. This wool is generally white or yellow, rarely black, in colour, from 1J to 12 inches in length and between 14 and 60 FIG. 21. Magnified fibres of wool : a, merino ; b, Leicester (beard hair) ; i, medullary cells. fi in diameter, the length and fineness of staple and the form and number of the curls forming the basis of commercial classification. Sheep's wool is distinguished from all others by the quantity of scales, and these are more strongly and regularly developed in proportion to the fineness of the wool. The outer circumference is generally toothed. In the finer wools the edge of the scales extends over the whole width of the hair, and the medullary substance is lacking, whilst in coarse wools the scales are small and irregularly placed, and the medulla appears in the form of long or rounded islands. 30 YARNS AND TEXTILE FABRICS. The wool hairs are of equal diameter throughout their entire length, lamb's wool alone tapering off gradually to a point. In tanner's wool, obtained by un-hairing fells, as also in glover's wool and all wool from dead sheep, we usually find a, mixture of various classes of wool, frequently containing particles of lime as an impurity. Very often the roots of the hair are present, and are readily distinguishable by their oval form ; the wool itself is particularly brittle and is therefore only suitable for spinning along with sound wool. Microchemical Reactions. Ammoniacal copper oxide pro- duces considerable distension and Brings the scales into view. Concentrated hydrochloric acid and sulphuric acid gradually Ob FIG. 22. Cross section of wool fibres. dissolve the wool, with red coloration ; nitric acid dissolves it with difficulty, producing a yellow coloration ; and cupric or ferric sulphate dyes the wool black. (b) MOHAIR WOOL. The hair of the Angora goat has a silky lustre, is ex- tremely fine and smooth, of considerable length, and but slightly, if at all, curly. The scales, which are regular and surround the entire hair, are only discernible under very close examination. The length of the wool is from 4 to 6 inches, and the width 26 to 30 /*. The fibres appear to be free from medullary substance, except in very thick individual hairs, where it shows up decidedly in the form of a central canal occupying about one-half the entire diameter. This wool is characterised by fine, regularly arranged fissures in the fibre, which also appear as fine dots on the surface. MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 31 (c) ALPACA WOOL. The long, soft, silky hair is naturally white, grey, brown or black, 4 to 6 inches long and 20 to 34 p wide. The lustre is inferior to mohair, the scales extremely fine, or more often absent, whilst, on the other hand, longitudinal lines and small elongated islets of medullary substance are visible. This fine wool should not be confounded with alpaca shoddy. The following kinds of hair are of minor importance : Cashmere or Thibet Wool. The hair of the Cashmere goat consists of a fine soft down and a sleeker, long, beard hair, the former exhibiting scales without any medullary sub- stance, whilst the latter is very decided in the beard hairs. The down is 1J to 3 J inches long and 13 //, wide, and the hair 3| to 4| inches by 60 to 90 p. Vicuna Wool. The pure vicuna wool (which should not be confounded with the artificial product of the same name) is obtained from South America, and is rarely met with in commerce. It is very soft and delicate, of a reddish-brown colour, and resembles alpaca wool. In this case also there are two classes of hair : the fine under hair and the coarse upper or beard hair, the first-named being covered with regular scales and generally free from medulla, whilst in the latter the medullary substance is strongly developed and dark in colour, frequently divided by lighter central stripes. The edges of the scales are much less distinct than in sheep's wool. The under hair is from 10 to 20, and the upper hair about 75 //, wide. Llama Wool. The upper hair of the llama also exhibits a strongly developed insular medullary substance without any scales being detectable. In the under hair the scales are more faintly developed than in vicuna wool, but both upper 32 YAKNS AND TEXTILE FABEICS. and under hairs show longitudinal furrows. The former is 150 and the latter between 20 and 35 JJL wide. Camel Hair. The camel yields a very fine reddish or yellow-brown under hair, known in commerce as camel wool, and is used, among other purposes, for making Jager's normal cloths, the coarser hairs being employed for making carpets, coverlets, etc. Both upper and under hair exhibit faint scales, but strongly developed longitudinal FIG. 23. Camel wool. furrows. The medullary substance always appears in the upper hair, but not so decidedly as in the case of vicuna and llama hair, whereas in the under hair it is either wanting or appears, though rarely, in insulated masses. The under hair is 14 to 28 /A wide, and the upper hair 75 JJL wide. Hare and Rabbit Fur. The hairs are brown to black in colour, \ to 1 inch long, and 76 to 100 /u, wide, tapering MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 33 out to a single fine point. The medullary canal is very regular and composed of several rows of cells, so that this hair can readily be distinguished from all others under the microscope. Horse Hair. This consists almost exclusively of mane and tail hairs, chiefly white and black. The hair is very long and ranges in diameter from 90 to 250 //-, the strongly de- veloped medullary canal being highly characteristic. Cows and Calves' Hair. Cows' hair from Siberia (chiefly) is used now-a-days in the production of carpet yarns. The colours are preferably white, reddish or black, and with a dull lustre. The medullary canal occupies J to f of the total diameter. 3. ARTIFICIAL WOOLS. The " artificial " wools comprise the products elaborated from old or new wool waste, or recovered from rags, and are generally divided into three classes : 1. Shoddy is the wool recovered from old long-staple materials, such as stockings and other knitted goods, and is spun by itself as shoddy yarn. 2! Mungo is a short-staple article from milled goods, chiefly fragments of cloth, and can only be spun into yarn when mixed with longer wool or with cotton. 3. Extract 'wool or Alpaca is the name given to wool recovered from worsted rags by a chemical process known as carbonising. The fibre is mostly of short staple, arid, as a result of defective manipulation, frequently- has a cor- roded appearance when examined under the microscope. The carbonising process is effected by means of sulphuric acid, which destroys the cotton present. Whilst the foregoing particulars will facilitate the micro- scopic differentiation of all kinds of vegetable fibres, as well as silk, from wool, it is not such an easy matter to 3 34 YARNS AND TEXTILE FABRICS. determine whether the wool in yarn or cloth is a pure natural wool or artificial. Testing. A thread is prepared and examined under the microscope by a low power ; this will enable one to detect wool and silk or cotton and linen if present side by side. By now adding a drop of ammoniacal copper oxide, the silk and cotton will be immediately dissolved, the linen more slowly, and finally the wool will become slightly distended. For the second test, concentrated sulphuric acid is added, whereupon FIG. 24. Shoddies. the wool is dissolved with a reddish coloration, its composi- tion being finally ascertained by a third test. The chief characteristic test for artificial wool is the colour, which is seldom uniform under the microscope, even pure white, red or green yarns always containing fibres of different colour. Generally, coloured and plain fibres are seen side by side, the latter being either pure white or retaining a trace of their original colour. In the bette^ kinds the dyed hairs are uniform, but multicoloured in the inferior MICEOSCOPIC EXAMINATION OF TEXTILE FIBRES. 35 sorts. In this examination it is advisable to warm the sample up beforehand with hydrochloric acid, which will remove the colour due to the second dyeing and leave the original dye clearly exposed. A further confirmatory test is afforded by the ends of the fibres, these being usually unbroken in the case of natural wool, whereas in the artificial varieties they are alwaj^s torn arid ragged, the scales and medulla breaking off clean and leaving the fibrous layer in the form of a brush. Another confirmation of the presence of artificial wool is given by the absence of, or at any rate the corrosion of, scales, only traces of their existence being discoverable at the edges ; finally artificial wool is never so uniform in diameter throughout the length of the hair as natural wool, the fibre narrowing and expanding again abruptly. Professor Dr. Von Hohriel in his admirable work on the microscope structure of the textile fibres 1 gives the following as the chief factors in the detection of artificial wools : (1) Extraneous Fibres. Pure textile fabrics always consist of a single kind of fibre. In no case should a refuse wool hair be found in conjunction with merino hair ; nevertheless it may happen that stubby hairs appear, though this is no proof of an intentional admixture of inferior hair. Should several per cents, of dyed cotton be found in a material, that is a sure indication of the presence of artificial wool, for it seldom occurs that good wool is adulterated direct with cotton. Undyed cotton, unless present in any remarkable quantity, need not give rise to suspicion. (2) The length of fibre is only in individual cases proof of the presence of artificial wool ; e.g., in worsteds where the entire length of the fibre can be revealed by carefully teasing out the thread, an operation almost impossible of performance 1 Lehrbuch der Mikroskopie der Gespinnstfasern, p. 109. 36 YAENS AND TEXTILE FABKICS. in the case of milled cloths. The addition of very short fibres can be detected by brushing the sample with a stiff brush, the percentage of short waste fibres from both sides of good cloth not exceeding \ per cent. If more is produced the cloth should be more accurately examined, in which case it is advisable to specially test the waste fibres. (3) The thickness of the hair is a very unreliable indica- tion ; the more uniform the diameter of the threads in a FIG. 25. Shoddy yarns (magnified seventy-fold) : W, wool ; B, cotton ; L, linen ; S, silk ; J, jute. woollen cloth the better will the latter be ; but only when the differences of thickness are remarkably large can the presence of shoddy be suspected. (4) Histological Properties of Artificial Wool. Good wool almost invariably exhibits decided scales. On the other hand inferior wool, even on the living sheep, is deficient in scales from the tip downwards, though of otherwise normal structure. The absence of scales cannot therefore by itself MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 37 sufficiently prove the presence of artificial wool, though in fine wools they should never be lacking : so that if a merino or other fine wool be found deficient in scales this will indicate the presence of shoddies, whereas in coarse wool the circumstance would not arouse suspicion. Very curly merino wool is apparently not so easily stripped of its scales by rubbing, etc., as is the stout, stiff common wool, the individual hairs of which stand out separately from the body of the sheep. (5) The ends of the shoddy fibres, being of different form to those of natural wool, present a sure means of identification. In working up artificial wool the threads are always torn and the epidermis stripped clean off along with the medullary matter, leaving the fibrous layer projecting like a brush, especially when swollen by the aid of hydrochloric acid. If many or the most visible ends are torn shoddy is indicated (or rnungo if the fibres are short). (6) The colour is an equally important proof. Many parcels of rags are of one single colour, but for the most part they are composed of variously coloured wools, the result being that but very few shoddy samples are uniform in colour, even apparently pure white, red, yellow, or green threads actually containing fibres of other colours. Therefore if, in a yarn of any particular colour, there are found a number of individual fibres of variable, and generally very glaring colours, the presence of shoddies can be assumed with certainty. General Remarks. When a fabric or yarn is of a brownish or blackish grey, and, above all, dirty colour, and is composed of threads of all colours, it will for the most part consist of shoddy. If a material contains sheep's wool and, mostly, dyed cotton, speckled or twisted together, or contains a whole or semi- cotton warp, a large amount of shoddy will be present. Woollen goods containing vegetable fibres are rarely made 38 YARNS AND TEXTILE FABRICS. from natural wool. Shoddy yarns are, especially in winter goods, found in the under weft at the reverse side of the cloth. Such threads are generally thicker, more tightly twisted, and curlier (less smooth) than yarns from pure wool. Frequently a thick shoddy yarn is found twisted with a thin strong wool yarn. In completion of the examination of artificial wools the following tests, in addition to the microscopical, are now given : CHEMICAL EXAMINATION. (a) WATER DETERMINATION. Like all other fibres, those of artificial wool are hygro- scopic. The estimation of their water content is effected by weighing a sample in a weighing bottle and re-weighing after drying at 100 C., the operation being repeated until the weight is constant. The difference between the initial and final weights indicates the amount of water present. (b) ESTIMATION OF FAT. The dried sample is freed from fat by extraction with petroleum spirit, the fat being recovered by carefully dis- tilling the solvent, and weighed. (c) ESTIMATING THE PERCENTAGE OF COTTON. The sample from (b) is boiled for a quarter of an hour in 8 B. soda solution, whereby the wool is dissolved, leaving the cotton fibre unchanged. This residue is collected on a linen filter, and after washing with hot water until the alkaline reaction disappears, is dried and weighed. If the artificial wool contains many impurities, the sample must, before performing this estimation, be washed with slightly acidified water, and afterwards with pure water, to remove MICROSCOPIC EXAMINATION OF TEXTILE FIBRES. 39 the greater portion of the impurities which, otherwise, would have been weighed as cotton. This estimation is, however, merely an approximate one. (d) DETERMINATION OF THE ASH. This estimation is required but seldom, e.g., when it has to be determined whether the waste from cloth in process of manufacture proceeds from the shoddy used or not. In such event by estimating the ash of the waste and that of a sample of the shoddy the qualitative equality or otherwise of the results will solve the question. The operation is performed in a porcelain crucible, the sample being slowly incinerated until carbonisation ceases, and then heated to redness by the aid of the blow-pipe flame. The qualitative analysis of the residue is then performed in the usual manner. 4. SILK. Silk is the fibre with which the larvae of various insects surround themselves before entering the pupal stage, the envelope being termed a cocoon. The cocoon thread results from the hardening of the fluid ejected from the two serecteria of the larva ; hence it follows that silk exhibits no definite structure, but consists of cylindrical, sometimes flattened, or, more rarely, helical (twisted round the axis) compact threads. The colour is white, pale or dark yellow, or occasionally reddish, the colouring matter being contained in the external layer, so that when this is removed the silk is white. The different kinds of silk are distinguishable by their diametrical dimensions, and by the more or less decided appearance of longitudinal stripes, or by polarisation colours. In examining raw silk it is advisable to first boil the sample in a solution of soap. Chemically considered, silk is com- posed of three chief substances : 40 YARNS AND TEXTILE FABRICS. (1) Silk gelatin or sericin (22*5 per cent.). (2) True silk fibre or fibroin (63 per cent.). (3) Fat, resin, colouring matter, and mineral substances (about 2 per cent.). FIG. 26. Silk fibres. FIG. 27. Organzine silk. Under the microscope silk appears as a smooth (more rarely atriped) cylinder without any contents ; in contra- MICEOSCOPIC EXAMINATION OF TEXTILE FIBRES. 41 distinction to vegetable and wool fibres both lumen and scales are lacking. Mostly the silk appears as a double thread. Microchemical Reactions. The fibre dissolves with difficulty in soda and potash solutions ; sugar and sulphuric acid dissolve it with a rose-red coloration (albumin reaction), hydrochloric acid with violet coloration. It burns in the same manner as wool, but since the fibre contains no sulphur, no smell of horn is evolved : otherwise it contains all the other elements present in wool, viz., carbon, hydro- gen, oxygen and nitrogen. SILK FROM BOMBYX MORI. This insect produces the most valuable silk and the greatest bulk of the so-called " true silks ". The raw fibre is either white or yellow in colour, exhibits no structure, and is rarely striped. When treated with dilute chromic acid, the thread assumes a fine fibrous structure. The dia- meter of the fibres is at most 18 JJL. Polarisation colours are very clearly exhibited. CHAPPE SILK. This product, also known as " spun " silk, from silk- spinner's waste and from inferior cocoons, is difficult to dis- tinguish from pure silk under the microscope. According to Hohnel, it can be differentiated, with more or less accuracy, by the irregular form of the thread, and especially by the re- markable irregularity of the surrounding envelope of sericin or gum. TUSSAH SILK, also known as " wild " silk, is grey to brown in colour, and has a vitreous lustre. The fibres appear as double threads, 42 YAENS AND TEXTILE FABEICS. not, however, structureless, like true silk, but composed of a bundle of very fine fibres (fibrillse), manifested by paral- lel longitudinal stripes. Polarisation colours are but slightly FIG. 28. Tussah silk. apparent ; the diameter amounts to 52 //, maximum, the cross section is an elongated quadrilateral, and a number of fine and dense granules are displayed therein. LOADED SILK. The subjoined illustration of loaded silks is very instruc- tive, showing, as it does, that the microscope can be of good FIG. 29. Loaded silk : a, with 160/180 / ; 6, with 350/400 / loading. CHEMICAL EXAMINATION OF TEXTILE FIBRES. 43 service in detecting either low or high loading. In the latter case the thread appears to be entirely surrounded by the loading material, the rind being thicker than the fibre itself. In the case of lesser loading, it can be seen that the colour is taken up by the fibre. ARTIFICIAL SILK. In view of the considerably lower value of the artificial silks, such as are offered by Chardonnet, it becomes impor- tant that we should possess means of identifying these also. The most suitable indications are the chemical and physical characteristics ; for example, the inferior strength and elasticity of artificial silks, and their deficiency in the " crackling" feeling observable in handling true silk. When dissolved in caustic potash they produce a yellow (pure silk a colourless) solution, and they are insoluble in an alkaline solution of copper containing glycerine. 1 These properties render the quantitative separation of artificial and natural silks possible. II. CHEMICAL EXAMINATION OF TEXTILE FIBKES. The textile chemist has not always a microscope at his disposal, and he therefore has frequently to rely on chemical reactions alone. Occasionally the imitation in the laboratory of manufacturing processes (e.g., carbonisation) gives inac- curate conclusions respecting the presence of vegetable fibres in wool. The dyer knows that vegetable fibres are not coloured by the so-called acid dyes used in wool dyeing, whereas other colouring matters such as the Mikado dyes 1 Prepared by dissolving 10 grms. of cupric sulphate in 100 grms. of water,, adding 5 grms. of pure glycerine and then sufficient caustic potash to re- dissolve the precipitate first formed. 44 YARNS AND TEXTILE FABRICS. (Leonhardt) act in a converse manner. For testing for cotton and linen in a mixed cloth employment is made of fuchsine solution, followed by steeping in ammonia, which destroys the colour in the cotton fibres but leaves the linen fibres dyed a pale rose colour. By using fuchsine solution prepared according to Liebermann's directions, wool can be detected by the rose coloration in a mixture of wool and vegetable fibre. Silk and wool are separated by means of boiling hydrochloric acid, which dissolves the former, whereas the latter merely swells up without passing into solution. Persoz observed that silk dissolves readily in a 60 B. solution of basic zinc chloride, and on this circumstance a quanti- tative method was based by Renouard. A very simple and often sufficient means of distinction between wool thread and vegetable fibre consists in a combustion test, the nitrogenous and sulphurous wool fibre evolving an odour of burnt horn and leaving behind a characteristic nodule of ash, the operation being one of carbonisation rather than true combustion. On the other hand, cotton fibre burns away very quickly without the slightest smell. Further chemical examination must, how- ever, be made to ascertain whether the wool is pure or mixed with cotton, and for this purpose strong solutions of alkalis, which dissolve animal, but not vegetable, fibres, are used. The mineral acids, such as hydrochloric and sulphuric acids, behave conversely by dissolving vegetable fibres when heated but scarcely corroding those of animal origin. The preparation of the test solutions for examining textile fibres both qualitatively and quantitatively wil) now be described. (1) Ammoniacal Copper Oxide Solution, (a) Schweitzer's Method (1857). By carefully precipitating cupric dithionate with dilute ammonia, pale green basic cupric dithionate is obtained, and after filtering and washing is redissolved by CHEMICAL EXAMINATION OF TEXTILE FIBRES. 45 warming in ammonia. On cooling, crystals of ammonium dithionate separate out, leaving ammoniacal copper oxide in solution in the supernatant liquid. (6) Bottcher's Method. A glass tube, 24 x 2 inches, is loosely filled with thin rolled copper, and after being fitted at the lower end with a pinchcock, is filled with ammonia, the liquid being drawn off into a glass after a few minutes and then poured over the copper again. By proceeding in this way for several hours a deep blue liquid, thoroughly saturated with cupric oxide, is obtained. (c) Neubauers Method. A solution of cupric sulphate is precipitated by caustic soda in presence of sal ammoniac, the precipitate obtained being, after decantation and wash- ing on a filter, stored under water. The solution is prepared by adding this precipitate to an excess of ammonia so long as the latter will dissolve it, a deep blue solution being thus obtained. (d) Wiesner's Method. By covering copper turnings with a 13 to 16 per cent, solution of ammonia in an open flask. Application. The solution dissolves cellulose (cotton) with ease, and causes lignified fibres such as hemp to swell up. (2) Sodium Copper Oxide Solution. Lowe's Method. Dis- solve 16 grams cupric sulphate in 140 to 160 c.c. of water and add 8 to 10 c.c. of glycerine (sp. gr. 1*24), mixing thoroughly by agitation. Then add by drops, taking care to avoid excess, sufficient cold caustic soda to redissolve the light blue precipitate of cupric hydrate at first formed. The filtered ultramarine blue solution will keep for a long time if properly stoppered. Use. Silk fibre dissolves slowly in the very dilute, but swells up quickly in a moderately concentrated solution, and dissolves to a thick liquid when more is added. Silk dyed black by salts of iron is imperfectly and less readily 46 YARNS AND TEXTILE FABRICS. soluble. On the other hand if such silk be immersed for some time in a solution of potassium-or ammonium sul- phide, washed, and the iron sulphide removed by dilute hydrochloric acid, the solution in the sodium copper sulphate is more readily effected, and the same object can be accom- plished by a preliminary treatment with zinc and dilute hydrochloric acid. (3) Ammoniacal Nickel Solution. 25 grams of crystallised nickel sulphate are dissolved in 500 c.c. of water, and nickelous hydrate thrown down by caustic soda. After washing, the precipitate is redissolved in 125 c.c. of concen- trated ammonia and 125 c.c. of water. Use. This liquid dissolves silk immediately, but reduces the weight of linen and cotton by only 0*45 per cent, and pure wool by only 0'33 per cent. (4) Zinc Chloride Solution. According to Persoz a con- centrated solution of sp. gr. 1*7 (= 60 B.) is used. Eisner prepares a basic solution by dissolving 1000 grams of dry zinc chloride in 850 c.c. of distilled water and adding 40 parts of zinc oxide. The sp. gr. of the solution is T65. (5) Iodine Solution. Hohnel's recipe prescribes dissolving 1 gram of potassium iodide in 1000 parts of water and add- ing thereto iodine in slight excess. A more concentrated solution is prepared by dissolving 3 grams of crystallised potassium iodide in 60 c.c. of water and adding 1 gram of iodine, the resulting dark brownish red liquid being diluted, as required, by the addition of distilled water. It is advisable to prepare the solution shortly before use. The simplest way to bring about the iodine reaction in preparations under a cover glass in water is by introducing a fragment of iodine. The sulphuric acid employed in connection with this reaction consists of 3 parts of concentrated sulphuric acid, 1 part of water and 3 of concentrated glycerine. CHEMICAL EXAMINATION OF TEXTILE FIBKES. 47 (6) Fuchsine Solution. Liebermanns Method. Caustic soda or potash is added drop by drop to a saturated solution of fuchsine until the latter is decolorised, the filtered solution being then stored in a well stoppered bottle. Use. For distinguishing between undyed animal fibre and vegetable fibre. If the mixed fibre be immersed in the hot solution wool and silk will be found, on rinsing, to be dyed red, the vegetable fibres remaining uncoloured. (7) Aniline Sulphate Solution. A concentrated aqueous solution of the salt, acidified with a little sulphuric acid, is used ; or the chloride may be employed, in which event hydrochloric acid must be added in place of sulphuric acid. Use. For detecting woody tissue. (8) Phloroglucin Solution. 3 grams of phloroglucin are dissolved in 25 c.c. of alcohol and mixed with 25 c.c. of concentrated hydrochloric acid. Use. For detecting jute fibres, which it dyes an intense red, hemp and flax being merely coloured a faint rose-red. (9) Naphthol Solution. 20 parts -naphthol dissolved in 100 parts of alcohol. Use. Characteristic colorations are produced in presence of vegetable fibres. (10) Mineral Acids. Nitric acid (commercial), sulphuric acid, 58 B. strength; hydrochloric acid, 3 per cent, strength. (11) Alkalis. Soda solution, O'l per cent. ; potash solu- tion, 10 per cent. ; caustic soda solution, 7 B. (sp. gr. 1*05). The behaviour of the various fibres under the action of the several acids, bases and salts is given in the subjoined tables : 48 YARNS AND TEXTILE FABRICS. i If "I** 16 * 1 B * s CO 43 P*^ I ll 111 < -M i , , . . . , tiD ,1, , . , B'8?S 23 03 "H 43 'C "r^ ^ ' ' _g ^0 r3 C 3 i ( <1> r^ .^* += cs n < "^ P S -'5 ..-3 o d a 03 r^ 5-1 9 w CO 1 Iflf 1 1 | 8 g 3 "3 ..| | | a .2 a ^ ^ t>i >> i ^^ g ^2 8 * >>r 2 1 1 1 ^3 o 'o 02 "^ ^ _j O *JS S *s |l 1 SB M -a " . S S ^ o ^ O p^j x s Jj *> 1 a 1 i i t! w S 03 2 O ^ i d /- ^ r^ Oj 03 2 IS "*^ ,0 (S > ^ ^ CT< ^ > r^H 03 a fl O bo on >n=! > fl 1 cc 1 Hli i ; ; I. i H 3E 3 ^ "S d 45 12 S rrt 03 < > ^i c3 W fl ^ e3 bO ^ ^ o D .2 I g J'g IPJ ^> t> eg "j 1 .1 .11 '> ^^ 53 'o Sb 3 'o S s w i I ' fcO ^sa i ^5oi 11! I Hii [ i 4S o o S ^-3 ^ a o fe * " 3 - . 0) >^ 'c o-^SJ i 1 11 t 1 1 111? 1 1 ?H l> e8 C -- 1 1 *5*s d JK| 3^; O O CC -5 ti i 1^1 W ^ "*" ill II ' t ' i 2 i g 1 ||1 ^ * 5 5 ' r o r i |1| , 1 , i I &> ^3 |l_ 42 'o 1 1 1 1 1 O .2^ o ^ ^ _! o S'a' **: iL:| ^ .2 "B 3 13 ^"S i I ^2 2 OD 1 -S .2 g || ^ o g 3 1 s 1 ^ !l | *1 * | .1 J- 2 - S S^ 's .~s 3 o .2 r^ 3 cc 2 M f^ M EH CO CHEMICAL EXAMINATION OF TEXTILE FIBRES. 51 1 03 > ll II -*> > IJ I a JS1 28 o (or ammon he fibre ^> 03 B O3 _O f OJ 1 a ^ fl .2 P p o ^o a "3 fl O 52 YARNS AND TEXTILE FABEICS. QUALITATIVE AND QUANTITATIVE ESTIMATIONS. (a) Detection of Vegetable Fibres in Presence of Animal Fibres. 1 The following method is based on the formation of sugar when cellulose is treated with acids. The sample must be thoroughly boiled with water in order to extract the " dress- ing ". When this is done, about 0*1 gram is put in a test glass with 1 c.c. of water and two drops of an alcoholic solu- tion (15-20 per cent.) of o-naphthol, and as much concentrated sulphuric acid as there is liquid already. Vegetable fibres, if present, are readily dissolved, and the liquid assumes a deep violet colour when agitated ; wool or silk gives a more or less yellow to reddish-brown coloration. Thymol pro- duces a beautiful red coloration. (b) Separation of Wool from Cotton. The dressing and colour being removed by boiling the sample in dilute hydro- chloric acid, dilute lye, or by extraction with alcohol, ether, etc., a weighed portion is dried at 100 C., and placed in 4 parts of sulphuric acid and 1 part of water for twelve hours, then mixed with three volumes of absolute alcohol and water and filtered. The residue is washed in absolute alcohol until the washings are colourless, and afterwards with water, being finally dried and weighed to ascertain the weight of wool present. (c) Separation of Wool from Cotton. After freeing the sample from dye and dressing as before, and washing, a portion is dried and weighed, being then immersed in am- moniacal copper oxide for twenty minutes, after which water is added. The residue left after filtration is thoroughly washed, dried and weighed, the result giving the amount of wool in the mixture. (d) Separation of Cotton from Wool. The cleaned, dried and weighed sample is gently boiled for two hours in 8 B. 1 Dingler's Polyt. Journal, vol. cclvi., p. 135. CHEMICAL EXAMINATION OF TEXTILE FIBRES. 53 caustic potash, then well washed and re-dried. During the boiling a few drops of water are added from time to time to prevent the alkali becoming too concentrated. After drying at 100 C. the residue is weighed, the result giving the weight of cotton and the loss that of the wool. Instead of potash, 7 B. caustic soda may be used, boiling being restricted to a quarter of an hour. (e) Separation of Silk and Wool. These fibres may be separated by boiling in hydrochloric acid, in which the silk is readily soluble, whilst the wool merely swells up. (/) Separation of Silk, Cotton and Wool.-M.teY removing the dressing and dye, as already described, the sample is treated with ammoniacal nickel oxide, which dissolves the silk at once. The cotton is then dissolved out by means of ammoniacal copper oxide, leaving the wool behind. The treatment may also be varied by boiling the sample for two to three minutes in 1 per cent, hydrochloric acid, after the removal of the nickel solution, and then washing and weigh- ing. The cotton and wool are separated by boiling in a 2 per cent, soda lye, the residue (wool) being rinsed, dried and weighed. (a) Separation of Silk, Cotton and Wool (Remontfs Method}. Two samples of yarn, each weighing 2 grams, are dried, weighed and boiled for a quarter to half an hour in 200 c.c. of 3 B. hydrochloric acid, to remove the dressing, and are then thoroughly washed and pressed. One sample is immersed in a boiling solution of basic zinc chloride, for a very short time, then washed thoroughly, first in acidified, afterwards in clean, water, and dried. The loss in weight gives the amount of silk. The second sample is boiled for fifteen minutes in 60 to 80 c.c. of caustic soda (sp. gr. 1'02), and then washed and dried, the loss in weight representing the proportion of wool. The residue is cotton, the dry weight of which must 54 YARNS AND TEXTILE FABRICS. be augmented by about 5 per cent, to compensate for the corrosion of the fibre during the operation. (h) Separation of True Silk, Tussah Silk, Wool and Cotton. The mixture is at first acted on by boiling half a minute with concentrated hydrochloric acid, which immediately dissolves the true silk, the tussah silk being dissolved at the end of two minutes' further boiling. On treating the residue with hot caustic potash the wool is dissolved, and the cotton left behind by itself. Hohnel J recommends the following method for dis- tinguishing between true and wild silk : A saturated solu- tion of chromic acid is diluted with an equal bulk of water, and if pure silk be immersed in this solution and boiled for a minute, the fibre will completely dissolve, whereas tussah silk is barely attacked at all, even when the boil- ing is prolonged to two or three minutes. Wool behaves similarly to true silk. A weak solution of zinc chloride 45 B., or sp. gr. T45 attacks true silk very rapidly, but acts on tussah silk only after longer exposure, so that this solution also may be used for distinguishing and separating them. (i) Detection of Flax and Cotton. The sample threads are dyed by immersion in alcoholic fuchsine solution (1 gram fuchsine in 100 c.c. alcohol), then washed with clean water until the colour ceases to run, and steeped in ammonia for about three minutes. The linen threads will be dyed rose colour, whereas the cotton threads will be decolorised. For the purposes of quantitative separation the samples, previously freed from colour and dressing, by a suitable boiling in dilute hydrochloric acid or distilled water, followed by a thorough rinsing, are dipped for one and a half or two minutes in concentrated (66 B.) sulphuric acid, then rinsed out well, rubbed between the fingers and 1 Hohnel, MikrosUopie , p. 150. CHEMICAL EXAMINATION OF TEXTILE FIBRES. 55 neutralised by steeping in dilute ammonia or sodium carbonate solution. After washing over again in water the threads are pressed between blotting-paper and dried, when linen threads will, as a rule, be found to have re- tained their structure whilst the cotton has dissolved after passing through a gelatinous stage in which it will tear like tinder. QUANTITATIVE ESTIMATION OF THE LOADING OF SILK. In testing silk the question of the nature and quantity of loading present has always to be solved, so the matter will now be briefly discussed. Following the directions given by E. Konigs, manager of the Silk Conditioning Institution at Crefeld, the first thing to do is to determine the percentage of water in the silk ; then the fat, by extraction with ether ; and afterwards the gummy integument, by boiling in water. From the residue the Berlin blue is extracted by alkalis, re- precipitated by acids, and the filtered precipitate calcined with repeated additions of nitric acid. Each part of the ferric oxide so obtained corresponds to 1*5 parts of Berlin blue. Any stannic oxide present is also determined and calculated as stannic catechutannate, 3*33 parts of which are the equivalent of 1 part of oxide. The total amount of ferric oxide is likewise ascertained and deduction made of the quantity present in the form of Berlin blue and that (0'4 per cent., or 0*7 per cent, in raw silk) existing in the silk, the residue representing the ferric oxide in combination with the tannic acid from catechu or chestnut extract, 1 part of this oxide corresponding to 7*2 parts of ferric tannate. Should ferrous compounds of this nature be present the multiplying factor will be 51 instead of 7*2. According to Moyret, loaded silk is examined as follows : (a) Moisture Determination. In the absence of a condition- 5(5 YARNS AND TEXTILE FABRICS. ing apparatus it will be sufficient to dry 10 grams of silk on an oil bath at 120 to 130 C. and estimate the water by the ensuing loss in weight. If this loss exceeds 15 per cent, it may be assumed that the silk has been loaded with hygroscopic substances. (b) Soluble Loadings. The dried silk is boiled in distilled water, rinsed, dried and weighed. Glycerine, sugar, mag- nesium sulphate, potassium sulphate, etc., will pass into solution. (c) Benzol, or Ethereal Extract. The silk, thoroughly washed and dried, is extracted with ether and weighed. The ex- tract, being evaporated and examined, will reveal the cause of rancidity in the silk from the use of bad oils and soaps. (d) Action of Hydrochloric Acid. The sample of silk is treated for J hour at 30 to 40 C. with dilute (1 : 2) hydro- chloric acid. If ferric tannate has been used for loading, the reddish-yellow silk will be decolorised, and the liquid will turn a dirty brown colour, which does not become violet on addition of lime water. Should the reddish solution turn violet in presence of this reagent, logwood is indicated, and if the fibre is dark green and the liquid yellow and unchanged by lime water, then Berlin blue may be assumed. When the fibre is green and the liquid red, changing to violet when lime water is added, this indicates logwood black dyed on a ground of Berlin blue. The iron, chrome and alumina mordants must be tested for in the liquid. (e) Action of A Ikalis. After the silk has been treated as above it is boiled in an alkali solution, to dissolve the tannin, which may be detected by precipitation with iron salts. (/) Determination of Ash. A weighed sample is incine- rated in a platinum crucible and calcined. If the weight is more than 1 per cent, of the original the silk has been loaded and the ash should then be further examined. DETERMINING THE YARN NUMBER. 57 (g] Determination of the Dye Stuff. The dye stuffs most in vogue are detected by the hydrochloric acid treatment. The further consideration of this point will be resumed later. III. DETEEMINING THE YAEN NUMBEE. In comparing yarns together their thickness is employed as a means of classification, one being " coarse," another "medium," a third "fine" and soon. This method of de- scription is, however, inexact, and it is preferable to make a comparison with a collection of standard "numbers" of yarn, by the aid of which it is easy, after a little practice, to quickly identify the number of the yarn under examination. More accurate comparison is then made by twisting the sample with the standard sample, whereby it becomes evident to a moderately good eye whether the two are of equal thickness or no. The determination of the fineness of a yarn in figures is based upon either (1) A Definite Length of Yarn. The various weights of this standard length are designated yarn numbers. This method of procedure is followed, as described below, in the case of silk, where the unit adopted is 9600 aunes (= 11,400 metres, or 12,46 7'4 yards), which length being weighed gives the number of the yarn. (2) A Constant Weight. In this case the various lengths required to make up this weight form the yarn numbers. This is the method pursued for all other textile fibres, e.g., cotton, wool, chappe silk, etc. Of course the numbers will vary according to the system of weights adopted; for example, if the metric system is used we have metric yarn numbers, or if English weights, the English system of numbers. For numbering purposes a certain length of yarn is wound on a reel of definite circumference, from which it is 58 YARNS AND TEXTILE FABRICS. removed as hanks. These are divided into " lays " (or "leas") by means of a tie thread, each "lay" consisting of a fixed number of threads, i.e., turns on the reel. Each thread is the same length as the circumference of the reel, and, when multiplied by the number of turns in the lay and the result by the number of lays in the hank, gives the exact length of yarn in the latter. For a number of years attempts have been made to introduce a uniform system of numbering yarns but hitherto without success. In the metric system of numeration the number of the yarn denotes the number of metres that go to a gram, or kilometres to a kilogram, the length of the thread being fixed as 1000 metres with decimal sub-divisions. The following variations above and below the exact standard representing the number of the yarn are allowed: 1. Cotton yarns Nos. 1 to 10 English 2*5 per cent. Waste yarn, including so-called "imitation " yarns, up to No. 6 - - 4-0 Cotton yarns Nos. 11 to 20 . - - ... 2-0 21 to 40 - - - - . 2-5 above No. 40 - - - - - - 3'0 2. Worsted yarn - - - - - - - - ' - 1-5 3. Carded yarn ...... - - - - 2-5 ,, Shoddy from wool 4-0 ,, 4. Mixed wool and cotton yarn - - --..;.. . . 2'5 wool and silk 1'5 ,, 5. Linen yarn -'- .- 2'5 6. Jute yarn - - -'....- 3-0 In determining the number of bleached linen yarn, the loss in bleaching is fixed at '20 per cent, for J, 18 per cent, for f, and 15 per cent, for J bleaching. 1. COTTON. (a) Metric Numbers. In. this system the number of a cotton yarn indicates the number of times 1000 metres (1093'63 yds.) or m / m required to make up a standard weight DETERMINING THE YARN NUMBER. 59 of 500 grams (1'102 Ibs.). For example, No. 20 cotton yarn is one, 20,000 metres (21,872*66 yds.) of which weigh 500 grams, or i- kilo. The following table gives the weight, in grams, of 1000 metres of the various numbers : No. Weight in Grains. No. Weight in Grams. N Weight in Grams. No. Weight in Grams. N I Weight ' in Grams. 1 500 15 33-333 29 17-241 43 11-628 1 85 5-822 2 250 16 31-250 30 16-667 44 11-364 90 5-556 3 166-667 17 29-412 31 16-129 45 11-111 95 5-263 4 125 18 27-778 32 15-625 46 10-869 100 5 5 100 19 26-316 33 15-152 47' 10-638 110 : 4-545 6 83-333 20 25 34 14-706 48 10-417 120 4-167 7 71-429 21 23-809 35 14-286 49 10-204 130 3-846 8 62-500 22 22-727 36 13-889 50 10 140 : 3-571 9 55-556 23 21-739 37 13-514 55 9-091 150 3-333 10 50 24 20-833 38 13-158 60 8-333 160 i 3-125 11 45-455 25 20 39 ! 12-821 65 7-692 170 ' 2-941 12 41-667 26 19-231 40 12-500 70 7-143 180 2-778 13 38-462 27 18-519 41 12-195 75 6-667 190 2-631 14 35-714 28 17-857 42 11-905 80 6-250 200 2-500 i The product of the number and weight is always the same, i.e., 500, and the weight of the consecutive numbers diminishes considerably at first, but afterwards in descending ratio, and almost inappreciably in the finest numbers. The following general rules are therefore applicable to the deter- mination of the weight and length of the threads : (a) The number of the yarn is obtained by dividing the length by twice the weight, e.g. : What is the number of a thread 60 metres of which weigh 5 grams ? Answer : 6. 60 60 Calculation =3^ = ^= 6. (#) Given the length and number of a thread, the weight is calculated by dividing the former by twice the latter, e.g. ; What is the weight of 80 metres of No. 4 yarn ? Answer : 10 grams. Calculation : 80 2x4 = 10. 60 YARNS AND TEXTILE FABRICS. (7) The length of a thread is found by doubling the pro- duct of the number and weight, e.g. : How long is a No. 12 thread weighing 5 grams ? Answer : 120 metres. Calculation : 2 x 12 x 5 = 120 metres. (6) English Numbers. This system is in use not only in England but, almost without exception, also throughout the whole of Germany and Switzerland. By an English yarn number is understood the number of hanks that go to an English Ib. (453 grams). Circumference of reel = lj yds. (1 yd. = 0'914 metre). 1 hank of 7 lays, of 80 turns, of 1J yds. each = 840 yds. (768 m.\ An English yarn No. 20 is therefore one of which 20 x 840, or 16,800 yds. (15,360 m.) weigh 1 Ib. TABLE OF THE WEIGHT OF 1000 METRES (1096 YARDS) OF COTTON YARN IN VARIOUS (ENGLISH) NUMBERS. 1 Nt>. Weight in Grams. No. Weight in Grams. No. Weight in Grams. No. Weight in Grams. 4 1476 12 492 20 295 36 164 6 984 14 422 24 246 40 147 8 738 16 369 28 211 44 134 10 590 18 328 32 184 50 118 1 Table of length in yards per Ib.. and weight per 1000 yards in ounces of English yarn numbers. No. Yards per Lb. Weight per 1000 Yds. No. Yards per Lb. Weight per 1000 Yds. Nn ! Yards No - per Lb. Weight per 1000 Yds. | 4 3360 4-76 oz. 16 13,440 1-19 oz. 1 36 30,240 0-517 oz. 6 5040 3-18 , 18 15,120 1-065 , 40 i 33,600 0-476 8 6720 2-38 , 20 16,800 0-952 , 44 36,960 0-433 10 8400 1-90 , 24 20,160 0-795 , 50 42,000 0-380 12 10,080 1-59 , 28 23,520 0-695 , 14 11,760 1-39 , 32 26,880 0-595 , DETERMINING THE YARN NUMBER. 61 The finest number of cotton yarn is No. 240, higher num- bers being rarely met with in commerce. The utmost spinning capacity is about No. 300, of which 300x840 = 252,000 yards (230,400 m.) go to the Ib. Beyond 20 the even numbers only are in use 24, 26, 28,. 30, and so on ; in the finest yarns the numbers rise by 5 and in those above 100 by 10 ; Nos. 6 and 8 are the coarsest yarns. For lamp wicks Nos. \ to 2 ; for tallow candles, mule yarns Nos. 8 to 12 ; for wax and stearin candles Nos. 20 to 40, and for woven hollow lamp wicks Nos. 12 to 30' are used. Yarns for hosiery knitting range from 6 to 36, and mule yarns 80 to 90 are also employed. The following particulars will facilitate comparison of the English and metric systems of numbering : The French number = '847 X English No.; the Inter- national No. = 0'423 x English No. ; the English No. = 1*18 x French No. ; the International No. =0*5 X French No. It therefore follows that when a French number is com- pared with the English number of the same numerical value the former is finer than the latter (see following tables). (a) COMPARATIVE TABLE OF ENGLISH, FRENCH AND INTERNATIONAL NUMBERS FOR COTTON YARNS. "& French No. Intl. No. Engl. No. French No. Intl. No. Engl. No. French No. Intl. No. 1 = 0-85 = 0-42 26 = 22-02 = 11-01 60 = 50-82 = 25-41 2 - 1-69 = 0-85 28 = 23-72 = 11-86 62 = 52-51 = 26-25 2-54 = 1-27 30 = 25-41 = 12-7 64 = 54-21 = 27-1 4 = 3-39 i = 1-69 32 = 27-10 = 13-55 66 = 55-90 = 27-95 5 = 4-24 ! = 2-12 34 = 28-8 = 14-4 68 = 57-60 = 28-8 6 = 5-08 ; = 2-54 36 = 30-49 = 15-25 70 = 59-29 = 29-65 7 = 5-93 = 2-96 38 = 32-19 = 16-1 75 = 63-53 = 31-76- 8 = 6-78 - = 3-39 40 = 33-88 = 16-94 80 = 67-76 = 33-88 9 = 7-62 = 3-81 42 = 35-57 = 17-79 85 = 72 = 36- 10 = 8-47 = 4-23 44 = 37-27 = 18-63 90 = 76-23 = 38-11 12 = 10-16 = 5-08 46 = 38-96 = 19-48 95 = 80-47 = 40-23 14 = 11-86 = 5-93 48 = 40-66 = 20-33 100 = 84-7 = 42-35 16 = 13-55 = 6-77 50 = 42-35 = 21-18 110 = 93-14 = 46-57 18 ' = 15-25 = 7-62 52 = 44-04 = 22-02 120 = 101-64 = 50-82 20 = 16-94 = 8-47 54 = 45-74 = 22-87 130 = 110-11 = 55-5 22 = 18-63 = 9-31 56 = 47-43 = 23-76 140 = 118-58 = 59-29 24 = 20-33 = 10-16 58 = 49-13 = 24-56 62 YAKNS AND TEXTILE FABEICS. (6) COMPARATIVE TABLE OF FRENCH AND ENGLISH YARN NUMBERS. French. Engl. French. Engl. French. Engl. French. Engl. 1 1-18 11 12-10 21 24-8 32 37-8 2 2-23 12 14-2 22 26-0 34 40-1 3 3-54 13 15-3 23 27-2 36 42-5 4 4-72 14 16-5 24 28-3 38 44-8 5 5-90 15 17-7 25 29-5 40 47-2 6 7-8 16 18-9 26 30-7 45 52-1 7 8-26 17 20-1 27 31-8 50 i 59-0 8 9-44 18 21-2 28 33-0 55 64-9 9 10-62 19 22-4 29 34-2 60 70-8 10 11-80 20 23-6 30 35-4 Doubled yarns are counted in the same way as singles, but the number of threads is given as well, e.g., for two-ply 40 / 2 , three-ply W / B , etc. In the process of doubling the yarns lose from 2J to 6 per cent, of their length, according to the number of threads, and become correspondingly thicker. Yarns of more than two-ply are also known as sewing twist (cordonnet) and cord. A dyed, singed and finished twist is also termed lustred yarn (eisengarn). 2. LINEN YARNS. These are divided into hand-spun and machine-spun yarns. The length and sub-division of the hanks of the former class are arranged according to greatly differing systems in different countries, but the latter are for the most part reckoned in commerce according to the Anglo-Irish system. Circumference of reel = 2J yds. 1 spindle, of 2 hasps, of 2 hanks, of 12 cuts (or leas), of 120 threads, of 2J yds. each = 14,400 yds. (13,167 m.). English System : 1 threescore, of 12 bundles, of 5 hasps, of 4 hanks, of 10 leas, of 120 threads, of 2J yds. = 720,000 yds. (656,640 m.). This system is also in use in the linen districts of Westphalia, Silesia and Saxony. DETEKMINING THE YARN NUMBER. 63 The yarn number is expressed by the figure indicating the number of leas that go to an English Ib. ; so that, since the length of a lea is exactly 300 yards, the length of yarn going to a Ib. is found by multiplying the yarn number by 300. The numbers of linen yarns differ in comparison with those of cotton yarns because the hank of cotton measures 840 yds. whilst the length of linen cuts is 300 yds. To obtain the cotton yarn number corresponding to a linen yarn number the latter is divided by 2*8, i.e., linen yarn No. 28 is the equivalent of cotton yarn No. 10. These numbers, how- ever, represent yarns of very different appearance, the linen looking the finer. Linen yarns are characterised as dry or wet-spun according to the method of spinning pursued. The former are possessed of a greater degree of firmness, whilst higher numbers can be obtained by wet spinning, both kinds being easily recognised by their appearance. The tow yarns, prepared from the waste in flax spinning, are very easily distinguished from linen yarn, by the numerous knots, due to contained particles of shives, which they exhibit and from which linen yarns are free. In Germany flax is dry-spun to Nos. 10 to 30 yarns, and wet-spun up to No. 80 ; in Belgium and Scotland up to No. 200. Tow yarns are dry-spun from Nos. 6 to 20, and wet-spun up to No. 35, these latter yarns being used as warp for low-class fabrics, and when loosely spun and bleached, as wefts for J-linens. Hand-spun yarn differs from machine-spun, in handling more supple and smoother, more elastic, uneven and less rounded in form and by not rolling up, whilst machine-spun yarn feels stiffer and rougher, is of regular thickness and perfectly round. Twist or " sewing " is the name given to yarn prepared OF THE UNIVERSITY 64 YAENS AND TEXTILE FABEICS. by twisting together two or more threads. English and Scotch twists are particularly firm and of fine appearance. The chief kinds are two and three-ply from Nos. 30 to 300 yarns ; lacing twist, two and three-ply from Nos. 50 to 200 yarns ; cord, three and four-ply twist from Nos. 25 to 80 yarns. Of the other systems of numbering linen yarns in use, may be mentioned : The Austrian Reel: 1 schock, of 12 bundles, of 20 hanks (strahn), of 30 leas (gebind), of 40 hasps (stuck), of 3 Vienna ells (ellen) = 864,000 Vienna ells. A hank, therefore, contains 3600 Vienna ells (1 Vienna ell = 0'77921 m. or 30-67749 inches). The yarn number indicates the number of hanks per 10 English Ibs. (8' 1 Viennese pounds). The French Reel (partly used in Belgium) : 1 shock, of 12 bundles, of 50,000 metres = 500,000 metres (546,816 yds.). Circumference of reel, 2| metres (2'734 yds.). The yarn number gives the number of times 1000 metres (1096 yds.) going to J kilo. (1'102 Ibs.). 3. JUTE YARNS. Three hundred yards (274'3 m.) are wound to a lea, the number of which in 1 Ib. forms the yarn number. This English system of flax numbers is used in commerce, but in the factories where spinning and weaving are carried on together the so-called Scotch system is in vogue, based on a constant length (spindle) of 14,400 yds. (13,161 m.), the number of Ibs. weighed by this unit being the yarn number. (a) English Numbers. In England and Germany the bundle of 60,000 yds. (54,863 m.) is taken as basis. The reel circumference (thread) is 2J yds. ; 15 to 120 threads form a lea; 5 leas = l hank; 20 hanks = 1 reel; 16 to 20 reels = 1 bundle. DETERMINING THE YARN NUMBER. 65 The yarns : No. J: 1 lea = 15 threads, 1 hank = 187'5 yds., 1 reel- 3750 yds. Nos. i-| : 1 lea = 30 threads, 1 hank = 375 yds., 1 reel = 7500 yds. Nos. 1-li : 1 lea = 60 threads, 1 hank = 750 yds., 1 reel = 15,000 yds. Nos. 1J-12: 1 lea = 120 threads, 1 hank =1500 yds., 1 reel = 30,000 yds. So that No. J contains in the bundle 16 reels, 320 hanks, 1600 leas, 24,000 threads = 60, 000 yds. Nos. J-J contain per bundle 8 reels, 160 hanks, 800 leas, 24,000 threads = 60,000 yds. Nos. 1-1 J Per bundle, 4 reels, 80 hanks, 400 leas, 24,000 threads = 60,000 yds. Nos. 1J-12 Per bundle, 2 reels, 40 hanks, 200 leas, 24,000 threads = 60,000 yds. (&) Scotch Numbering. 1 spindle = 8 hanks = 48 leas = 5760 threads = 14,400 yds., or 1 spindle of 8 hanks, of 6 leas, of 120 threads, of 2J yds. = 14,400 yds. As in the case of linens, a distinction is drawn between jute line and jute tow yarns, the former being spun in Nos. 12 to 24, the coarser numbers from No. J onwards in tow yarns only. In Holland the fineness of jute yarns is given by a number denoting the number of hectograms (1 h.g. = 0*22 lb.), weight per length of 150 metres (164'4 yds.). 4. KAMIE, NETTLE FIBRE. These yarns are numbered like chappe silk, the number denoting the number of times 1000 metres of the yarn required to weigh 1 kilo. In fineness nettle yarn No. 18 equals linen yarn No. 30 and cotton yarn No. 11 (water), 66 YAKNS AND TEXTILE FABRICS. and is therefore heavier than the corresponding cotton, but lighter than the linen thread of the same number. This fibre is spun up to No. 250. 5. WOOL. Woollen yarns are divided into single and doubled yarns ; and, further, according to the kind of wool and method of spinning into carded and combed (worsted) yarns. Attempts have been made to introduce a uniform metric system of numbering both kinds, but up to the present this has succeeded in the latter class only, carded yarn being still numbered according to separate standards in different countries. Thus we have English, French, Dutch, Saxon, Bohemian, etc., standards. Formerly in Austria and Germany combed yarns were reeled in the same manner as English cottons. (a) Metric or International System. 1 hank =10 leas = 730 threads = 1000 metres (10,936 yds.), or 1 hank = 10 leas = 800 threads = 1000 metres, according as the reel measures 1*37 (53| in.), or 1*25 (49 J in.) metres in circumference. The yarn number denotes the number of times 1000 metres ( m /m) going to 1 kilogram, e.g., No. 4 measures 40,000 metres per kilo. From this definition it follows, therefore, that, thickness for thickness, the woollen yarn number is double that of the cotton yarn number, e.g., No. 40 woollen corresponds to No. 20 cotton yarn. The following rules are generally applicable : (a) The weight, of 1000 m. of yarn is found by dividing the number into 1000. (/3) To find the number of a thread the weight is divided into 1000. (7) The length of a thread is equal to the product of the weight and yarn number. To determine the weight of any given number, the table DETEEMINING THE YARN NUMBEE. 67 given on p. 59 may be employed, except that the weight stated therein must be multiplied by 2, or else the weight of the number forming one half of the given number is taken, e.g., to find the weight of 1000 m. of No. 20 wool the weight given in the table must be multiplied by 2, or else the number (20) must be divided by 2, i.e., the weight of No. 10 cotton is the one sought. (6) English System. 1 hank = 7 leas = 560 threads = 560 yds. (512 metres). This embodies the same basis as the cotton yarn system, viz., the Ib. as the unit of weight and the hank of 560 yds. as that of length. This length is termed a " conet," so that the yarn number represents the number of conets going to 1 Ib. The reel is 1J yds. round. (c) Prussian System : (a) 1 hasp (stuck) =4 hanks (zahlen) = 880 threads = 2200 Berlin ells = 1467 m. (1604'35 yds.). Keel circumference : 2J Berlin ells = 1*666 m. (65 \ ins.). () 1 hasp = 20 leas (litzen) = 880 threads = 2150 Berlin ells = 1434 m. (1568J yds.). Keel circumference : 2*44 Berlin ells = 1*63 m. (64'17 ins.). This is the Netherland system of reeling : in the Kheriisl i cloth works the following systems are preferred : (7) 1 hasp = 10 leas = 1000 threads = 2000 Brabant ells = 1390 m. (1520-15 yds.). Keel circumference : 2 Brabant ells = l'39 m. (54f ins.). (8) CockeriWs reel (also in use in Belgium) : 1 hasp = 2240 Berlin ells = 1494 m. (1634 yds.). The number indicates the number of hasps (stuck) going to 1 " zollpfund" of 500 grams (1102 Ibs. Engl.), Nos. 2, 3, 4, etc., representing so many 2200 Berlin ell (or 2000 Brabant ell) lengths. (d) Saxon System : (a) 1 hank (zahl) = 5 leas (gebind) = 400 threads (faden) = 800 Leipzig ells = 452 m. (494'3 yds.). 68 YAENS AND TEXTILE FABRICS. Keel circumference : 2 Leipzig ells = 1*1 33 m. (44 '6 ins.). (0) 1 hank = 4 leas = 320 threads = 800 Leipzig ells = 452 m. (494'3 yds.). Reel circumference : 2J Leipzig ells = 1*412 m. (55 J ins.). (7) 1 hank = 5 leas = 400 threads = 1200 Leipzig ells = 678 m. (741J yds.). Reel circumference : 3 Leipzig ells = 1*695 m. (67 ins.). (8) 1 hasp (stuck) = 4 hanks = 12 leas = 2400 Leipzig ells = 1356 m. (1483 yds.). (e) 1 hasp = 2200 Leipzig ells = 1243 m. (1359-4 yds.). The number indicates the number of hasps (hanks) per i kilo. (e) Viennese System (current in Austria) : 1 hank (strahn) = 20 leas (klapp)=880 threads (faden) = 1760 Vienna ells = 1371 m. (1499-4 yds.). Reel circumference : 2 Vienna ells = 1*558 in. (61*16 ins.). The number indicates the number of hanks per Viennese Ib. of 560 grams (1-234 lb.). In Bohemia 1 hank of 800 Leipzig ells is frequently taken as the standard of reeling, the number being based on the English lb. of 453 grams. Reel circumference : 2 Leipzig ells. (f) French System : (a) Sedan and Neighbourhood : 1 hank (echevau) = 22 leas (macque) = 968 threads = 1493*6 m. (1633-45 yds.). Reel circumference : 1*543 m. (60 J ins.). The number indicates the number of hanks per J kilo. {/3} Elbceuf: 1 hank = 3600 m. (39371 yds.). Reel circumference : 2 m. (78'74 ins.). The number gives the number of hanks per |- kilo. The following method is employed for converting the numbers of one system into those of another : DETEEMINING THE YAEN NUMBER. 69 From the metric number is found by multiplying The metric number is found by multiplying by 0-34 The Prussian number by 2-93 1-11 Saxon M 0-90 0-41 ,, Austrian ,, 2-45 0-88 ,, English ,, 1-13 0-14 ,, Elboeuf 7-20 0-33 ,, Sedan . i. 3-05 TABLE COMPAEING THE METEIC NUMBEES FOE CAEDED WOOL WITH THE SEVEEAL OLDEE NUMBEES. .8 l| 1 1 i a | G cfi g "S g "bless s * 1 M 1 J5 ^g II CD o PQ a o O QQ 3 5 4-43 2-04 4-13 2-76 1-74 1-67 1-64 0-69 6 5-31 2-45 4-96 3-31 2-09 2-01 1-97 0-83 8 7-09 3-26 6-62 4-41 2-79 2-68 2-62 1-11 10 8-86 4-08 8-27 5-51 3-49 3-35 3-28 1-39 12 10-60 4-90 9-92 6-61 4-19 4-02 3-94 1-67 15 13-3 6-12 12-4 8-27 5-23 5-02 4-92 2-08 20 17-7 816 16-5 11-0 6-97 6-69 6-56 2-78 25 22-2 10-2 20-7 13-8 8-71 8-36 8-20 3-47 30 26-6 12-2 24-8 16-5 10-4 10-0 8-83 4-17 40 35-4 16-3 33-1 22-1 13*9 13-4 13-1 5-56 50 44-3 20-4 41-3 27-6 i 17-4 16-7 16-4 6-94 60 53-1 24-5 49-6 33-1 i 20-9 20-1 19-7 8-33 6. SILK. In the case of silk the fineness of the thread is deter- mined in an opposite manner to that practised with other fibres. A sample hank of definite length is taken and weighed with weights of a special kind, the weight of the silk being known as the " titre ". The higher the titre, or in other words the greater the weight of the silk, the coarser is the thread, in direct contrast to other yarns, where the fineness increases as the yarn number rises. 70 YARNS AND TEXTILE FABRICS. The sample hank measures 9600 aunes = 11,400 m. (12,467*4 yds.), the unit of weight being the denier =].'%& grams (0'0464 oz.). However, the full hank is not weighed, but only ^jth part thereof is taken as a standard cut or lea, of 400 aunes = 476 m. (520*57 yds.), and weighed with grani\\Q ^j-th part of a denier or 0'053115 gram the number of gran per cut being the same as of deniers per hank. The single cocoon thread weighs 2 to 2J deniers ; in other silks the " denier" or fineness of the silk varies between 11 and 90, i.e., a hank weighs 11 to 90 deniers. The finest organzine silk varies between 11/12 and 22/26 ; medium from 24/28 to 28/32 ; those between 30/34 and 60/70 ranking as coarse. Fine weft or trame silks range between Nos. 12/14 and 24/28 ; medium from 26/30 to 32/36, those between 36/40 and 70/80 being classed as coarse. The above-named units of weight are fractions of the old Parisian lb., the old Turin lb., or the weight of the old Mailand gold mark. 1 Paris lb. of 16 oz. of 24 gran = 9216 gran, or 489-5 grams (1-077 lb.), so that the denier = 1275 grams. 1 Turin lb. of 12 oz. = 6912 gran, or 368-8 grams (0-8113 lb.) d. = 1281 ,, 1 Mailand gold mark of 8 oz. = 4608 gran, or 235 grams (0-517 lb.) ; d. = - - 1-224 Average d. = 1-26 grams- Average a. = J.-ZD grams- Adopting this average value as a basis, the lengths of silk per kilo, are as follow : 2 d.= 4, 528,000 m. = English cotton yarn No. 2673 4 d. = 2,264, 000 , = 1336 7<2. =1,294,000 lQd.= 906,000 16d.= 566,000 24 d. = 377,000 40 d. = 226,000 60 d. 151,000 80 d. = 113,000 764 535 334 134 89 67 DETEEMINING THE YAEN NUMBEE. 71 Frequently the cut is made up to the round figures 480 in. instead of 476 m., in which case the 9600 aunes = 11,520 m. (12,598'62 yds.). In Italy cuts of 450 m. (492*14 yds.) are made and weighed with 0'05 gram ; twenty-four of such cuts measure 10,800 m. (11,811 yds.). In France the new titre is employed, the cut being made 500 m. (546*81 yds.) in length and the denier weight = 1*333 grams (0*469 oz.). International Reel. The International Yarn Numbering Congress, held at Vienna in 1873, decided to fix the number of silk as the number of grams weighed by a thread 10,000 m. (10,936*3 yds.) in length, 500 m. (546*8 yds.) being the unit of length and 0*005 gram the unit of weight for testing purposes. To determine the correct titre it is necessary to wind several skeins of the standard length and weigh them, the average of the resulting figures being taken. It is always customary to give the limits of variation in weight of the individual skeins in a sample, the numbers being then written like fractions, as above. For the conversion of the new titre into any of the older standards and vice versa, all that is necessary is to multiply, or, conversely, to divide by the subjoined figures : Old Turin titre - 0-8931 Mailand titre - - - 0*9315 French titre - - . 0-8964 Italian (also Swiss) titre - 0-9000 7. CHAPPE SILK. In Switzerland and France chappe silk is reeled in lengths of 500 m. : 1 skein, of 5 cuts, of 100 threads, of 1 m. = 500 m. The number indicates the number of skeins of 500 m. each that go to J kilo. 72 YARNS AND TEXTILE FABRICS. In England chappe silk is reeled like cotton. 1 hank, of 7 cuts, of 80 threads, of 1 yds. each = 840 yds. The number gives the number of hanks going to 1 Ib. Conversion. By multiplying the English number by 1'69 the French, Swiss, or metric number is obtained, the converse being effected by multiplying the latter number by 0'59. Following this necessary explanation of the various systems of numbering yarns in use, we now come to the description of the APPARATUS FOR ASCERTAINING THE No. OF A YARN. (a) Arc Balance. This consists in the main of a pointer FIG. 30. Arc balance. rotating on an axis and moving along a graduated quad- rant, on which it indicates various positions of equilibrium. The yarn to be tested is affixed to the hook shown in the illustration, whereupon the number of the yarn can be read off direct from the indicator. The graduation varies of course with the system of numbering employed, so that we have cotton balances for metric and English systems, wool DETEKMINING THE YAEN NUMBEE. 73 balances for the same systems, and so on. Moreover, various numerating scales can be attached to the same balance for the same material, an arrangement which is very convenient for the comparison of yarns. The balance illustrated consists of an iron frame with an adjusting screw, a brass pointer, and silvered brass scale. A weight is provided for attachment to the pointer when it is desired to ascertain the number of a yarn of ten times the unit length. (5) Micrometric Yarn Balance. For determining the exact number of a yarn from very short lengths, e.g., 4, 20, FIG. 31. Micrometric balance. or 40 yds., or 5, 25, or 80 m., without having to employ a whole reel, the following balance is used. Like the one just described, it is provided with a check weight for test- ing, and also with a measure ( yd. or J m.). It is very useful both in spinning and weaving works, since it enables the number of the yarn in a small piece of finished goods to be quickly and approximately determined both in warp and weft. To this end use is made of the small iron stencil plate, by means of which a small piece (100 square c / m or T V sq. yd.) can be cut out of the piece to be examined, and from 74 YAENS AND TEXTILE FABEICS. this sample a suitable number of threads are taken and washed to free them from dressing. These short threads (50 instead of 5 m., or 40 instead of 4 yds.) are suspended on the balance, and the yarn number is easily read off. (c) Horizontal Precision Balance. With this instrument T V numbers can be accurately read off quickly and without difficulty. The balance being set on a table and a screw FIG. 32. Precision balance. removed, the roller of the small balance beam is put in place resting on the larger beam, and the skein to be weighed is suspended on the hook B, the knob A being turned until the beam moves slightly, and the notch E of the beam coincides with the notch D of the index, where- upon the index shows on the scale the number of the yarn. By attaching a weight on the beam of the balance the DETERMINING THE YARN NUMBER. 75 correct number of a ten-fold length of yarn can be ascertained with the same graduation, and by interchanging weights the instrument can be used for various lengths of yarn. The entire graduation can be checked by the aid of a couple of check weights supplied with the balance. (cT) Yarn Balance with Sliding Weight and Adjustable Scale Plate. This balance can be used for all yarns and weights ; moreover, one is not tied down to any definite length of yarn, FIG. 33. Dietze's yarn balance. but can ascertain the number from short lengths of a few inches as well as from larger ones, which in the case of fine numbers may measure several hundred yards. The yarn is hung upon a hook h, and the sliding weight L moved along the beam W until the latter takes up a position parallel to the balanced lever arm ee. Each figure to which the apex of the sliding weight points on the scale must be divided into the total length of the yarn in millimetres. For instance, with a yarn 2400 mm. long (2'62 yds.) which length may be made 76 YARNS AND TEXTILE FABEICS. up of a number of short threads drawn from any one sample if the weight points to 60 on the scale, the yarn 2400 number will be - =40 (metric system). 60 This method is pursued for all textile stuffs, with the exception of silk, for which the procedure is reversed, the scale number being divided by the length of the thread. For measuring short lengths of thread a 10 cm. rod is DETERMINING THE YARN NUMBER. 77 supplied, on which the yarn may be also wound in parallel layers instead of on a reel, and the skein then transferred to the balance. In this manner the number of any yarn can be very quickly ascertained. (e) Steel Beam Yarn Balance. By this balance also the number of a yarn can be very quickly determined from a definite length of thread (e.g., 10, 25 or 50 ???.), and it is par- ticularly useful for fine spins. The arrangement can be FIG. 35. Sampling reel. seen from the illustration, one end of the steel beam carry- ing a hook for the skein of yarn, whilst the opposite arm is fitted with a sliding weight combined with a scale. SAMPLING KEELS. In order to obtain the exact unit length of yarn for testing, recourse is had to the sampling reel. This instru- ment must necessarily be carefully constructed, and is there- 78 YAENS AND TEXTILE FABRICS. fore made entirely of metal. The arms require to be formed in such a manner that bending or alteration of any kind is out of the question. The threads are laid carefully side by side by means of a self-acting guide, so that the circum- ferential length is maintained unaltered throughout the winding, and, by rendering conspicuous every irregularity, enables the fineness and uniformity of the yarn to be FIG. 36. Sampling reel. accurately supervised. Each reel is provided with a reliable counter and bell indicator to ensure the correct number of turns being wound. In order that the reeled yarn may be easily taken off, one of the arms is made to slide upon itself, so that, when pushed in, the yarn hangs loose ; when the yarn is removed the arm is slid back to its original position and fixed there by a wedge. TESTING THE LENGTH OF YAENS. 79 Classification of sample reels for silk : For legal d. (deniers) : 400 turns x 112-5 cm. circumference = 450 m. For old Mailand^j Turin Lyons K ; 40 " x 119 Cm " " = 476 m ' new j For international d. : 400 x 125 cm. ,, = 500 m. Classification for Floret (chappe) silk : 400 turns x 125 cm. circumference = 500 m. (basis 1000 m. per kilo.). Cotton Yarn : English System. Basis 840 yds. = 1 Ib. 80 turns x 7 spindles X 1| yds. = 840 yds. French System. Basis 100 m. = ^ kilo. International System. 100 m. = 1 kilo. 100 turns x 7 spindles x T4286 m. circumference ) or 100 xlO xl m. } = Worsted and Woollen Yarn : English System. Basis 560 yds. = 1 Ib. 80 turns x 7 spindles X 1 yd. circumference = 560 yds. Old and New French Systems. Basis 714 m. = | kilo. 100 turns x 7 spindles x 102 cm. circumference = 714 m. International System. Basis 1000 m. = 1 kilo. 100 turns x 7 spindles x T4286 m. = 1000 m. 100 v X 10 x 1 m - = 1000 m. Linen Yarn ; Basis 300 yds. = 1 Ib. 120 turns X 1 spindle x 2'5 yds. circumference = 300 yds. IV. TESTING THE LENGTH OF YAENS. Of no small importance in the purchase, sale and work- ing up of yarns is the testing of the length of yarn in hanks as well as in cops and bobbins. To this end the counting 80 YAKNS AND TEXTILE FABRICS. reel, shown in the annexed figure, is employed. It consists of a train of wheels fitted in a box, in the cover of which are situated a pair of dial plates, one for displaying (in yards or metres) the units and the other the hundreds of the length reeled. The indicator can, by undoing a screw, be set back to zero, or at 100 or 1000, so that reversing the reel is un- necessary. For weaving purposes, however, full length can only be reckoned upon in but few yarns, since many are reduced in length by spooling, dyeing, bleaching, etc. In this reduction FIG. 37. Counting reel. the dye, material and twist play a considerable part ; fine and loosely spun yarns suffer more loss than stronger and better twisted ones ; dark dyes, such as brown and blue, cause greater loss than paler colours. When the material is of defective composition and badly spun the reduction in length is considerable. If spun in the raw state and then dyed, the yarn shrinks in length more than if dyed before spinning ; on the other hand, yarn dyed in cops and used for weft loses less than if unwound from the cop, dyed in hanks and then re-spooled for weaving. EXAMINATION OF THE EXTERNAL APPEAEANCE OF YARN. 81 V. EXAMINATION OF THE EXTEENAL APPEAKANCE OF YAKN. For various purposes the different yarns are subjected to an examination with regard to their external appearance. Thus a combed yarn (worsted) is required to be smooth and sleek, whilst the converse qualities are exacted for carded yarn, viz., a woolly surface, showing the curl of the fibre. In the case of cottons it often has to be decided whether the yarn has been previously singed or sized, and with linen yarns whether line or tow yarn is present. The latter is readily distinguished by the unequal knots (from shive resi- due) apparent in the thread, which should not occur in line flax. It has also to be determined whether the flax yarn has been wet or dry spun ; the former being recognised by its glossy appearance, whereas dry spun yarn usually pro- duced in low numbers only is dull and lustreless. In silks, raw, boiled, chappe and waste silk (bourette) yarns have to be differentiated. The yarn is moreover examined for its fineness and regu- larity, for uniformity of thickness or alternating knots and weak places ; for which purpose recourse is had to the instru- ment shown in Fig. 38, the YAEN TESTEK. This consists of an iron frame carrying a guiding screw- spindle and thread guide, the latter being moved uniformly in a horizontal direction by means of a crank on the spindle. The bobbin filled with yarn is placed on the latter, and the thread passed through the upper and lower eyelets of the guide and fastened on to the edge of a board covered with velvet, whereupon, the crank being turned, the spindle is moved horizontally, whilst at the same time the small wheel, on the axis of which the velvet-covered board is mounted, is 6 82 YARNS AND TEXTILE FABRICS. revolved by the connecting belt at an equal rate of speed, so that the yarn is not only wound in parallel, but also in equi- FIG. 38. Yarn tester. FIG. 39. Yarn tester. distant layers on the board. The dark velvet cover of the latter shows up conspicuously any inequalities in the yarn DETEKMINING THE TWIST OF YAEN AND TWIST. 83 The board may be removed by undoing a couple of screws in the metal holders, and replaced by another, so that several samples can be compared. The yarn tester shown in Fig. 39 is arranged for two boards side by side, to take the yarn from two bobbins simultaneously. In this test the following points have to be noted : In woollen yarns of equal number the thickness will vary in different samples on account of differences in the twist, a warp being finer in appearance than the same number and colour of loosely twisted weft ; moreover, a dark yarn will seem to be from a half to a whole number finer than one of white wool. Furthermore, if two yarns of the same colour, but made from dissimilar wool, be held in juxtaposition, a difference in the thickness may be apparent even though they be of the same number and twist. VI. DETEEMINING THE TWIST (TOES, DEALL, DEAHT) OF YAEN AND TWIST. The smoothness of the fibre, i.e., the absence of protruding hairs, is, so far as the nature of the fibre permits, influenced by the twist, increasing concurrently therewith. The " degree of twist " is indicated by the number of spiral turns imparted to the fibre within a given length. The extent of the twist depends on : 1. The fineness of the yarn : the finer the thread the greater number of twists must it receive, i.e., the number of twists is in inverse ratio to the thickness of the yarn. 2. TJie length of the fibres : the longer they are the less will be the number of turns required. 3. The object of the yarn : that for warps is twisted more tightly than if intended for wefts, because it is subject to greater tension and abrasion in the loom, whilst weft yarn 84 YAKNS AND TEXTILE FABRICS. requires to be soft and pliant in order to fill the fabric and give it the necessary closeness. Yarns for doubling are given a slighter twist than those for weaving, and yarns for cloth are made with loose twist so that they may form a felt in the fulling process : and so on. (a) COTTON YARNS. From the subjoined particulars it follows that the number of twists per inch can be found by multiplying the square root of the yarn number by 3 '8 in the case of long staple cotton, or by 4 when short staple cotton is in question, 10 per cent, being deducted in the case of weft yarns. In the metric system of numbering, the number of twists per 100 millimetres of the yarn is found, approximately, by multiplying the square root of the yarn number by 14 for warps, 12 for wefts, 16 to 18 for specially hard twisted water- twist yarns, or 14 to 16 for power-loom warps. The following table gives the number of twists per inch for all cotton yarn numbers. : No. Water Yarn. Warp- Weft. Knit- ting. Hosiery Yarn. No. Water Yarn. Warp. Weft. Knit- ting. Hosiery Yarn. 1 4-00 3-75 3-25 2-75 2-50 32 22-62 21-23 18-40 15-56 14-15 2 5-65 5-30 4-60 3-88 3-53 34 23-32 21-86 18-94 16-03 14-57 3 6-92 6-49 5-62 4-67 4-33 36 24-00 22-50 19-50 16-50 15-00 4 8-00 7-50 6-50 5-50 5-00 38 24-61 23-00 20-02 16-94 15-30 5 8-95 8-38 7-25 6-14 5-60 40 25-29 23-70 20-50 17-40 6 9-80 9-18 7-96 6-74 6-12 42 25-92 24-30 21-06 17-82 8 11-30 10-50 9-18 7-77 7-07 44 26-52 24-86 21-54 18-23 10 12-63 11-84 10-27 8-80 7-90 50 28-28 26-50 23-00 19-40 12 13-85 12-99 11-26 9-52 8-66 60 30-97 29-30 25-16 21-20 14 14-95 14-00 12-16 10-28 9-34 70 ! 33-44 31-35 27-17 22-71 16 16-00 15-00 13-00 11-00 10-00 80 35-76 33-52 29-05 24-58 18 16-97 15-90 13-78 11-66 10-60 90 37-88 35-51 30-77 26-04 20 17-88 16-75 14-52 12-29 11-18 100 40-00 37-50 32-50 27-50 22 18-80 17-62 15-27 12-92 11-75 120 43-80 41-06 35-58 30-11 24 19-60 18-37 15-92 13-48 12-15 150 48-96 45-90 39-78 33-66 26 20-40 19-12 16-57 14-02 12-75 180 53-64 50-28 43-58 36-87 28 21-16 19-84 17-19 14-54 13-22 200 56-02 53-02 45-95 38-88 30 21-88 20-51 17-77 15-04 13-67 DETERMINING THE TWIST OF YARN AND TWIST. 85 The twists can be easily determined by fastening one end of a yarn or twist thread in a vice and the other in a hand vice so that the free length of yarn measures exactly 100 mm. (3'93 in.), and then turning the hand screw, under slight tension, in the contrary direction to the twist of the thread until the latter is completely untwisted, counting the number of turns of the screw. The result will be the number of twists per 100 mm. of yarn (of course the same test can be applied to English standards by taking a yarn measuring a certain number of inches and dividing the result by that number to get the twists per inch). The more delicate forms of apparatus will be described subsequently. Some spun yarns are " doubled," i.e., two or more threads are united by twisting them together, the resulting thread being known as "twist" or "cord". The following kinds are distinguished according to their mode of preparation and uses to which they are put : 1. Two- and three -fold twist for warp and weft. 2. Fine wefts (Nos. 80-130), two -fold for half silk. 3. Dyed and finished twist for half silk and ribbon. 4. Best twist for embroidery. 5. Multiple twist for knitting. 6. Tight and loose twists for glove making. 7. Cords for loom harness. 8. Sewing cord or twist. 9. Fancy twists, knopped, watered, glazed, and fleecy twists for modern stuffs. Twists that are to be soft and pliant must be dry twisted, whereas those required to be dense and smooth must be twisted wet. In order that the threads composing the twist may cling closely together, they are twisted in the opposite direction to that originally employed in spinning the com- ponent yarns, i.e., whilst the spun yarns are twisted in the 86 YAENS AND TEXTILE FABEICS. same manner as a right-screw, the "twists" are turned like a reversed-screw. Twist should exhibit an even turn throughout and form a sightly round and smooth thread. If an unequal tension is employed in the preparation it is easily detected, and such a twist is considered as unequally twisted. Lustred twist is two-fold sewing twist, finished with starch and much in use on account of its strength. The turns given per 25 mm. length (1 in.) are, for : No. 16 - - 17 turns. 20 - - 20 24 - - 22 30 - - 24 , No. 40 - - 28 turns. 60 - 34 80 - . - 40 90 - . --. 42 These twists are from one and a half to three times as tightly twisted as the various knitting cords. (b) LINEN YAENS. On account of the length of the fibre these yarns are twisted less than cottons. So, for example, Nos. 10 to 60 warp have 32 to 68 turns, whilst the corresponding wefts have 28 to 60 turns per 100 mm. (8'937 in.). The number of turns per 100 mm. is found approximately by multiplying the square root of the yarn number by 8 for line, and 8'8 for tow warps, and by 6*8 and 7'6 respectively for warps (or by one- fourth of these figures to get the number of turns per inch). (c) WOOLLEN YAENS. The twist given to woollen yarns depends on the quality of the wool, the fineness of the yarns and the purpose for which they' are intended. A distinction is drawn between warp twist, medio twist and weft twist, the first named having to be sufficiently tight to enable the yarn to stand the tension of weaving, whilst preserving a certain elasticity. However, an excessive degree of twist may spoil a warp yarn DETERMINING THE TWIST OF YARN AND TWIST. 87 for weaving purposes or for warping. Such over-twisting is denoted by a tendency of the yarn to curl when hanging loose in the hank. By rnedio twist is understood a yarn with rather more twist than weft, but employed for the same purpose. Weft yarn has a loose twist, which must, however, be sufficient to enable the yarn to stand unwinding from the bobbin. Warp yarns are generally twisted from left to right, wefts from right to left, and although the latter are some- times twisted in the same direction as warps, the reverse is preferable. In the case of carded yarn the number of turns per 25 mm. (1 in.) is found approximately by multiplying the square root of the yarn number by 2'58 for warps and T29 for wefts. Yarn No. Turns per 25 mm. Yarn No. Turns per 25 mm. mm. Warp- Weft. mm. Warp. Weft. 6 6 3 18 11 5-5 8 7 3-5 20 11-5 5-75 10 8 4 24 12-5 6-25 12 9 4-5 28 13-5 6-75 14 9-5 4-75 32 14-5 7-25 16 10 5 40 16 8 Woollen warps are therefore somewhat more loosely twisted than cottons, the wefts being, however, only twisted about half as much as cotton wefts. If the cloth is not to be fulled the wefts are twisted rather more tightly than otherwise. Shoddies must be more strongly twisted than yarns from natural wool. Worsted yarns are divided according to their employ- ment as warp, medio twist and weft ; the hardness or softness of the thread, resulting partly from the degree of twist and partly from the length and other properties of the 88 YAENS AND TEXTILE FABRICS. wool into soft worsted, middle worsted and hard worsted ; also, according to the extent of cleaning to which they have been subjected, into unwashed (" in oil ") and scoured worsted. The numbering of turns per 25 mm. is found approximately by multiplying the square root of the yarn number by : 2'2 for hard twist merino warp. 1'9 ,, semi-warp (used as soft warp or as weft). 1-6 soft weft. 1'2 ,, hosiery yarn from long wool. The grades of wool employed for spinning the various yarns are denoted by letters. German spinners prepare from the subjoined wools the yarn numbers indicated opposite each. 3A (Electa wool) warp Nos. 60 to 100, weft Nos. 60 to 150 2A (Fine merino) ,, 18 60, 18 75 A (Merino) - ^ B (Purified native I 18 55, 18 60 wool) C (Fine native wool) warp and weft Nos. 18 to 45. In preparing doubled yarns the direction given to the twisting is, as already mentioned, the reverse of that used in spinning the component threads. If this is not done the finished cloth will have a hazy appearance that is some- times intentionally produced for special effects by omitting the reversed twist. The number of turns is varied according to the nature of the material, the fineness of the yarn and the purpose the latter is destined to serve in the fabric. (d) SILK. The reeled raw silk, or grege, is not in a suitable condition for weaving and must be twisted to combine several threads into one. The first twisting (filato) is to the right, and several of these threads, being then re-twisted or doubled DETEEMINING THE TWIST OF YAEN AND TWIST. 89 (torto) by a turn to the left, form "thrown" silk in contradis- tinction to chappe or spun silk. According to the composition and twist of the threads silk is classified into : (1) Organzine (Warp, or Orsoy Silk). From 3 to 8 cocoon threads are lightly twisted together with a right-hand twist, so that there are 60 to 80 turns per centimetre (0'3937 in.), and 2 or 3 such threads are twisted together (left twist) to form double or three-fold organzine. (2) Trame or Weft Silk. This is characterised by a much lower degree of twist ; the individual threads, consisting of 3 to 12 cocoon threads, undergo no preliminary twist, and 2 or 3 of these are united by loose twisting so that the thread is softer and flatter than organzine. (3) Marabout Silk is used for making crape, 2 or 3 threads being united without any preliminary twisting, then dyed without scouring, and strongly twisted. The hard twist and stiffness are characteristic of this silk. (4) " Soie Onde'e" is prepared by doubling a coarse and a fine thread. The material (gauze) made from this silk has a moire (" watered ") appearance. (5) Cordonnet. 4 to 8 twisted threads are combined by a loose left twist, 3 of the threads thus formed being united by a right-handed twist. This silk is used for selvages, braid- ing, crocheting, knitting, etc. (6) Sewing Silk (Cusir) is made from raw silk (3 to 24 cocoon) threads, 2, 4 or 6 of which are united by twisting. (7) Embroidery Silk, also used for brocheing fabrics, consists of a number of simple untwisted threads united by a slight twisting. (8) Poil t or Single, Silk. A raw silk thread formed by twisting 8 to 10 cocoon threads, and employed in making gold and silver tinsel. 90 TARNS AND TEXTILE FABRICS. APPARATUS FOR DETERMINING THE TWIST OF YARN. Twist Tester. The instruments shown in Figs. 40 and 41 are employed for determining the number of twists in a FIG. 40. Twist tester. given length of yarn and the reduction in length it has thereby sustained. They require no further explanation. Real's Twist Tester. The apparatus, made by Heal & Co. of Halifax, consists of a base plate on one side of which is erected a frame supporting two small axes. One of these axes is fitted with a crank and also carries a spur-wheel, engaging in a small spur-wheel on the upper axis, in addi- tion to an endless screw which engages in the teeth of a FIG. 41. Twist tester. graduated indicator plate. The outer end of the upper axis terminates in a catch for holding one end of the yarn thread under examination, whilst the other end runs over two up- rights, the further of which carries a small pulley, and the inner one a small split catch. This latter upright slides for DETEEMINING THE TWIST OF YAKN AND TWIST. 91 a distance of 15 inches along a groove in the base plate, and can be fixed in any desired position by means of a thumb- screw, the adjustment being denoted by graduations on the plate. To test the twist of a yarn the zero on the counter is adjusted to coincide with the pointer. The movable upright is placed in a position corresponding to the length of the sample of yarn, and the latter is fastened in the revolving catch, then passed over the second upright and over the pulley on the first upright, the free end being fastened to a small weight which varies in size according to the elasticity of the yarn, being heavier for stout and lighter for weak yarns. The split catch on the second upright is then FIG. 42. Heal's twist tester. screwed up, the lower axis set in motion by the crank and the yarn untwisted, the degree of twist being recorded by the indicator and read off direct. The indicator is arranged to register both right- and left-handed twists, and as one turn of the crank produces ten revolutions of the yarn the determination is quickly performed. Twist Tester with Expansion Measurer and Turn Counter. This instrument is also applicable to the determination of the twist of doubled yarn, e.g., sewing cotton, sewing silk, etc. After adjusting the counter at zero the thread to be tested is fastened in the two small screw clamps, the one of which is situated to the right of the counter and the other on the left by the elasticitimeter. The latter appliance YARNS AND TEXTILE FABRICS. must be drawn so far out of the collar that the spiral spring of the meter is under proper tension and the indicator screw in position against the zero point on the scale. By turning the crank the doubled thread ^ is untwisted, a needle fixed in 02 "S the guide frame being inserted between the two threads. As the crank revolves the "g needle is drawn between the c3 g threads until they are com- % pletely untwisted. The counter g then indicates the number of .2 turns in the thread, while the O3 meter shows on the left the m elasticity of the thread in milli- | metres. The length of the test thread can be adjusted as 1 desired, by moving the meter | support along the graduated slide (50 cm. in length). It CO "*! is convenient to express the results on the basis of 1 metre ; so, for example, if the sample thread measures 40 cm., the number of turns 140, and the expansion 16 mm., these results come out per metre. 140 X 100 - = 350 turns, and 16 x 100 40 40 cent, reduction in length in twisting. = 40 mm., or 4 per DETEEMINATION OF TENSILE STRENGTH AND ELASTICITY. 93 VII. DETEKMINATION OF TENSILE STKENGTH AND ELASTICITY. Tensile strength and elasticity are two important pro- perties, both of which the spinner and weaver have to keep in mind, since their simultaneous presence is essential to a good thread. Testing by breaking with the hands is un- reliable and defective, and has long been abandoned in favour of suitable mechanical testers, by means of which the spinner is enabled to check the working of his machinery and to decide what to do in case of a change in the raw material he works with. The weaver also has at disposal a reliable means of accurately comparing textile stuffs of different origin in order that he may, from the results ob- tained, appropriately modify the reeling and warp tension. The tensile strength in materials of identical constitution varies inversely with the yarn numbers. So, for instance, if a No. 40 yarn has a breaking strain of 200 grams (7 oz.), then a No. 20 yarn of the same material will have a tensile strength of double that amount = 400 grams (14 oz.), and a No. 1 yarn a strength of forty times that of No. 40, i.e., 8000 grams (17'6 Ibs.). These figures obtained for No. 1 yarns are known as "Quality Numbers," and give when divided by the yarn number the tensile strength in grams (or oz.), and so facilitate comparison. The " Quality Numbers " of cotton yarns have been deter- mined, and average For weak yarns - - - - 4000 grams = 140-8 oz. ,, medium yarns - . ? ~ - 5000 = 176-0 strong yarns - - - - 6000 =211-2 ,, very strong yarns - - - 7000 ,, =246 -4 extra strong yarns (prima) - 8000 ,, =281 -6 To determine the quality of a yarn, from 10 to 20 break- 94 YARNS AND TEXTILE FABRICS. ing strain tests are made with the testing machine described below, and the mean value of the results is multiplied by the yarn number, the product being the quality. By this means a decision can be simultaneously arrived at with respect to the uniformity of the yarn. To this end use is made of the breaking strain figures, and in this case of those falling below the mean, from amongst which a second or "sub-mean" is constructed. The difference between the sub-mean and the mean (which is most suitably expressed in percentages) gives the degree of irregularity of the yarn. For example : A cotton warp yarn, No. 36, gave Breaking strain, No. 1 2 3 4 5 6 7 8 9 10 180 grains. 175 210 195 200 185 355 210 160 190 Total for 10 tests = 1860 grams. The "mean" is therefore = 186 grams. The tests coming out below this mean were : Total for No. 1 = 180 grams. ,,2 = 175 ,,6 = 185 ,,7 = 155 ,,9 = 160 5 tests = 855 grams. 855 The " sub-mean " is therefore = 171 grams, and the difference between mean and sub-mean 15 grams, which, expressed in percentages = = 8 per cent. '.. * ' -LOO DETERMINATION OF TENSILE STRENGTH AND ELASTICITY. 95 The strength of the yarn therefore was 186 grams (6 '54 oz.), and its irregularity 8 per cent. By practical experience it has been determined that when the difference between the mean and sub-mean varies Below 10 per cent, a yarn is considered as very uniform. ,, 15 ,, ,, ,, uniform. Above 15 ,, ,, ,, irregular. The strength of single cotton yarns is given in the subjoined table in grams (= O3527 oz.) : No. Weak. Medium. Strong. Very Strong. No. Weak. Medium. Strong. Very Strong. 4 880 1000 1250 32 125 170 200 250 6 670 920 1080 1340 34 120 160 190 220 8 500 690 810 1000 36 110 150 180 210 10 400 550 650 800 38 105 140 170 200 12 330 460 540 660 40 100 135 160 190 14 285 390 460 570 50 110 130 140 16 250 340 400 500 60 90 110 125 18 220 300 360 440 70 80 90 105 20 200 280 320 400 80 70 80 95 22 180 250 295 360 90 60 70 85 24 170 230 270 330 100 55 65 80 26 150 210 250 310 110 50 60 70 28 140 200 230 290 120 45 55 60 30 130 180 215 260 The strength of flax yarns is easily calculable from the subjoined formula : Let G = strength (grams or oz.), N = yarn number; then, for tow yarns for hand -looms L G = 19,OOQgrams . 2 Q = 21,000grams > ^ the gtrength of ^ 16 yarn = 1187 grams (41-78 oz.) ; or 1312 grams (46-18 oz.). In English four-fold sewing twist : G = 21>885 g rams . In string from fine-hackled flax : double twist : G = 31 316 g rams ; three- fold : G = 32,50Qgrams . 35,780grams . 41,000grams . of gix gmdeg 96 YAENS AND TEXTILE FABKICS. By moderate twisting the strength of the thread is- increased, but if twisted to excess it becomes brittle and loses its elasticity. The elasticity of a yarn is expressed by the increase in length it undergoes when strained to breaking point. This is determined in a simple manner by making one end of a half-metre (19 '68 in.) length of yarn fast, and attaching the other to a drum 5 cm. (2 ins.) in diameter, the axis of which is at a distance of half a metre from the other extremity of the yarn. By means of a crank this drum is revolved until the thread breaks, the arc through which the periphery of the drum has moved, and which is ascertained by the graduated markings on the same, indicating the elasticity of the yarn. The elasticity of cotton yarns should be about : For Nos. 20 to 30 30 40 60 80 120 140 40 60 80 120 140 170 4-5 to 5 per cent. 4 3-8 3-5 3-0 2-5 2-0 4-5 4 3-8 3-5 3-0 2-5 The following particulars of the tensile strength and elasticity of wool fibres are given by Bowman : Kind of Wool. Breaking Strain. Grins. = Oz. Elasticity. Per Cent, of Length. Diameter of Fibres. Inches. Leicester Wool 32-63 1-15 0-284 0-00181 South Down Wool - 5-59 0-20 0-268 0-00099 Australian Merino - 3-25 0-114 0-335 0-00052 Saxon Merino 2-54 0-0894 0-272 0-00034 Mohair - 38-09 1-34 0-299 0-00170 Alpaca - 9-68 0-337 0-242 0-00053 The elasticity of silk amounts to a seventh to a fifth of the length. Eaw silk is more elastic, and withstands strain better than scoured silk, since, in the operation of boiling, DETEEMINATTON OF TENSILE STKENGTH AND ELASTICITY. 97 about 45 per cent, of the elasticity and 30 per cent, of the tensile strength are lost. Wet silk has more elasticity but less tensile strength than dry. On the proposal of Reuleaux the definition of "breaking length," i.e., the length of a thread, at which the thread itself is broken by its own weight, was adopted. The accompanying table has been compiled from the results of experiments : Breaking Length in Kilometres Tensile Strength in Kilo- Breaking Length in Kilo- Tensile Strength in Kilo- (1093-6 yds.). grams per sq. mm. metres. grams per sq. mm. Sheep's Wool 8-30 10-9 Vegetable Silk - 24-5 Cocoanut Fibre 17-8 29-2 Cotton 25-0 37-6 Jute - 20-0 28-7 Hemp 30-0 45-0 China Grass 20-0 Manila Hemp - 31-8 Flax Fibres 24-0 35-2 Raw Silk - 33-0 44-8 APPARATUS FOR TESTING THE BREAKING STRAIN OF YARN. 1. Pocket Tester (Ulmann, Zurich). A spiral spring is enclosed in a wide, round or elongated cylindrical case (Figs. 44, 45). To the end of the spring is attached a hook, on to which the end of the yarn, under examination, is fastened, and the instrument being held or suspended by the ring at the top the yarn is pulled until it breaks. In the watch-shaped tester (Fig. 44) the black pointer will fly back to zero at the instant the yarn breaks, leaving the white pointer to indicate on the scale the tensile strength of the yarn in grams. This white pointer must, of course, be adjusted to zero before commencing the -next test. The tester shown in Fig. 46 consists of a cylindrical case enclosing a spiral spring, the box containing the instrument being convertible into a stand for same. The thread to be 7 98 YARNS AND TEXTILE FABRICS. tested is pressed down on the table with the thumb, fastened on to the hook, and the end drawn out by the other hand until the yarn breaks. The breaking strain is expressed in weight by the position of the indicator on the scale. 2. Breaking Strain Tester for Simple Threads (without the elasticitimeter). The instrument consists of a stand on FIG. 44. Pocket instru- ment for testing the strength of yarn. FIG. 45. Pocket instru- ment for testing the strength of yarn. FIG. 46. Break- ing strain and elasticity tester. which is mounted an arc graduated in front, as a scale, at intervals expressing 10 grams weight, the upper edge of the arc being cut as a toothed rack. The stand also carries a lever, one arm of which terminates in a hook for holding the yarn, whilst the other, forming the pointer, is straight and fitted with a small detent. To apply the test the base screws are adjusted until the instrument is upright ; the yarn is DETEEMINATION OF TENSILE STBENGTH AND ELASTICITY. 99 attached by one end to the hook, and the other end, after being passed over a small roller at the base, is pulled gradu- ally until it breaks, the detent engaging in the teeth of the arc as the pointer moves, and detaining the latter in the position it has assumed when the breaking point is reached, thus enabling the weight indicated to be read off at con- venience. The test should be repeated about ten times in order to obtain the true average breaking strain. FIGS. 47 and 48. Breaking strain tester. 3. Elasticity Tester. A small instrument for this purpose is shown in Fig. 49. This is screwed on to a table, and the thread to be tested is wound round the horizontal roller, one end being held fast whilst the other is pulled until the thread breaks, whereupon the position of the indicator will show the elasticity of the yarn in millimetres. 100 YAENS AND TEXTILE FABRICS. 4. Combined Breaking Strain and Elasticity Tester (Fig. 50). This instrument is fastened on to a table by means of the FIG. 49. Elasticity tester. FIG. 51. Breaking strain tester. FIG. 50. Combined breaking strain and elasticity tester. clamp, the yarn being then twisted around the small upper roller and passed between the roller b and the two small DETERMINATION OF TENSILE STRENGTH AND ELASTICITY. 101 rollers shown in the Fig. ; the lower end passing down to the crank axis, to which it is attached by a clamping screw. The crank is turned until the thread breaks, whereupon the indicator a will show the breaking strain in grams, and the scale will record the elasticity of the yarn in millimetres. Both the indicators a and b should be set back to zero before commencing a test. The tester shown in Fig. 51 is intended for the same pur- pose as the others, but can be used for testing 10 or more threads at a time. The apparatus is fixed on a board, and carries a large dial plate on which the scale is marked, a FIG. 52. Piat and Pierrel's breaking strain tester. weight being used, in place of a spring, for determining the breaking strain. The scale is usually graduated up to 10 kilos. (22 Ibs.). If doubled yarns are tested the result must be divided by the number of component threads, in order to obtain the figures denoting the individual strength. In the case of doubled threads, the strength is increased by the operation of doubling. 5. Piat and Pierrel's (St. Maurice) Breaking Strain Tester. As can be seen from Fig. 52, the instrument consists of two parts, that on the left being the indicator of the tension 102 YAKNS AND TEXTILE FABRICS. produced by the right-hand portion of the apparatus. The thread is stretched by turning the crank, whereupon the lever inclines and the pointer indicates on the graduated quadrant the tension on the thread at the moment of break- ing, a detent restraining the lever in its actual position at the time ; this gives the breaking strain. The elasticity stands in direct relation to the stretch of the thread, and is measured by the distance travelled by the detent along the toothed quadrant. Of course, the test must be performed on a number of threads. The test weight is made heavier or lighter ac- cording to the strength of the yarn, and the figures obtained for the breaking tension must in each case be multiplied by the weight employed. 6. Sehopper's Yarn Tester. The apparatus described below was designed in response to an invitation by the Eoyal Ex- perimental Institute at Charlottenburg. The arrangement can be seen from Fig. 53, and the test is applied as follows : After the loaded lever G has been adjusted to point to zero, the upper tension clamp J is held back by the catch provided for that purpose, and the lower clamp M raised to its highest position, by turning the hand wheel, and fixed in place by means of the screw X, situated below the nose lever 0. By pushing the tension rod case up as far as pos- sible, the expansion lever is adjusted at zero, and the thread is then fixed in position, an operation more easy of perfor- mance with this vertical apparatus than with horizontal instruments. The upper clamp is then released from its catch and the loaded lever also set at liberty ; and the clicket d being lowered, the apparatus is set in work by turning the hand wheel B. After two or three turns of the wheel, and without stopping, the lower clamp is released by undoing the screw X, so that when the thread breaks this may fall and so release the expansion lever. When breakage DETERMINATION OF TENSILE STRENGTH AND ELASTICITY. 103 occurs both the levers remain in their actual position at the moment whether the hand wheel is stopped or not and so allow the breaking weight and the expansion to be read off with accuracy. If, in addition to the breaking strain, the breaking length FIG. 53. Schopper's breaking strain tester. has to be determined, both ends of the broken thread are cut off short at the clamps and weighed together. The calculation of the breaking length is performed according to the well-known formula : R (breaking length) = L x B 104 YABNS AND TEXTILE FABRICS. wherein L = length of the broken thread ; G = weight of the same ; and B the weight representing the breaking strain. In setting up this instrument care must be taken that FIG. 55. Clamps. FIG. 54. Breaking strain and elasticity tester. the indicator of the weight lever is adjusted to zero and that the air bubble in the level at the foot of the stand is exactly in the centre. DETERMINATION OF TENSILE STRENGTH AND ELASTICITY. 105 7. Breaking Strain Tester with Elasticity Tester (Fig. 54). This apparatus is also arranged to work by dead weight instead of by a spring, and is used for testing whole and half cuts of string, cord, etc., the test being very quickly per- formed. The skein under examination is attached to sufficiently strong hooks both above and below, and the crank with attached gearing set in motion until breakage occurs, the strain being indicated on the dial plate, where the expansion is also recorded in millimetres. To ascertain the true elasticity of the thread, the figure recorded on the scale attached to the lower hook is deducted from that shown on the dial. The instrument is mounted on a stout oaken board, and all the parts are constructed of steel and brass. A large quantity of yarn is required for the test, but the results are characterised by greater accuracy. In attaching the yarn to the hooks the turns should lie side by side so that they may slide freely when stretched. Instead of hooks, clamps (Fig. 55) may be fitted to the machine, which is thus made available for testing cloth as well as yarn. The driving wheel may be arranged to work by hand or power. 8. Continuous Tester for Determining the Elasticity and Strength of Yarn. This apparatus (invented by Holzach and made by Wenner of Zurich), which is of great service to the spinner, indicates automatically and simultaneously both the strength and elasticity of the yarn which is being passed through it. Being driven by belting, a considerable length of yarn (some 15 metres per minute) can be tested in a short time. The thread runs from the bobbin through the guide L on to the pair of conical rollers A, and being held fast by the upper pressure roller (covered with rubber or leather), passes over the pulley of the spring balance S and is drawn by the pressure roller of the pair of cylinders B (worked 106 YAKNS AND TEXTILE FABEICS. by the intermediate gear P speed, 120 turns) and wound on a plush roller. The guide L can be slid along a scale indicating the percentage of expansion sustained at any moment by the thread. The two pairs of rollers are of different diameter, but are driven at an equal number of turns. The farther the guide L is pushed towards the FIG. 56. Holzach's continuous tester. smaller end of the cone, the greater is the difference traversed by the thread over B as compared with A, the maximum of difference giving the expansion of the thread at the time of breaking. The breaking strain is indicated by the balance S, and the machine is thrown automatically out of gear when the thread gives way. ESTIMATING THE PERCENTAGE OF FAT IN YARN. 107 VIII. ESTIMATING THE PEECENTAGE OF FAT IN YAKN. This determination has to be made in the case of worsted, carded wool, and artificial wool yarns, and can be performed in a Soxhlet extractor by means of petroleum spirit, the simplest method of procedure being, however, as follows : 5 grams of yarn are steeped with 100 c.c. of petroleum spirit in a flask, well shaken up and left to stand for a day, whereupon 5 c.c. are syphoned off and the spirit removed by evaporation in a tared basin over the water bath. The employment of petroleum spirit is preferable to using other solvents such as water-free ether or carbon bisulphide. When the Soxhlet extractor is used, 2 to 5 grams of the material are placed in the widened tube, which is fixed on to a small flask (weighed when dry), the latter being half full (about 50 to 70 c.c.) of ether, and the apparatus is sur- mounted by an inverted condenser in which the ascending ethereal vapour is condensed and continuously falls back into the extractor. After the apparatus and its contents have been heated for some time over the water bath, all the oil and fat in the substance will have passed into solution in the ether, the flask being then removed and the ether distilled, the residual fat being dried for a half to three-quarters of an hour at a moderate temperature, and weighed when cold. The . increased weight of the flask gives the amount of oil and fat present in the sample. 108 YARNS AND TEXTILE FABRICS. IX. DETEKMINATION OF MOISTURE. CONDITIONING THE YARN. All fibres, whether of animal or vegetable origin, are endowed with the property of hygroscopicity, i.e., power of absorbing water from the air, and undergo alterations in weight and volume corresponding to the amount of moisture so taken up. In damp air they expand and become heavier, and in dry air contract and lose weight, the cause of this phenomenon being due to the variable temperature of the atmosphere. According to the origin of the fibre the quan- tity of moisture absorbed and retained is larger or smaller. By reason of this peculiarity insurmountable difficulties would attend commercial dealings in textile fibres, especially the more expensive products of silk, were there no means of determining and taking into account the percentage of moisture they contain. At the request of the parties interested, the maximal admissible percentages of moisture for the various fibres, and the normal amounts present therein in the air-dry con- dition, were experimentally ascertained some fifty years ago. These investigations led to the installation of testing institu- tions, the so-called "conditioning" establishments, of which there are now some thirty-two in existence for the examina- tion of silk; e.g., Lyons, Paris, Mailand, Marseilles, Florence, Turin, Vienna, Zurich, Basle, Crefeld, Elberfeld. For a number of years attempts have been made in Germany to have 'the condition of wool and woollen yarns officially deter- mined under legislative control. So far as the vegetable fibres are concerned, it is but seldom that any account is taken in commerce of their con- tent of moisture, although, as is shown in the subjoined tables, the amount of water fixed by the various fibres is not unimportant. DETERMINATION OF MOISTURE. 109 TABLE OF WATER CONTENT OF DIFFERENT FIBRES, IN AN AIR-DRY CONDITION, AND AFTER EXPOSURE FOR SOME TIME IN AN ATMOSPHERE SATURATED WITH MOISTURE. Water content Maximum Water content Maximum Fibre. air-dry condition. Per cent. per centage absorbed. Fibre. in air-dry condition. percentage absorbed. Cotton - - - 6-66 20-99 Manila - - 12-50 40-00 Flax (Belgian) 5-70 13-90 Jute - - - 6-00 23-30 4-20 1 24-00 2 Wool - - - 8-12 30-40 Nettle - - - 6-52 18-15 Silk - - - 10-11 30 The International Congress for the establishment of a uniform system of numbering yarn, held at Turin, agreed upon certain admissible normal percentages of moisture cor- responding to the peculiarities of the various fibres. These quantities are known as the " reprise," i.e., the amount of moisture present in the fibre under ordinary atmospheric conditions, or the amount reabsorbed by the fibre on cooling in the air after having been subjected to prolonged drying in hot air. Increase compared with the dry weight per cent. Percentage of moisture in total weight. Cotton yarn, incl. " imitation " yarn Silk thread -- - 4 10 12 7-83 9-09 10-71 Hemp yarn Tow yarn ------ Jute yarn - Jute yarn (according to Pfuhl) - Carded woollen yarn Worsted - - - - ' - Yarns from wool and silk - - : '; , Yarns from wool and cotton Shoddy yarns 12 12J 13f 14 17 18* 16 10 13 10-71 11-11 12-09 12-28 14-53 15-43 i, a Figures given by the Trautenau Experimental Station for the cultiva- tion of flax. 110 YABNS AND TEXTILE FABKICS. CONDITIONING SILK. After the bale of silk has been weighed, some 18 to 30 skeins of a total weight of about 1J kilos. (3*3 Ibs.) are taken, some from the centre and others from near the outside, and divided into three equal samples, which are accurately FIG. 57. Conditioning apparatus. FIG. 58. Sectional view. weighed. Two of the samples are then placed in the con- ditioning apparatus described and illustrated above (Figs. 57, 58), and are dried for several hours at a temperature of 110 C. The weight is taken at intervals of twenty minutes, and as soon as two weighings differ by not more than | per cent, the weight is calculated to that of the entire bale, with the addition of the legally permissible limit of moisture, DETERMINATION OF MOISTURE. Ill viz., 11 per cent. The third sample is used in the event of any difference resulting. The conditioning apparatus invented by Talabot of Lyons in 1841, and improved by Persoz and Rogeat, is constructed as follows : A constant temperature of 110 C. is maintained in the apparatus by means of two currents of air, one merely luke- warm and the other heated to over 110 C., supplied from a heating stove in the cellar of the building. The hotter current enters through the tube A into the chamber J3, where it divides and passes through thirty-two perpendicular tubes / /, and emerges thence into the actual drying chamber I, in which the silk skeins to be tested are suspended freely from hooks attached to one arm of the balance forming part of the apparatus. The cool y dry air current enters the apparatus through the annular passage surrounding the tube A, plays round the tubes I I, and enters the chamber through an opening, r, in the cover. The two currents can be restricted, increased, or shut off altogether, by suitably adjusting the valve v and the valve controlling the aperture r, without it being necessary to open the apparatus ; and the production of an atmospheric mixture with a constant temperature of 110 C., indicated by the thermometer inserted in the appar- atus, is thereby facilitated. This current of air surrounds the silk, absorbs its moisture, and, laden with the latter, passes out of the chamber into the chimney shaft via the flues E E. In this manner the silk is dried rapidly, the absolute dry weight being obtained in a half to three-quarters of an hour. The air is shut off, by closing the valves, whilst the weighings are in progress. CONDITIONING LOOSE WOOL. The process will be explained on the basis of a 2000 kilos. (4408 Ibs.) parcel of wool sent to be conditioned. The bales 112 YAENS AND TEXTILE FABRICS. are weighed directly on reception, and as accurately as pos- sible, and samples are at once taken from various parts of the different bales. When the bales weigh 120 to 150 kilos. (264 to 330 Ibs.), the samples taken from each must be not less than 1 to 1 J kilos. (2*2 to 3*3 Ibs.) in the aggregate ; and a conditioning test must be performed on each 400 kilos. (880 Ibs.) of wool. The different samples are united, and from the whole are drawn three test samples of 500 grams (1*1 Ibs.), of which two are placed in the apparatus. If, after a short time, the loss in the two samples agrees or differs by barely | per cent., the test is at an end, but if the difference is greater the third sample is tested, and the mean of the results is taken and expressed in percentage. In a 2000 kilos, parcel from ten-to fifteen samples are thus taken, the average percentage loss in which forms a basis of calculation for the entire parcel. If the latter consist of thirteen bales, and a 1| kilos. (3*3 Ibs.) sample be drawn from each, then we have 19J kilos. (42*9 Ibs.) of sample, which may be assumed to be representative of the bulk. From this are taken fifteen samples of 1500 grams = 7500 grams (16 J Ibs.), which, when conditioned, yield a dry weight of say = 6300 grams (13*86 Ibs.), corresponding to an average loss of = 1200 grams (2 '64 Ibs.), or 16 per cent., so that the dry weight in 100 Ibs. of the wool would be 84 Ibs. of actual wool. Now, since the permissible limit of moisture in wool is 17 per cent., there must be added to the 84 per cent, of wool 14*28 per cent, as permissible moisture, which gives the normal weight = 98*28 per cent., and the inadmissible water = 1*72 per cent. Therefore, instead of 2000 kilos. (4400 Ibs.), the weight of the parcel must be reckoned as 2000 - 200 1 ^ 1 ' 72 = 1965-60 kilos. 4324-32 Ibs.). DETERMINATION OF MOISTURE. CONDITIONING WORSTED. 113 The process is identical with the foregoing, but a few preliminaries have to be gone through. When the yarn is on bobbins or conets, it must, after the gross weight has been ascertained, be reeled in hanks of 1000 metres (1093*6 yds.), and the tare deducted. If the yarn contains any matters that volatilise during the drying, it is first washed and freed from fat, and then transferred to the conditioning apparatus. APPARATUS. The Ko/t/ Conditioning Apparatus for wool consists of a delicate balance (constructed for a maximum load of 1 kilo. FIG. 59. Kohl's wool conditioning apparatus. (2'2 Ibs.), and capable of indicating down to 1 centigram) ; a strong copper drying vessel fitted with a thermometer ; an 8 114 YARNS AND TEXTILE FABRICS. iron case ; a drying rack for cops ; another for sliver ; and a pair of gas burners or petroleum stoves. The drying frame suspended from the balance is filled with a number of cops or sliver, the weight of which is accurately determined at the outset, and again after one and a half to two hours' drying, a third weighing being made FIG. 60. Heal's conditioning oven. after the lapse of a further half-hour. If no loss of weight occurs between the second and third weighings the final weight, with the addition of the permissible percentage of moisture, is calculated to the total amount of the wool. Heat's Yarn Testing Oven (Fig. 86) consists of a cylindrical vessel fitted with a conical movable cover, and containing DETERMINATION OF MOISTURE. 115 an inner vessel of slightly smaller diameter, the space be- tween them being closed at the top but open below. At the bottom of the inner vessel there is a plate which is exposed to the flame of a Bunsen ring-burner, the heated gases from FIG. 61. Ulmann's conditioning apparatus. which surround the inner vessel, the products of combustion escaping through the flue shown at the right-hand side of the apparatus. The cops or raw material to be tested are 116 YAKNS AND TEXTILE FABRICS. laid in a circular wire basket made in two parts in order to ensure an equal distribution of heat through the cops. The material is of course weighed before being placed in the basket. The temperature of the apparatus is registered by a thermometer inserted through the lid. Conditioning Apparatus with Arc Balance (Ulmann, Zurich). This useful apparatus is shown in the annexed figure (Fig. 61). The method of manipulation is as follows : The FIG. 62. Conditioning apparatus with sliding weight. rod T supports a basket inside the apparatus, in which 20 grams (0'7 oz.) of the sample to be tested are laid, care being taken to ^prevent contact with the sides of the ap- paratus. The lid M is then closed, and the weights E l are moved along the threaded arm until the pointer is opposite zero on the scale. The spirit or gas lamp E being then lighted, heat is applied until the thermometer J registers DETERMINATION OF MOISTUEE. 117 110 to 120 C., whereupon the internal valve, which is left open at the commencement of the test, is more or less closed by turning the handle H, in order to regulate the admission of hot air and maintain the temperature at the requisite degree. The moisture will, as a rule, all be expelled in about twenty to thirty minutes, the lamp being then extinguished, and the final position of the pointer, which will have risen, indicates, on the scale which is graduated in centigrams the amount of moisture in the sample examined. The oven, which is constructed in two sizes, for conditioning 20 and 100 grams (0'7 and 3*5 oz.) respectively, is of the following dimensions : Diameter, 23 or 25 cm. (9J or 10 in.) ; height, 48 or 68 cm. (19 or 27 in.). The Findeisen (Chemnitz) Conditioning Apparatus (Fig. 62) consists of an oven, a copper vessel warmed by a gas or spirit lamp, and a delicate sliding-weight balance, the pan of which is placed inside the oven. When the sample is placed in the pan the apparatus is heated to 110 C to 120 C. for some time, the dry weight of the substance being ascer- tained by counterpoising the balance by sliding the weight along the beam. TESTING MANUFACTUEEI) FABKICS. "FABRIC" is the name given to any material prepared by the regular interweaving of threads or thread-like bodies by the aid of mechanical appliances. This general classification is subdivided into " weavings " or woven material, composed of threads interwoven at right angles, and worked goods, wherein the threads are combined in serpentine fashion or so twisted as to form a mesh. In this latter category must be included machine lace, tulle, bobbinet, and such like materials, in addition to those produced in hosiery looms. Woven materials are constructed of longitudinal or warp threads (kette, zettel, aufzug, schweif ; organsin ; chaine), and transverse or weft threads (schuss, einschuss, eintrag, ein- schlag ; trame), in such a manner that the latter pass regularly at right angles backwards and forwards through the warp, and therefore must turn back at the edge or selvedge (sahlband, sahlleite ; lisiere) of the material which is frequently made of a different or stronger class of warps in order to improve the appearance and strength of the goods. Owing to the manifold changes of relative position that can be given to the warp and weft threads, a great variety of fabrics can be manufactured. These are classified into the following four groups : 1. PLAIN OR SMOOTH WEAVINGS. The weft thread has only two positions, this being the simplest form of combination possible. TESTING MANUFACTURED FABRICS. 119 (a) Canvus Fabrics, and the like. In these the even warp threads lie above during the first passage of the weft, and the odd threads below, the position being reversed in the second passage. (6) Gauze-like Plain Fabrics. These show the one half of the warp threads, e.g., the even numbers, always above, and the odd ones always under the weft. 2. TWILLED FABRICS (KOPER ; CROISE). The shott (weft) thread always takes up more than two positions ; it may pass over two, three and more warp threads, and produces on the surface of the material diagonal lines, either continuous or interrupted. (a) True Twill (Croise). The lowest form is the 3-shaft twill, in which the weft passes under two and over one of the warp threads alternately. In 5-shaft twills four warps lie above, and one warp under, the weft. If the warps above and below the weft are equal in number, the product is known as double or Batavia twill. (6) Atlas. The warp lies very free, whereby the well- known, smooth surface of the atlas twill which is highly lustrous in silk goods is produced. The true atlas is 8- shaft, the bastard atlas a 5-shaft fabric ; in the former the weft passes under seven and in the latter under two warps before covering another. 3. FIGURED FABRICS. Figured goods are those in which a design or pattern is reproduced by peculiar manipulations of warp and weft, the latter having always more than two (and generally a large number) of different positions. The portion of the material surrounding the design is known as the " ground/' the pattern itself being called the " figure ". In order to throw 120 YABNS AND TEXTILE FABEICS. up the design the ground may be either plain, twilled, or variously coloured (taffeta ground, gauze ground, etc.). 4. VELVETY FABRICS. On an ordinary plain ground a hairy cover or pile of upstanding or recumbent fibres may be formed. In the case of imitation (Manchester) velvets the pile is formed from the weft, but in true velvet (silk velvet), from an extra warp thread, the so-called pile warp. CLASSIFICATION OF WOVEN GOODS. The largest group is formed by cotton goods, to which various arbitrary designations are given. Among the plain goods are: Cottons (Nos. 20 to 30 yarns), calicoes (Nos. 36 to 42 yarns), chiffon, percale (Nos. 50 to 60 yarns), Scotch batiste, Scotch or Viennese canvas, muslins (Nos. 60 to 80 yarns), Mollinos (strong coarse fabrics from Nos. 14 to 26 yarns), tulle and gauze. Among the twills are : TwilL dimity, English leather, moleskin, molton, twilled nan- keen. Atlas fabrics : Satin. The figured cottons are very numerous : Repps, piques, cotton damask, double cords, etc. Cotton velvet is designated "Manchester". The linen fabrics are divided into : (1) Plain goods, such as linens, creas, stiffened linens, linings, clothings, coatings, trouserings, linen batiste and linen tulle (loosely woven) ; (2) Twilled and figured goods : Tickings, drills, bed drills, trouserings, table and towel drills, linen atlas and linen damask (Jacquard linen). Plain hemp fabrics occur as sailcloth, canvas, hempen cloth, hemp linen, sacking and packing cloths. Jute goods are brought on the market, in ordinary qualities, as packing cloths, sackings and sailcloth, and in finer grades, as carpets, table and bed covers, and curtains. TESTING MANUFACTUKED FABEICS. 121 Woollens are subdivided according to the nature of the raw material, into carded woollens and combed woollens (worsteds). To the first named belong the unfulled or only slightly fulled fabrics, such as flannels, buckskins, ratine, floconne, half-wool llama or union (warp cotton, weft wool), and also the fulled fabrics, the chief representa- tive of which is known as " cloth," by which term is under- stood a plain weaving with its surface converted into a smooth felt-like covering by the processes of fulling, rough- ing, shearing and pressing. This felting is facilitated by using warp threads made with a right-turn, along with left-turn weft yarns. The combed woollens are also a numerous class. To the plain goods belong : Orleans, wool muslin, crape, mohair, repps. To the twills : Merino, Thibet, cashmere, zanella, serges and lastings. The figured goods include : wool- or upholsterer's-damask, vestings, trouserings, shawls, facings and carpets. Velvety fabrics are wool velvet, wool plush, upholstery plush, Brussels carpeting, astrachan and crimeas. Equally varied are the descriptions of silks, due to rapid changes of fashion. The most important plain silk fabric is taffeta, which is used for dress goods or for linings. A closely woven taffeta of very strong threads covered with a kind of regular grain, or ribbed, is known by the names of Gros de Naples, G-ros de Tours and Moire silk. Foulard is used for handkerchiefs, but also for dress stuffs as well. Gauze, crape and barege are also included in this class, the latter being a very light translucent dress stuff. Among the twills are chiefly the following : Croise, serge and atlas, or satin. Figured silks comprise silk damask, broche, gold and silver brocade (interwoven with gold or silver threads). Among the velvety fabrics should be mentioned the true silk velvet which is met with in 122 YAENS AND TEXTILE FABRICS. commerce, both with cut and uncut pile, arid is used as expensive dress material and as costly upholstery and curtain goods, etc. In unions or mixed goods the warp and weft threads are of different materials. In half-silk, for example, the warp is of silk (organzine), and the weft of worsted, mohair, alpaca, or even cotton. Thus poplin contains fine combed wool ; semi-taffeta, cotton ; and atlas twills very low qualities of cottons as wefts. Half-silk velvet is made on a ground of cotton. Barege is a gauzy fabric with a raw silk warp and combed wool weft. The number of semi- woollen fabrics is very considerable. For the most part they consist of wool and cotton, very rarely of wool and silk, the warp in many cloth-like fabrics being of cotton and the weft of carded wool, e.g., flannels (plain or twilled, slightly roughed or cropped and lightly fulled) ; cassinets (twilled or atlas twill, only hot pressed) : unions (half- wool llama), half- wool moleskins and half- wool twills. The half-wool fabrics from combed wool are numerous, among the plain goods being wool muslin (loose, soft tissue),. Orleans (cotton twist warp), repp (mostly cotton or carded wool warp with combed wool weft), mohair. Twilled are : half-wool cashmere (silk warp, merino weft), half-merino (3-shaft twill with cotton warp and combed wool weft, or vice versa), zanella (cotton twist warp, wool weft) ; and the figured and gauzy fabrics comprise half- wool damask (cotton twist warp), and half-wool barege (cotton warp, combed wool weft). In the half-linen (union) fabrics are distinguished : union canvas (made partly from hemp alone and partly from hemp warp and flax weft), tow canvas, half-tow linens, tow weft sheetings (flax warp, tow weft), half-cotton linens or unions (cotton w r arp, flax weft, or vice versa). Among the figured goods are union drills (cotton warp, linen weft) and union damasks. TESTING MANUFACTURED FABRICS. Materials containing threads of other kinds for the pro- duction of special effects are not regarded as mixed goods. THE TESTING OF FABRICS comprises four groups of investigation, the first of which belongs to the domain of mechanical technology and in- cludes : 1. Identification of the mode of weaving ; adjustment of warp and weft ; combination ; external appearance of the individual threads ; yarn number ; doubling twist ; colour, etc. 2. Testing the breaking strain and elasticity by the dyna- mometer. Tearing by hand is an inaccurate test. 3. Determining the "count" of vxirp and weft (porter and pick or shott). 4. Determining the shrinkage or contraction. The second group deals with the identification of the raw material : : 5. Examination of the constituents of the warp and weft threads ; weighing the fabric. The third group is concerned with the substances and alterations introduced into the goods by the processes of dyeing and finishing : 6. Determination of the finish and dressing material. 7. Determination of the waterproof capacity of the fabric. 8. Determination of the absorption of moisture ; artificial weighting. 9. Fastness of the dye under the influence of weather, dirt, dust, washing, perspiration, ironing, etc. Finally, in the fourth group are determined : 10. The length of the piece of cloth, etc. 11. The mordants and dyes employed. 12. The presence and amount of arsenic (if any). 124 YAENS AND TEXTILE FABRICS. I. DETERMINATION OF THE MODE OF WEAVING, DISTINCTION AND COMBINATION OF WAEP AND WEFT THKEADS. In many fabrics the differentiation of warp and weft threads is an easy matter, whereas in others certain indi- cations are necessary. When the sample contains a piece of the selvedge this shows which is the warp, because a selvedge can only be in a longitudinal direction in the stuff. In the case of cloth, buckskin, flannel, etc., and with fabrics gene- rally that have been fulled, raised and cropped, the direction of the hairs composing the pile affords a guide, these being always laid parallel to the warp. If a number of doubled threads are found in a fabric, the others being simple, then the former are the warps. When cotton threads are de- tected as running in one direction and woollen ones in the other, the cotton yarns usually form the warp and the wool the weft. Warp and weft may also be distinguished by the twist of the yarn, the former being the more tightly twisted of the two. Where the members of one set of threads are equidistant and the others at irregular intervals, the former are usually the warps. In stiffened or starched goods, if only the threads running in one direction can be seen, they may be assumed to be the warp, and if one set appears stiffer and straighter, the other being rough, crooked or crumpled, the former may be regarded as composing the warp and the latter the weft. The material also affords a clue, since if one set of the threads is of better and longer material and higher yarn number than the other set, the finer constitutes the warp and the commoner, thicker yarn the weft. Finally, the direction of the twist in the threads is conclusive, so that if one set has a strong right-twist and the other a left-twist, the first may be regarded with certainty as the warp. After the distinction of the warp and weft yarns has been TESTING THE STRENGTH AND ELASTICITY OF A FABEIC. 125 effected in one way or another, it then becomes a question, especially for manufacturers, of determining the combination of the warps and wefts. To this end the sample is examined by the aid of a hand glass or thread counter and a strong style or needle, with which the threads can be counted and moved aside, and the cloth analysed. The position of the threads is called their " combination," and is classified as taffeta, twill, atlas, serge, Batavia, and so forth. The re- sult of the examination is plotted on cartridge paper, the projecting warp threads being indicated by filling up the corresponding squares and leaving those referring to the prominent weft threads blank. In this way the weaving pattern of the sample is obtained, and serves as a guide to the weaver in making the stuff, as well as for the preparation of the pattern cards for the loom. Finally, the individual threads are tested for strength, twist and dye, the methods for which operations have already been detailed. II. TESTING THE STKENGTH AND ELASTICITY OF A FABKIC. The plan, so often adopted, of testing the strength of a cloth by tearing it by the hands is altogether unreliable, and rather leads to self-deception, because tearing frequently requires only a certain skilled knack whereby the best material can be pulled in two, and though an experienced man may be able to distinguish a good cloth from a bad one in this way, yet it is impossible for him to determine slight differences in quality, since after he has exerted his strength over a few tests the capacity to distinguish the actual force required disappears. The sole means of determining the strength of a sample without possibility of error is by means of mechanical dyna- mometers, which moreover possess the advantage of requir- 126 YARNS AND TEXTILE FABRICS-. ing no skilled knowledge in their application, besides expressing the tensile strength of the sample in terms of weight. This latter faculty in particular is valuable to the manufacturer by enabling him to accurately compare his various products with those of his competitors, whereby he receives assistance in improving his fabrics. The tests will facilitate the detection of defects of manufacture which would otherwise be overlooked, and will undoubtedly con- tribute also to strengthening the market, since it is only by means of such tests that one can determine what goods are to be considered as durable and strong. The value of these tests is sufficiently proved by the fact that all Army Clothing Departments and other official departments already make the reception of their supplies of cloth, drills, canvas, etc., dependent on their passing definite tests for strength. Breaking tests also afford the most certain proof to bleachers of cotton and linen goods whether the bleaching process adopted is a rational one, i.e., whether the goods have been weakened or not ; and by the same tests an in- dication can be quickly obtained as to whether body and household linen has been as is so frequently asserted improperly treated in the laundry. In turning to account the results obtained with the testers about to be described, the length of the sample examined, its weight and the degree of force (weight) employed, give the length of the stuff which if suspended would break under its own weight the width being of course considered as equal in both cases. So, for example, if 15 cm. (6 in.) of stuff weigh 1 kilo. (2'2 Ibs.), and break under a strain of 50 kilos. (110 Ibs.), then the tearing length of the stuff will be =7500 metres ( 82 2 * 225 y ds -)- If the strip of cloth is found to have stretched, say 15 TESTING THE STRENGTH AND ELASTICITY OF A FABRIC. 127 mm. (0'6 in.) at breaking point, then the stuff is said to have a " tenacity " of (in this instance) 10 per cent, of the original measurement. In addition to the two definitions, expressed by the terms " specific strength " and " breaking stretch," is associated a third, " specific breaking tension," denoting the product of the tension exerted (weight) and the distance traversed (length) referred to 1 gram (0'035 oz.) of the fabric tested. The subjoined table, compiled by Hoyer, 1 gives, for guidance, the results of several experiments on the count and strength of cloth : Breaking Number of Strain of a Fabric. Weight in Grams per square Threads in 25 mm. (1 in.). Sample 10 cm. (4 in.) wide in kilos. (2-2 Ibs.). metre. 2 Warp. Weft. Warp. Weft. Cotton, unbleached, for shirtings ; 129-135 56 53 90 74 Cotton, blue, for linings - - ; 110-170 60 51 58 50 {Shirting (bleached)- - 225-235 32 28 73 67 Lining (unbleached) - 205-215 Summer trousering 26 22 105 100 (bleached) - - - 240-260 33 30 230 144 Linen twill for trousering (un- bleached) 320-340 30 29 230 200 Orleans, black (cotton warp, wool weft) 63-69 72 62 36 30 Military cloth .... 80-85 37 37 57 52 Coating cloth (shoddy) 30 25 35 34 Sheep's wool cloth{g^_ ; Worsted (black) - 60-64 45-49 50 46 42 60 43 37 55 67 54 100 53 40 92 Silk (ordinary plain) - 20 ' 120 110 1 Dammer's Lexikon der Verfalschungen, p. 333. 2 The weight per sq. yd. in oz. is obtained by dividing the weight per sq. metre in grams by 1-893 x 31 = 33-88, e.g., 130 grams -f 33-88 = 3-8 oz. per sq. 128 YARNS AND TEXTILE FABRICS. BREAKING STRAIN TESTERS (DYNAMOMETERS). Of the various testing machines manufactured, those described below are given as having proved themselves useful and made their way. (a) Rehse's Tester is a pocket instrument which can be recommended when rapid and, at the same time, accurate testing is in question. The stuff is stretched, by means of a pressure screw, between a concave disc and a tube, in such a manner that the entire surface of the tube is covered by the cloth. The sample is pressed upon by a die, driven by a spiral spring, until the stuff, which is forced into the hollow of the concave disc, is torn. The force exerted by the spring is produced by moving a sliding case or drum, the progress of which indicates on a scale the breaking tension and elasticity of the sample under examination. (&) Leuner's (Dresden) Tester. This apparatus registers the elasticity and strain automatically on a strip of paper. The sample is held by a pair of clamps, which are then attached on the one hand to a fixed hook E (Fig. 63), and on the other to the balance, by suitable studs. It is necessary that the initial distance between the two clamps should always be constant, and that whether in consequence of improper adjustment or defective connection with the rest of the apparatus they should not exert a distorting force on the sample. To this end an even tension longitudinal to the threads is essential, and this is ensured by the arrangement of the apparatus. The indicator recording the tension and elasticity consists of a pencil C and a cylinder B, the latter being mounted loose on the draught rod connecting the spring with the clamp, and receiving a rotary motion by means of cone wheel gearing, which motion corresponds to the movement of the clamp at A, i.e., to the total stretch of the cloth. For indicating the amount of extension due to TESTING THE STRENGTH AND ELASTICITY OF A FABRIC. 129 the action of the draught screw at the further end of the spring, in contradistinction to that attributable to the elas- ticity of the cloth, the pencil G moves vertically along the cylinder. for that distance, the compounding of these two movements resulting in a curve, the ordinates of which denote the tension and the abscisse the elasticity. By placing the spiral screw in its normal position with regard to the cylinder, the former are described by the pencil, and the latter result from the rotary movement of the cylinder. For convenience in reading the diagram a glass measur- ing plate engraved on the under side is employed. The FIG. 63. Leuner's cloth tester. divisions marked on the plate show the elasticity in per- centages direct and the tension in units of weight (grams), a method which dispenses with the necessity for drawing the ordinates. The perpendicular, graduated in weight units, is applied to the outermost point of the curve, and, the line corresponding to the abscisse being applied to the starting point, the result is read off. When the breaking point is reached the sudden recoil of the spring is prevented by means of a couple of detents. If the tension of the spring is not great it may be released, after disengaging the detents, by controlling the reverse movement of the cylinder B by the hand; otherwise the 130 YAENS AND TEXTILE FABEICS. detents are left in position, and the spring is restored to its normal tension by means of the hand wheel and screw. (c) Breaking Strain and Elasticity Tester. The sample is evenly fastened between the cheeks (7 1 and C 2 (Fig. 64), the exact distance between them which should be, say, for example, 400 mm. (16 in.) being ascertained at the outset FIG. 64. Breaking strain and elasticity tester. by reference to the graduations on the guide rod E. The cloth is then strained by turning the handle F until it begins to tear, the tension being registered on the dial plate in units of weight (e.g., kilos.). The detents G prevent the pointer from receding, and the elasticity is ascertained by the difference between the initial and final length of the TESTING THE STBENGTH AND ELASTICITY OF A FABEIC. 131 sample as measured on the guide rod E, e.g., initial length 400, final 430 mm. = elasticity 30 mm. FIG. 65. Tarnagrocki's cloth tester. To re-adjust the spring balance to zero, the wheel Fis re- versed until the cheeks C 1 C 2 can be connected by the piece 132 YAENS AND TEXTILE FABRICS. H, the spring being then drawn on slightly to loosen the detent Gr, and afterwards allowed to recoil by continuing to reverse the wheel F. (d) Breaking Strain Tester (by Tarnagrocki of Essen). This- apparatus, which has lately been adopted by the German Official Clothing Department, is made entirely of metal, and consists of an instrument for measuring the tensile strength of cloth, an arrangement for measuring the elasticity, and an arrangement for absorbing the vibration of the spring. The tension applied at any moment is automatically indicated by a pointer, and can be read off at any time. The vertical form of the apparatus enables the accuracy of the scale to be checked by direct loading with weights. When the sample is fixed in position the wedges must be pressed slightly in order to keep the cloth secure and safe. The tension is pro- duced by turning a hand wheel, the motion of which is communicated by screw gearing to the spindle contained in the pillar S t which spindle depresses the draught rod T connected with the lower clamp. By disconnecting the screw gearing and connecting the cone wheels K and K', as is shown in Fig. 65, the lower clamp can be quickly re- adjusted to its original, or any other desired, position, when the sample has been broken. For convenience of reading, the dial plate is placed on a level with the eye, and the maxi- mum movement of the pointer is recorded by a supplemen- tary hand. In setting up the machine care must be taken to have it vertical and fixed on a firm foundation. The method of applying the test is as follows : When the sample strip of cloth has been inserted sideways between the wedges of the stretcher m a slight pull on them is sufficient to fix it securely in place. Tension is then applied by turning the hand wheel, and the pendulum P leaves its vertical situation to take up an inclined position until break- ing is effected, its fall at that instant being prevented by TESTING THE STRENGTH AND ELASTICITY OF A FABRIC. 133 detents dropping into a toothed rod in the lower part of the apparatus. The detents are released on lifting the pendulum by the handle H and giving a slight pull on the cord, and it can then be lowered to the perpendicular. In order to ascertain the elasticity of the sample, a meter FIG. 66. Tarnagrocki's cloth tester. for this purpose is affixed to the upper stretcher head m and rests on a coiled spring, its fine needle points i i being pressed into the sample, which should be 30 or 36 cm. (12 or 14*4 in.) long and 5 cm. (2 in.) wide. The lighter machine of the same maker (Fig. 66) varies slightly from the foregoing, as will be apparent from the 134 YAENS AND TEXTILE FABKICS. illustration. The tension, produced by turning the hand wheel r, is transmitted by the gearing k to the vertical spindle, and thence to the test strip, which latter may in this machine be reduced to 18 cm. (7| in.) in length by 2'5 cm. (1 in.) in width. In an older model the test sample is fixed horizontally between two clamps. The tension is produced by the spoke wheel A, whereby the counterpoise (j is correspondingly moved, as are also the pointer m and the friction pointer n FIG. 67. Horizontal cloth tester. on the scale. Directly the cloth breaks, the counterpoise is restrained so that the breaking strain can be read off on the scale. The counterpoise can then be lowered by releasing the detents by a pull on the cord /, and by the winding arrangement e. The foregoing horizontal machine serves for testing all kinds of driving belts, girthings, strong fabrics, thin ropes, etc. The test sample requires to be from 25 to 50 cm. (10 to. 20 in.) in length and 5 cm. (2 in.) in width. TESTING THE STRENGTH AND ELASTICITY OF A FABRIC. 135 In the official instructions issued to the German Army Clothing Department * the testing machine first mentioned is described in detail as follows : 1. THE DYNAMOMETER. The visible parts of the dynamometer are : (a) A case, of horse-shoe form, constituting the front of the instrument, and covered with an engraved dial plate of brass ; (b) A cast-iron frame- ; (c) Two rods, each fitted with a clamp and hook inside the frame the first being attached to the measuring spring, referred to below, and movable only as far as this spring permits, whilst the other rod can be moved up and down freely ; (d) A large screw fitting on the under side of the frame and worked from the front of the instrument by a hand crank, the female screw being contained in the lower part of the second rod. The most important part of the apparatus, however, is : (e) An elliptical spring, consisting of two blades, and con- nected to a pointer. The function of the horse-shoe case is mainly to hold fast one of the points of the spring ; that of the frame to keep the clamp rods in position ; that of the clamps to hold the sample of cloth to be tested ; that of the large screw to apply tension to the object of the test until breakage is produced ; and that of the spring to measure such tension. The amount of force exerted is indicated by a pointer mounted on the axis of a cog wheel below the dial plate and moved forward from zero by the draught exerted by a hook fixed on the clamp rod, and actuating a rack which engages in the small cog wheel. 1 Dienstanweisung filr die Corps-Bekleidungsamter, p. 105. 136 YARNS AND TEXTILE FABRICS. The effect of the motion imparted by the larger screw is to draw the second clamp away from the first, thereby stretching the test sample and drawing on the upper clamp, tightening the spring and moving the pointer. When the cloth commences to tear, the test is finished, and the pointer retains the position it held at the moment of breaking, its steadiness being explained by the fact that as the spring recoils the clamp hook is released from the rack. The maximum position attained by the pointer is expressed in units of weight (kilos.) an indication of the force necessary to overcome the tension of the sample, i.e., of the breaking strain of the material tested. 2. APPARATUS FOR MEASURING ELASTICITY. As the stretching of the material is a necessary accom- paniment of the breaking strain test, all that is necessary for the determination of the elasticity is an arrangement for recording it. This consists of a scale, graduated in millimetres, affixed to the cast-iron frame, to which it is screwed loosely, and, being notched, is pushed forward by a stud projecting from the first clamp, with which it is always on a level, the pointer being formed by a small bent rod on the second clamp. 3. APPLIANCE FOR ABSORBING OSCILLATIONS OF THE SPRING. The following parts belong to the instrument, but are not necessary to the performance of the test : (a) A quadrangle brass frame about the centre of the springs ; (b) A partly toothed brass rod under the horse-shoe case ; with (c) A projecting arm or angle piece at the side of the case ; TESTING THE STRENGTH AND ELASTICITY OF A FABRIC. 137 (d) A loose rod which, passing through the case and the brass frame, is pressed by the aforesaid arm against the spring ; (e) A spiral spring along the toothed rod to which it is -attached by one end, the other being held by a stay thereon ; and, lastly, (/) A set of toothed gearing, engaging in the rack work on the brass rod, and consisting of a segmental rack with toothed driving gear (axis in the under frame), brake wheel with brake cone, and fly wheel. These parts are only destined to take up and absorb the oscillations of the spring at the moment the test is finished, so as to protect the instrument from injurious jarring. This task is performed in the following manner : During its tension the spring assumes an elongated form whereby the rod accompanying the spring and pressed by the arm acquires a certain play, and as soon as this occurs the extended spiral spring follows its natural tendency to contract, and so puts in motion the wheel gearing by draw- ing the rack engaging with the said gear. After the test object is broken the main spring rises rapidly into its original position, drawing the rod with it, the result being that the arm falls back, the spiral spring is again extended, and the wheel gear reversed. In this retreat the oscillations of the spring are taken up from the rod and carried forward through all the parts to find an outlet in the rapidly revolving fly wheel, and so are rendered harmless towards the apparatus. The following instructions concerning the handling and use of the dynamometer are also given : Handling. The dynamometer should be handled with care, and must be kept in a dry place, besides being cleaned and oiled sufficiently to ensure its preservation and work- ing easily when put into use. 138 YARNS AND TEXTILE FABRICS. The best lubricant for the large screw, as well as the pointer and wheel gear, is neat's foot oil, whilst rape oil is better for preserving the spring. A small hole for oiling the screw is bored through the front of the cast-iron frame. Other precautions necessary for the preservation of the machine will be apparent from the subjoined observations : If the dynamometer is subjected to a heavy jar from a blow or shock, then the spring, dial plate, or pointer may become loosened or shifted even though such be not out- wardly apparent and therefore inaccurate. Although the spring, which is constructed to bear a load of 500 kilos. (J ton), is unaffected by high tension in ordinary measurements, it suffers if left for a long time under very high tension. Moreover, it will seldom stand extension at a temperature below freezing-point, and still less a strong tension resulting from the rotation of the fly wheel ; in the former case it breaks easily, and in the latter may be forced out of its bearings. Finally, it is advisable, for the protection of the spring, not to load it above 250 kilos, (or 5 cwt.). Application. The sample to be tested should be of a certain length for determining the elasticity and a definite width for ascertaining the breaking strain of the material, which sample may be taken from any convenient part of the cloth, but must be cut either in the direction of the weft or the warp. One end of the cutting is fixed in the one clamp and the other inserted in the second clamp, the correct distance between the two clamps being adjusted by the hand before the second one is screwed up. This accomplished, the screw is rotated at suitable speed (about 100 turns a minute) by turning the hand crank until the sample begins to tear and the pointer remains at rest on the dial plate. In the case of many stuffs, the continued TESTING THE STRENGTH AND ELASTICITY OF A FABRIC. movement of the hand crank, after tearing has begun, results in a further extension of the material before complete separa- tion is effected, which, however, cannot be regarded as in- creased elasticity. The manner of reading off the elasticity and breaking strain has already been indicated. Nevertheless, it should be remembered that the degrees of elasticity are not ex- pressed in millimetres as recorded on the scale, but as centi- metres, each fraction being reckoned as a whole number, because it may easily happen that in adjusting the sample by the hand the stuff is stretched rather more than is absolutely necessary. Before proceeding to a new test, the pointer must be re- adjusted opposite the zero mark on the dial, and the brass scale on the iron frame pushed back until its zero point is exactly on a level with the first clamp. After the machine has been lying idle for a long time it is advisable, before commencing the tests, to gradually stretch some solid body, such as zinc plate, several times (say, twice under a load of '200 kilos, and thrice under 80 kilos, tension) in the machine, in order to restore the spring to its normal length, since, when at rest, it is inclined to- alter (contract). It may be assumed that under a constant temperature a not unimportant alteration of this nature may occur within a few hours, and in a much shorter time under sudden fluctuations in the weather. When frost prevails the tests should be performed in a heated apartment, as the machine cannot yield accurate re- sults when under the influence of cold. As a rule, the room temperature is regulated to about 15 E. (68 F.), and the testing commenced only after the machine has been exposed to that temperature for one or two hours. From the results obtained with the test sample the breaking strain and elasticity of the material are calculated 140 YAENS AND TEXTILE FABRICS. to the total length (warp) and width (weft) of the piece of }42 }52 }, }.' t 50/51 [ 50/51 ) Unbleached grey tow 12 11 395-405 or 410-420 325-335 170-180 335-345 170-180 215-225 170-180 210-220 130-140 215-225 235-245 245-255 102-105 100-105 Un- bleached Un- bleached Un- bleached Un- bleached Yarn- white Yarn- white Re- bleached Re- bleached Re- bleached Creamed Yarn- white and dyed Yarn- white and dyed Yarn- white Yarn- white Un- mangled Un- mangled Un- ' mangled Un- mangled Un- maugled Un- mangled Medium mangling Medium mangling Un- mangled Un- mangled Un- mangled Un- mangled Lightly mangled Lightly mangled Unbleached grey tow Unbleached grey tow 10 12 12* 11 Unbleached grey tow Unbleached grey tow 10 20 121 14 Unbleached grey tow Unbleached grey tow 22 16 15^-16 14 Unbleached grey tow f bleached tow 16 18 15-16 16 | bleached tow f bleached tow 20 20 16 17 | bleached tow | bleached flax 20 25 17 21-22 | bleached flax | bleached flax 28 25 20-21 21-22 | bleached flax | bleached tow 28 20 20-21 21 | bleached tow Creamed tow 18 12 21-22 16 Creamed tow f bleached tow Fast indigo-dyed tow 12 18 20 15-151 16 | bleached tow Fast indigo -dyed tow J bleached flax Fast indigo-dyed flax 20 20 20 20 17-18 24 f bleached flax bleached flax 18 30 30 18 20-21 19-20 20-21 -| bleached flax bleached flax bleached flax 19-20 202 YARNS AND TEXTILE FABRICS. B. COTTONS. . ff Width in cm,. Kind of Yarn. Yarn No. No. of threads per 1 sq. cm. r. 11 fl 8,s tl be 01 fS 310-320 260-270 190-200 130-140 110-120 152-162 Finish. Whether un- bleached, creamed, re-bleached or dyed. Whether and to what extent mangled. Fustian for lining invalids' coats Bleached fustian for vests Calico for drawers Calico for in- valids' shirts Cotton cloth for neckcloths Blue and white checked cottons for ordinary bed and pillow covers 0, / 81 I 77 J 75/76 }7. };* }" Cotton Cotton Cotton Cotton Cotton f bleached Fast indigo-dyed 16-71 13-15 Un- bleached Bleached Un- bleached Bleached Bleached Yam- white and dyed Raised Raised Uu- niangled Lightly mangled Dressed Un- m angled 3-4 16-17 17-19 14-15 3-4 18-19 17-19 21-23 14-15 16-17 17-19 24-26 16-17 33-34 42-44 16 25-27 31-33 29-31 23-24 J bleached Fast indigo-dyed 16 '{ ' 23-24 C. WOOLLENS (FLANNEL). Flannel for bandages | 125 Carded yarn of German wool ll-lli 8-8J 20-21 320-330 Washed, fulled, lightly blued Evenly raised on both sides do. 15-16 The remarks on p. 190 apply equally in this case. For stuffs to be worked up in a shrunk state the loss in shrinking must be borne in mind. The regulations for taking delivery given on p. 191 also apply. The fastness of the blue checks must be tested by four or five washings. APPENDIX. 203 CONTRACT SPECIFICATIONS FOE, FRENCH ARMY CLOTHING. The new regulations issued in 1893 deal with the raw material, dyeing, fulling and dressing of the cloth. The raw material must consist of wool out of the centre of the fleece, partly of French origin and partly from Morocco, Algiers and Argentina, corresponding in staple to the type adopted by the Ministry of War. The wool must be care- fully sorted, cleaned and washed. The use of lamb's wool, skin wool, combings, shoddy, waste wool or cotton is strictly prohibited. Cleaning may be effected by the old or new (carbonisation) process, but in the latter case the strength of the acid used must not exceed 5 B. Scarlet, jonquil-yellow and maroon are piece-dyed, for which end the goods may be previously bleached with sul- phurous acid, bisulphite, or hydrogen peroxide, but all other colours must be dyed in the wool. Cochineal or lac dye is prescribed for scarlet ; wood for yellow ; sandal wood and madder for maroon. All shades of blue and grey must be vat-dyed, and must not contain any naturally yellow or dark wool. Eed may be dyed with madder or artificial alizarine, but the War Ministry reserves the right to prescribe more particularly in each individual case. For black the vat-dyed grey is to be finished with mineral salts and substances con- taining tannin. Only the very dark blue for non-com- missioned officers' uniforms may have a slight addition of sandal wood (but no campeachy) with ferrous sulphate and sumac. The use of modern dye stuffs is not prohibited so far as they are found to correspond in fastness to the requirements laid down. The wool after willowing must be carded three or four times and the yarn must be nicely and evenly twisted. 204 YARNS AND TEXTILE FABRICS. Power-loom weaving alone is admissible, hand weaving being disallowed. The woven fabric may be freed from fat either before or after fulling, according to the softening employed. After fulling, the cloth must not be artificially widened by stretching on the drying frame, and the sprinkling of the goods with glycerine, dissolved glue or vegetable mucilage is prohibited. Yellow and scarlet-coloured cloths must be decatired by steam, but they may be delivered without if the manufacturer is not installed for carrying out that operation. Length. The pieces after steaming must not be longer than 40 metres (43f yds.) nor less than 25 metres (27-f yds.), and the width between 137 and 143 cm. (54 to 56J in.). The selvedges, composed of twelve warp threads, must be 18 to 24 mm. (f to 1 in. nearly) wide after fulling. In the wool-dyed cloths they are to consist of white threads, other- wise of three black and nine threads of the ground colour of the cloth. In testing the weight of the cloth an average of 12*5 per cent, of moisture is considered normal (at 15 C. and in an atmosphere containing 80 to 90 per cent, of moisture). The weight per metre of cloth for non-commissioned officers' wear, 140 cm. (55 in.) wide, exclusive of the selvedges, is fixed at 720 grams (23J oz. per yd.) and the minimum breaking strain at 30 kilos. (66 Ibs.) for the warp and 22 kilos. (48'4 Ibs.) for the weft. UNIVERSITY INDEX. A. Alkalis, 47, 49. Alpaca, artificial, 33. wool, 31. Ammoniacal copper oxide, 44. Analysis of tissues, 147. Aniline sulphate solution, 47. Arsenic, estimating, 178. Artificial wools, 33. Atlas twills, 119, 120. Bast fibres, 14. Batiste, 120. Black dyes, 178. Blue dyes, 169. Breaking length, 97. strain of cloth, 94. testers, 128. Brocade, 121. Brown dyes, 129. Buckskin, 121. C. Calico, 120. Camel hair, 32 Cashmere wool, 31. Cassinet, 122. Cellulose, 15. Chappe silk, 41. reeling, 71. Chiffon, 120. Cloth testing, 118. weighing, 144. Cocoanut fibre, 26. Colorations, microchemical, 48. Colours, fastness of, 158. Combination of threads in weav- ing, 124. Conditioning apparatus, 110-117. Cordonnet, 89. Cosmos fibre, 26. Cotton, 16. dead, 17. yarn, numbering, 58. twist of, 84. Count of cloth, 141. Cows and calves' hair, 33. Creas, 120. D. Dissecting microscope, 9. Double twills, 119. Dye, estimation of, 168. Dynamometers, 128. Elasticity of cloth, 125. silk, 96. - yarn, 93, 96. tester, 99, 130, 136, 138. Embroidery silk, 89. Examination of mixed fibres, table of, 51. Extract wool, 33. F. Fastness against rain, 161. street mud, 161. to air, 162. to weather, 162. under friction, 160. washing, 159, (See also Kesistance.) Fat, percentage in yarn, 107. Figured fabrics, 119. Findeisen's conditioning appa- ratus, 117. 206 Flax, 18. Floconne, 121. Fnchsine solution, 46. G. German army clothing specifica- tions, 180. Glover's wool, 30. Green dyes, 170. Grege, 88. Grey dyes, 172. H. Hare and rabbit fur, 32. Heal's conditioning apparatus, 114. Hemp, 20. canvas, 122. Horse hair, 33. Hygroscopicity, determination of, 157. Hyparchia janira, 8. Imitation yarn, 1. Indigo dyes, 169. Iodine solution, 46. Ironing, resistance to, 163. J. Jute, 23. - fabrics, 120. - yarns, numbering, 64. K. Knapsack cloths, 196. Kohl's conditioning apparatus, 113. Linens, 121. and cottons for military use, 187. Linen yarns, numbering, 62. twist of, 86. Llama wool, 31. YARNS AND TEXTILE FABRICS. M. Manila hemp, 25. Marabout silk, 89. Measuring machines, 164. Micrometer, 10. Microscope, 3-12. eye-piece, 4, 7. objective, 4, 7. judging, 8. test objects, 8. Mode colours, 172. Modes of weaving, testing, 124. Mohair, 122. wool, 30. Moisture, determination of, 108. Mollinos, 120. Mordants, estimation of, 165. Mungo, 33. N. Naphthol solution, 47. Nettle fibre, 22. yarn, numbering, 65. New Zealand flax, 26. Nickel solution, 46. Organzine, 89. Orleans, 122. 0. P. Packing cloths, 120. Percale, 120. Phloroglucin solution, 47. Piece goods, length of, 164. Pleurosigma angulatum, 9. Foil silk, 89. Polarising apparatus, 11. Poplin, 122. Preparing sections, 13. Provision bags, cloth for, 196. Quality numbers, 93. Quantitative analysis of fabrics, 110. INDEX. 207 R. Ramie, 22. Haw silk, 88. Reeling, various standards of, 57-72. Repp, 122. Reprise, 109. Resistance to ironing, 163. - perspiration, 160. steaming, 163. S. Salts, solutions of, 48. Sampling reel, 77. Semi-taffeta, 122. Separation of wool from cotton, etc., 52-54. Serge, 121. Sewing silk, 89. Sheep's wool, 29. Shoddy yarn, 1. Shoe canvas, 192. Shotting, count of, 141. Shrinkage, 143. Silk, 39. - artificial, 43. - cordonnet, 89. loaded, 42. loading, 55. spun, 41. - wild, 41. Sodium copper oxide, 45. Steaming, resistance to, 163. Stiffened linens, 120. Sulphuric acid, 46, 47, 50. T. Tanner's wool, 30. Tenacity, 127. Tent canvas, 199. Thibet wool, 31. Thickness of cloth, 143. Thread counter, 125. Tussah silk, 41. Twills, 119, 120. Twist, 1. counter, 91. tester, 90. U. Ulmann's conditioning appara- tus, 115, 116. Unions, 122. V. Vegetable fibres, 14. Velvety fabrics, 120. Vicuna wool, 31. yarn, 1. W. Waterproof cloth for troops, 192. testing, 154. Weavings, plain or smooth, 89. Wool, kinds of, 27. muslin, 121. Woollen yarn, numbering, 66. twist of, 86. Y. Yarn, balances for weighing, 72- 77. doubled, 2. external appearance of, 81. length of, 79. number, determining, 57. tensile strength of, 93. testers, 81, 97-106. testing, 2. twisted, 2. uniformity of, 94. Yellow and orange dyes, 172. Zanella, 121. Zinc chloride solution, 46. , ABERDEEN UNIVERSITY PRESS. A CATALOGUE OF Special Technical Works FOR Coffeges find fTecflnicaf -Scfloofs . * : BY EXPERT WRITERS FOR THE Oil, Grease, Taint, Colour, Varnish, Soap, Candle, Chemical, Textile, Leather, Tottery, Glass, Plumbing and Decorating Trades and Scientific Professions* PUBLISHED BY SCOTT, GREENWOOD & CO., TECHNICAL LITERATURE AND TRADE JOURNAL EXPERTS, 19 LUDGATE HILL, LONDON, E.G. Telegraphic Address : " PRINTERIES, LONDON ". Telephone No, 5403, Bank. N.B. Full Particulars of Contents of any of the following books sent post free on application. Books on Oils, Soaps, Colours, Glue, Varnishes, etc. THE PRACTICAL COMPOUNDING OF OILS, TALLOW AND GREASE FOR LUBRICATION, ETC. By AN EXPERT OIL REFINER. Price : United Kingdom, 7s. 6d. ; Continent, 9s., post free. Contents. Chapters I., Introductory Remarks on the General Nomenclature of Oils, Tallow and Greases suitable for Lubrication. II., Hydrocarbon Oils. III., Animal and Fish Oils. IV., Compound Oils. V., Vegetable Oils. VI., Lamp Oils. VII., Engine Tallow, Solidified Oils and Petroleum Jelly. VIII., Machinery Greases: Loco and Anti- friction. IX., Clarifying and Utilisation of Waste Fats, Oils, Tank Bottoms, Drainings of Barrels and Drums, Pickings Up, Dregs, etc. X., The Fixing and Cleaning of Oil Tanks, etc. Appendix of General Information. Press Opinions. " This work is written from the standpoint of the oil trade, but its perusal will be found very wseful by users of machinery and all who have to do with lubricants in any way." Colliery 'Guardian. " The properties of the different grades of mineral oil and of the animal and vegetable non- drying oils are carefully described, and the author justly insists that the peculiarities of the machinery on which the lubricants are to be employed must be considered almost before every- thing else. . . . The chapters on grease and solidified oils, etc., are excellent." The Ironmonger. " In its ninety-six pages this little work contains a wealth of information ; it is written without waste of words on theoretical matters, and contains numerous formulas for a great variety of compounds for the most varied lubricants. In addition there are many practical hints of use in i the factory in general, such as of tanks, etc., and altogether the book is worth several times its , price in any factory of these compounds." American Soap Journal. LSOAPS. A Practical Manual of the Manufacture of Domestic, Toilet and other Soaps. By GEORGE H. HURST, F.C.S. Illustrated with 66 Engravings. Price 12s. 6d. ; Germany, 14 mks. ; France and Belgium, 16 frs., post free. Contents. Chapters I., Introductory. II., Soap-maker's Alkalies. III., Soap Fats and Oils. IV., Perfumes. V., Water as a Soap Material. VI., Soap Machinery. VII., Tech- nology of Soap-making. VIII., Glycerine in Soap Lyes. IX., Laying out a Soap Factory. X., Soap Analysis. Appendices. Press Opinions. s " Much useful information is conveyed in a convenient and trustworthy manner which will appeal to practical soap-makers." Chemical Trade Journal. This is a better book on soap-manufacture than any of the same size which have been published tor some time. It reads like the ' real thing,' and gives a very complete account of the technique of soap-making, especially of the machinery employed, the different methods and even the arrangement of soap factories. . . . The book is produced well, and is splendidly illus- trated " Chemist and Druggist. " The best and most reliable methods of analysis are fully discussed, and form a valuable source of reference to any work's chemist. . . . Our verdict is a capitally-produced book, and one that is badly needed." Birmingham Post. " We think it is the most practical book on these subjects that has come to us from England so far." American Soap Journal. " Works that deal with manufacturing processes, and applied chemistry in particular, are always welcome. Especially is this the case when the material presented is so up-to-date as we find it here." Bradford Observer. ANIMAL FATS AND OILS : Their Practical Production, Puri- fication and Uses for a Great Variety of Purposes. Their Properties, Falsification and Examination. A Handbook for Manufacturers of Oil and Fat Products, Soap and Candle Makers, Agriculturists, Tanners, Margarine Manufacturers, etc., etc. By Louis EDGAR ANDES. With 62 Illustrations. Price 10s. 6d. ; France and Belgium, 13 frs. ; Colonies, 12s., post free. Contents. Introduction. Occurrence, Origin, Properties and Chemical Constitution of Animal Fats. Preparation of Animal Fats and Oils. Machinery. Tallow-melting Plant. Extraction Plant. Presses. Filtering Apparatus. Butter : Raw Material and Preparation, Properties, Adult- erations, Beef Lard or Remelted Butter, Testing. Candle-fish Oil. Mutton Tallow. Hare Fat. Goose Fat. Neatsfoot Oil. Bone Fat: Bone Boiling, Steaming Bones, Extraction, Refining. Bone Oil. Artificial Butter: Oleomargarine, Margarine Manufacture in France, Grasso's Process. " Kaiser's Butter," Jahr & Miinzberg's Method, Filbert's Process, Winter's Method. Human Fat. Horse Fat. Beef Marrow. Turtle Oil. Hog's Lard : Raw Material, Preparation, Properties, Adulterations, Examination. Lard Oil. Fish Oils. Liver Oils. Artificial Train Oil. Wool Fat: Properties, Purified Wool Fat. Spermaceti: Examination of Fats and Oils in General. Press Opinions. " The latest and most improved forms of machinery are in all cases indicated, and the many advances which have been made during the past years in the methods of producing the more common animal fats lard, tallow and butter receive due attention." Glasgow Herald. " The work is very fully illustrated, and the style throughout is in strong contrast to that mp'.oyed in many such treatises, being simple and clear." Shoe and Leather Rem-d " An important handbook for the ' fat industry," now a large one. The explanation of the most scientific processes of production lose nothing of their clearness in the translation." Newcastle Chronicle. " It is a valuable work, not only for the student, but also for the practical manufacturer of oil and fat products.." Journal of the American Chemical Society. " The descriptions of technical processes are clear, and the book is well illustrated and should prove useful." Manchester Guardian. VEGETABLE FATS AND OILS : Their Practical Preparation, Purification and Employment for Various Purposes, their Properties, Adulteration and Examination. A Handbook for Oil Manufacturers and Refiners, Candle, Soap and Lubricating Oil Makers, and the Oil and Fat Industry in General. Translated from the German of Louis EDGAR ANDES. With 94 Illustrations. Price 10s. 6d. ; Germany, 12 mks. ; France and Belgium, 13 frs. ; Colonies, 12s. post free. Contents. Statistical Data. General Properties of the Vegetable Fats and Oils. Estimation of the Amount of Oil in Seeds. Table of Vegetable Fats and Oils, with French and German Nomenclature, Source and Origin and Percentage of Fat in the Plants from which they are Derived. The Preparation of Vegetable Fats and Oils: Storing Oil Seeds; Cleaning the Seed. Apparatus for Grinding Oil Seeds and Fruits. Installation of Oil and Fat Works. Ex- traction Method of Obtaining Oils and Fats. Oil Extraction Installations. Press Moulds. Non-drying Vegetable Oils. Vegetable Drying Oils. Solid Vegetable Fats. Fruits Yielding Oils and Fats. Wool-softening Oils. Soluble Oils. Treatment of the Oil after Leaving the Press. Improved Methods of Refining with Sulphuric Acid and Zinc Oxide or Lead Oxide. Refining with Caustic Alkalies, Ammonia, Carbonates of the Alkalies, Lime. Bleaching Fats and Oils. Practical Experiments on the Treatment of Oils with regard to Refining and Bleaching. Testing Oils and Fats. Press Opinions. " Concerning that and all else within the wide and comprehensive connexion involved, this book must be invaluable to every one directly or indirectly interested in the matters it treats. of." Commerce. " The proprietors of the Oil and Colourman's Journal have not only placed a valuable and highly interesting book of reference in the hands of the fats and oils industry in general, but have rendered no slight service to experimental and manufacturing chemists." Manufacturing Chemist. LUBRICATING OILS, FATS AND GREASES : Their Origin, Preparation, Properties, Uses and Analyses. A Handbook for Oil Manufacturers, Refiners and Merchants, and the Oil and Fat Industry in General. By GEORGE H. HURST, F.C.S. Price 10s. 6d. ; Germany,. 12 mks. ; France and Belgium, 13 frs. ; Colonies, 12s., post free. Contents. Chapters I., Introductory. Oils and Fats, Fatty Oils and Fats, Hydrocarbon Oils, Uses of Oils. II., Hydrocarbon Oils. Distillation, Simple Distillation, Destructive Distillation, Products of Distillation, Hydrocarbons, Paraffins, Olefins, Naphthenes. III., Scotch Shale Oils. Scotch Shales, Distillation of Scotch Oils, Shale Retorts, Products of Distilling Shales, Separating Products, Treating Crude Shale Oil, Refining Shale Oil, Shale Oil Stills, Shale Naptha Burning Oils, Lubricating Oils, Wax. IV., Petroleum. Occurrence, Geology, Origin, Composition, Extraction, Refining, Petroleum Stills, Petroleum Products, Cylinder Oils, Russian Petroleum, Deblooming Mineral Oils. V., Vegetable and Animal Oils. Introduction, Chemical Composition of Oils and Fats, Fatty Acids, Glycerine, Extraction of Animal and Vegetable Fats and Oils, Animal Oils, Vegetable Oils, Rendering, Pressing, Refining, Bleaching, Tallow, Tallow Oil, Lard Oil, Neatsfoot Oil, Palm Oil, Palm Nut Oil, Cocoanut Oil, Castor Oil, Olive Oil, Rape and Colza Oils, Arachis Oil, Niger Seed Oil, Sperm Oils, Whale Oil, Seal Oil, Brown Oils, Lardine, Thickened Rape Oil. VI., Testing and Adulteration of Oils. Specific Gravity, Alkali Tests, Sulphuric Acid Tests, Free Acids in Oils, Viscosity Tests, Flash and Fire Tests, Evaporation Tests, Iodine and Bromide Tests, Elaidin Test, Melting Point of Fat, Testing Machines. VII., Lubricating Greases. Rosin Oil, Anthracene Oil, Making Greases, Testing and Analysis of Greases. VIII., Lubrication. Friction and Lubrication, Lubricant, Lubrication of Ordinary Machinery, Spontaneous Combustion of Oils, Stainless Oils, Lubrication of Engine Cylinders, Cylinder Oils. Appendices. A. Table of Baume's Hydrometer B. Table of Thermometric Degrees C. Table of Specific Gravities of Oils. Index. Press Opinions. " This is a clear and concise treatment of the method of manufacturing and refining lub- ricating oils. . . . The book is one which is well worthy the attention of readers who are users of oil." Textile Recorder. " The book is well printed, and is a credit alike to author, printer and publisher." Textile Mercury. " Mr. Hurst has in this work supplied a practical treatise which should prove of especial value to oil dealers and also, though in a less degree, of oil users." Textile Manufacturer. " A mere glance at the table of contents is sufficient to show how various are the conditions to which these materials have to be applied, how much knowledge is required for the selection of the right kind for each particular purpose, and how by processes of mixture or manufacture the requisite qualities are obtained in each case." Manchester Guardian. " This valuable and useful work, which is both scientific and practical, has been written with a view of supplying those who deal in and use oils, etc., for the purpose of lubrication with some information respecting the special properties of the various products which cause these various oils to be of value as lubricants." Industries and Iron. "We have no hesitation in saying that in our opinion this book ought to be very useful to all those who are interested in oils, whether as manufacturers or users of lubricants, or to those chemists or engineers whose duty it may be to report upon the suitability of the same for any particular class of work." Engineer. " The author is. widely known and highly respected as an authority on the chemistry of oils and the technics of lubrication, and it is safe to say that no work of similar interest or equal value to the general oil-selling and consuming public has heretofore appeared in the English language." Drugs, Oils and Paints, U.S.A. " It will be a valuable addition to the technical library of every steam user's establishment." Machinery Market. THE MANUFACTURE OF VARNISHES, OIL REFINING AND BOILING, AND KINDRED INDUSTRIES. Describing the Manufacture of Spirit Varnishes and Oil Varnishes ; Raw Materials : Resins, Solvents and Colouring Principles ; Drying Oils : their Pro- perties, Applications and Preparation by both Hot and Cold Processes; Manufacture, Employment and Testing of Different Varnishes. Trans- lated from the French of ACH. LIVACHE. Greatly Extended and Adapted to English Practice, with numerous Original Recipes. By J. G. MclNTOSH, Lecturer on Oils, Colours and Varnishes. Price 12s. 6d. France and Belgium, 16 frs. ; Colonies, 14s., post free. Contents. I. Resins : Gum Resins, Oleo Resins and Balsams, Commercial Varieties, Source, Collection, Characteristics, Chemical Properties, Physical Properties, Hardness, Adulterations, Appro- priate Solvents, Special Treatment, Special Use. II. Solvents: Natural, Artificial, Manufac- ture, Storage, Special Use. III. Colouring : Principles, (i) Vegetable, (2) Coal Tar, (3) Coloured Resinates, (4) Coloured Oleates and Linoleates. Gum Running: Furnaces, Bridges, Flues, Chimney Shafts, Melting Pots, Condensers, Boiling or Mixing Pans, Copper Vessels, Iron Vessels (Cast), Iron Vessels (Wrought), Iron Vessels (Silvered), Iron Vessels (Enamelled), Steam Superheated Plant, Hot-air Plant. Spirit Varnish Manufacture : Cold Solution Plant, Mechanical Agitators, Hot Solution Plant, Jacketted Pans, Mechanical Agitators, Clarification and Filtration, Bleaching Plant, Storage Plant. Manufacture, Characteristics and Uses of the Spirit Varnishes yielded by : Amber, Copal, Dammar, Shellac, Mastic, Sandarac, Rosin, Asphalt, India Rubber, Gutta Percha, Collodion, Celluloid, Resinates, Oleates. Manufacture of Varnish Stains. Manufacture of Lacquers. Manufacture of Spirit Enamels. Analysis of Spirit Var- nishes. Physical and Chemical Constants of Resins. Table of Solubility of Resins in different Influence on Seed and Oil. Oil Refining: Processes, Thenard's, Liebig's, Filtration, Storage, Old Tanked Oil. Oil Boiling: Fire Boiling Plant, Steam Boiling Plant, Hot-air Plant, Air Pumps, Mechanical Agitators, Vincent's Process, Hadfield's Patent, Storer's Patent, Walton's Processes, Continental Processes, Pale Boiled Oil, Double Boiled Oil, Hartley and Blenkinsop's Process. Driers: Manufacture, Special Individual Use of (i) Litharge, (2) Sugar of Lead, (3) Red Lead, (4) Lead Borate, (5) Lead Linoleate, (6) Lead Resinate, (7) Black Oxide of Man- ganese, (8) Manganese Acetate, (9) Manganese Borate, (10) Manganese Resinate, (n) Manganese Linoleate, Mixed Resinates and Linoleates, Manganese and Lead, Zinc Sulphate, Terebine, Liquid Driers. Solidified Boiled Oil. Manufacture of Linoleum. Manufacture of India Rubber Substitutes. Printing Ink Manufacture. Lithographic Ink Manufacture. Manufacture of Oil Varnishes. Running and Special Treatment of Amber, Copal, Kauri, Manilla. Addition of Oil to Resin. Addition of Resin to Oil. Mixed Processes. Solution in Cold of previously fused Resin. Dissolving Resins in Oil, etc., under pressure. Filtration. Clarification. Storage. Ageing. Coachmakers' Varnishes and Japans. Oak Varnishes. Japanners' Stoving Varnishes. Japanners' Gold Size. Brunswick Black. Various Oil Varnishes. Oil-Varnish Stains. Varnishes for " Enamels ". India Rubber Varnishes. Varnishes Analysis : Pro- cesses, Matching. Faults in Varnishes : Cause, Prevention. Experiments and Exercises. Press Opinions. " There is no question that this is a useful book." Chemist and Druggist. " The different formulas which are quoted appear to be far more ' practical ' than such as are usually to be found in text-books ; and assuming that the original was published two or three years ago, and was only slightly behindhand in its information, the present volume gives a fair insight into the position of the varnish industry." The Ironmonger. THE TESTING AND VALUATION OF RAW MATERIALS USED IN PAINT AND COLOUR MANUFACTURE. By M. W. JONES, F.C.S. A book for the laboratories of colour works. Price 5s. ; Colonies and Continent, 6s., strictly net, post free. Contents. Aluminium Compounds. China Clay. Iron Compounds. Potassium Compounds. Sodium Compounds. Ammonium Hydrate. Acids. Chromium Compounds. Tin Compounds. Copper Compounds. Lead Compounds. Zinc Compounds. Manganese Compounds. Arsenic Com- pounds. Antimony Compounds. Calcium Compounds. Barium Compounds. Cadmium Compounds. Mercury Compounds. Ultramarine. Cobalt and Carbon Compounds. Oils. Index. THE CHEMISTRY OF ESSENTIAL OILS AND ARTIFI- CIAL PERFUMES. By ERNEST J. PARRY, B.Sc. (Lond.), F.I.C., F.C.S. Illustrated with 20 Engravings. 400 pp. Price 12s. 6d. ; Abroad, 14s., strictly net, post free. Contents. Chapters I., The General Properties of Essential Oils. II., Compounds occurring in Essential Oils. III.. The Preparation of Essential Oils. IV., The Analysis of Essential Oils. V., Systematic Study of the Essential Oils. VI., Terpeneless Oils. VII., The Chemistry of Artificial Perfumes. Appendix : Table of Constants. Press Opinions. " At various times monographs have been printed by individual workers, but it may safely be said that Mr. Parry is the first in these latter days to deal with the subject in an adequate manner. His book is well conceived and well writi en. . . . He is known to have sound practical experience in analytical methods, and he has apparently taken pains to make himself an fait with the commercial aspects of the subject." Chemist and DfUggist. " We can heartily recommend this volume to all interested in the subject of essential oils from the scientific or the commercial standpoint." British and Colonial Druggist. " There can be no doubt that the publication will take a high place in the list of scientific text-books." London Argus. " A most useful appendix is inserted, giving a table of constants for the more important essential oils. . . . This, in itself, is of sufficient importance and use to warrant the publication of the book, and, added to the very complete classification and consideration of the essential oils which precedes it, the volume becomes of great value to all interested." Glasgow Herald. " Mr. Parry has done good service in carefully collecting and marshalling the results of the numerous researches published in various parts of the world." Pharmaceutical Journal. COLOUR: A HANDBOOK OF THE THEORY OF COLOUR. By GEORGE H. HURST, F.C.S. With 10 coloured Plates and 72 Illus- trations. Price 7s. 6d. ; Abroad, 9s., post free. Contents. Chapters I.. Colour and its Production. II., Cause of Colour in Coloured Bodies. III., Colour Phenomena and Theories. IV., The Physiology of Light. V., Contrast. VI., Colour in Decoration and Design. VII., Measurement of Colour. Press Opinions. " This is a workmanlike technical manual, which explains the scientific theory of colour in terms intelligible to everybody. ... It cannot but prove both interesting and instructive to all classes of workers in colour." Scotsman. " Mr. Hurst's Handbook on the Theory of Colour will be found extremely useful, not only to the art student, but also to the craftsman, whose business it is to manipulate pigments and dyes." Nottingham Daily Guardian. " It is thoroughly practical, and gives in simple language the why and wherefore of the many colour phenomena which perplex the dyer and the colourist." Dyer and Calico Printer. " We have found the book very interesting, and can recommend it to all who wish to master the different aspects of colour theory, with a view to a practical application of the knowledge so gained." Chemist and Druggist. " It will be found to be of direct service to the majority of dyers, calico printers and colour mixers, to whom we confidently recommend it." Chemical Trade Journal. " This useful little book possesses considerable merit, and will be of great utility to those for whom it is primarily intended." Birmingham Post. IRON-CORROSION, ANTI-FOULING AND ANTI- CORROSIVE PAINTS. By Louis EDGAR ANDES. Sixty-two Illustrations. Translated from the German. Price 10s. 6d. ; Abroad, 12s., strictly net, post free. Contents. Ironrust and its Formation Protection from Rusting by Paint Grounding the Iron with Linseed Oil, etc. Testing Paints Use of Tar for Painting on Iron Anti-corrosive Paints Linseed Varnish Chinese Wood Oil Lead Pigments Iron Pigments Artificial Iron Oxides Carbon Preparation of Anti-corrosive Paints Results of Examination of Several Anti- corrosive Paints Paints for Ship's Bottoms Anti-fouling Compositions Various Anti-cor- rosive and Ship's Paints Official Standard Specifications for Ironwork Paints Index. 8 THE LEATHER WORKER'S MANUAL. Being a Com- pendium of Practical Recipes and Working Formulae for Curriers, Bootmakers, Leather Dressers, Blacking Manufacturers, Saddlers, Fancy Leather Workers, and all Persons engaged in the Manipulation of Leather. By H. C. STANDAGE. Price 7s. 6d. ; Abroad, 9s., strictly net, post free. Contents. Chapters I., Blackings, Polishes, Glosses, Dressings, Renovators, etc., for Boot and Shoe Leather. II., Harness Blackings, Dressings, Greases, Compositions, Soaps, and Boot-top Powders and Liquids, etc., etc. III., Leather Grinders' Sundries. IV., Currier's Seasonings, Blacking Compounds, Dressings, Finishes, Glosses, etc. V., Dyes and Stains for Leather. . VI., Miscellaneous Information. VII., Chrome Tannage. Index. Press Opinions. "The book being absolutely unique, is likely to be of exceptional value to all whom it con- cerns, as it meets a long-felt want." Birmingham Gazette. " This is a valuable collection of practical receipts and working formulae for the use of those engaged in the manipulation of leather. We have no hesitation in recommending it as one of the best books of its kind, an opinion which will be endorsed by those to whom it appeals." Liverpool Mercury. GLUE AND GLUE TESTING. By SAMUEL RIDEAL, D.Sc. Lond., Fellow of the Institute of Chemistry, Vice-President of the Society of Public Analysts, Author of " Water and its Purification," " Disinfection and Disinfectants ". Illustrated with fourteen Engravings. Price 10s. 6d., strictly net; United States, 3 dols. ; Germany, 12 mks. ; France and Belgium, 13 frs., post free. Contents. Chapters I., Constitution and Properties: Definitions, Sources, Gelatine, Chondrin and Allied Bodies, Physical and Chemical Properties, Classification, Grades and Commercial Varieties. II., Raw Materials and Manufacture : Glue Stock, Lining, Extraction, Washing and Clarifying, Filter Presses, Water Supply, Use of Alkalies, Action of Bacteria and of Antiseptics, Various Processes, Cleansing, Forming, Drying, Crushing, etc., Secondary Products. III., Uses of Glue: Selection and Preparation for Use, Carpentry, Veneering, Paper Making, Book-binding, Printing Rollers, Hectographs, Match Manufacture, Sandpaper, etc., Substitutes for other Materials, Artificial Leather and Caoutchouc. IV., Gelatine : General Characters, Liquid Gelatine, Photographic Uses, Size, Tanno- Chrome, and Formo- Gelatine, Artificial Silk, Cements, Pneumatic Tyres, Culinary, Meat Extracts, Isinglass, Medicinal and other Uses, Bacteriology. V., Glue Testing:: Review of Processes, Chemical Examination, Adulteration, Physical Tests, Valuation of Raw Materials. VII., Commercial Aspects. Books on Pottery, Glass, etc. THE MANUAL OF PRACTICAL POTTING. Price 17s. 6d ; Colonies and Continent, 18s., post fr^ .. Contents. Introduction. The Rise and Progress of the Potter's Art. Chapters I., Bodies. China and Porcelain Bodies, Parian Bodies, Semi-porcelain and Vitreous Bodies, Mojter Bodies, Earthenwares Granite and C.C. Bodies, Miscellaneous Bodies, Sagger and Crucible Clays, Coloured Bodies, Jasper Bodies, Coloured Bodies for Mosaic Painting, Encaustic Tile Bodies, Body Stains, Coloured Dips. II., Glazes. China Glazes, Ironstone Glazes, Earthenware Glazes, Glazes without Lead, Miscellaneous Glazes, Coloured Glazes, Majolica Colours. III., Gold and Cold Colours. Gold, Purple of Cassius, Marone and Ruby, Enamel Colour Bases, Enamel Colour Fluxes, Enamel Colours, Mixed Enamel Colours, Antique and Vellum Enamel Colours, Underglaze Colours, Underglaze Colour Fluxes, Mixed Underglaze Colours, Flow Powders, Oils and Varnishes. IV., Means and Methods. Reclamation of Waste Gold, The Use of Cobalt, Notes on Enamel Colours, Liquid or Bright Gold. V., Classification and Analysis. Classification of Clay Ware, Lord Playfair's Analysis of Clays, The Markets of the World, Time and Scale of Firing, Weights of Potter's Material, Decorated Goods Count. VI., Comparative Loss of Weight of Clays. VII., Ground Felspar Calculations. VIII., The Conversion of Slop Body Recipes into Dry Weight. IX., The Cost of Prepared Earthenware Clay. X., Forms and Tables. Articles of Apprenticeship, Manufacturer's Guide to Stock- taking, Table of Relative Values of Potter's IWaterials, Hourly Wages Table, Workman's Settling Table, Comparative Guide for Earthenware and China Manufacturers in the Use of Slop Flint and Slop Stone, Foreign Terms applied to Earthenware and China Goods, Table for the Conversion of Metrical Weights and Measures on the Continent of South America. CERAMIC TECHNOLOGY : Being some Aspects of Technical Science as Applied to Pottery Manufacture. Edited by CHARLES F. BINNS. Price 12s. 6d. ; Colonies and Continent, 14s., post free. Contents. Preface. Introduction. Chapters I., The Chemistry of Pottery II., Analysis and Syn- thesis. III., Clays and their Components. IV., The Biscuit Oven. V., Pyrometry. VI., Glazes and their Composition. VII., Colours and Colour-makingindex. COLOURING AND DECORATION OF CERAMIC WARE. By ALEX. BRONGNIART. With Notes and Additions by ALPHONSE SALVETAT. Translated 'from the French. The writings of Brongniart marked an epoch in ceramic literature, and are now for the first time offered in book form in English. Any potter or workman who is in any way interested in ceramic ware, glazes or enamels will find this work a perfect mine of information. Hundreds of receipts for making and applying colours, glazes and enamels, -firing, etc. Bound in Cloth. 200 pages. Price 7s. 6d., strictly net, post free. HOW TO ANALYSE CLAY. Practical Methods for Practical Men. By HOLDEN M. ASHBY, Professor of Organic Chemistry. Price 2s. 6d., strictly net, post free. THE ART OF RIVETING GLASS, CHINA AND EARTHEN- WARE. By J. HOWARTH. Price Is. ; by post, Is. 2d. PAINTING ON GLASS AND PORCELAIN AND ENAMEL PAINTING. A Complete Introduction to the Preparation of all the Colours and Fluxes used for Painting on Porcelain, Enamel, Faience and Stoneware, the Coloured Pastes and Coloured Glasses, together with a Minute Description of the Firing of Colours and Enamels. On the Basis of Personal Practical Experience of the Condition of the Art up to Date. By FELIX HERMANN, Technical Chemist. With 18 Illus- trations. Second, greatly Enlarged, Edition. Price 10s. 6d. ; Ger- many, 12 mks. ; France and Belgium, 13 frs., post free. Contents. History of Glass Painting. Chapters I., The Articles to be Painted: Glass, Porcelain, Enamel, Stoneware, Faience. II., Pigments: i, Metallic Pigments: Antimony Oxide, Naples Yellow, Barium Chromate, Lead Chromate, Silver Chloride, Chromic Oxide. III., Fluxes: Fluxes, Felspar, Quartz, Purifying Quartz, Sedimentation, Quenching, Borax, Boracic Acid, Potassium and Sodium Carbonates, Rocaille Flux. IV., Preparation of the Colours for Glass Painting. V., The Colour Pastes. VI., The Coloured Glasses. VII., Composition of the Porcelain Colours. VIII., The Enamel Colours: Enamels for Artistic Work. IX., Metallic Ornamentation: Porcelain Gilding, Glass Gilding. X., Firing the Colours: i, Remarks on Firing: Firing Colours on Glass, Firing Colours on Porcelain; 2, The Muffle. XI., Accidents occasionally Supervening during the Process of Firing. XII., Remarks on the Different Methods of Painting on Glass, Porcelain, etc. Appendix : Cleaning Old Glass Paintings. Press Opinions. " A reliable treatise on the preparation of the colours and fluxes, with exhaustive quantitative recipes, and minute descriptions of the firing of colours and enamels, is of no small technical importance, and emanating from so distinguished an authority as Felix Hermann, Brongniart's successor in the direction of the S&vres manufactory, merits the earnest study of all engaged in the porcelain and kindred industries in England. ... In every district of England where art porcelain and glass is manufactured this treatise should be widely circulated, and its contents made familiar to all engaged, in whatever capacity, in the trade." Leeds Mercury. " The whole cannot fail to be both of interest and service to glass workers and to potters generally, especially those employed upon high-class work." Staffordshire Sentinel. 10 A Reissue of THE HISTORY OF THE STAFFORDSHIRE POTTERIES; AND THE RISE AND PROGRESS OF THE MANUFACTURE OF POTTERY AND PORCELAIN. With References to Genuine Specimens, and Notices of Eminent Potters. By SIMEON SHAW. (Originally Published in 1829.) Price 7s. 6d., strictly net, post free ; Abroad, 9s. Contents. Introductory Chapter showing the position of the Pottery Trade at the present time (1899). Chapters I., Preliminary Remarks. II., The Potteries, comprising Tunstall, Brownhills, Greenfield and New Field, Golden Hill, Latebrook, Green Lane, Burslem, Longport and Dale Hall, Hot Lane and Cobridge, Hanley and Shelton, Etruria, Stoke, Penk- hull, Fenton, Lane Delph, Foley, Lane End. III., On the Origin of the Art, and its Practice among the early Nations. IV., Manufacture of Pottery, prior to 1700. V., The Introduction of Red Porcelain by Messrs. Elers, of Bradwell, 1690. VI., Progress of the Manufacture from 1700 to Mr. Wedgewood's commencement in 1760. VII., Introduc= tion of Fluid Qlaze. Extension of the Manufacture of Cream Colour. Mr. Wedgwood's Queen's Ware. Jasper, and Appointment of Potter to her Majesty. Black Printing. VIII., Introduction of Porcelain. Mr. W. Littler's Porcelain. Mr, Cookworthy's Discovery of Kaolin and Petuntse, and Patent. Sold to Mr. Champion resold to the New Hall Com. Extension of Term. IX., Blue Printed Pottery- Mr. Turner, Mr. Spode (i), Mr. Baddeley, Mr. Spode (2), Messrs. Turner, Mr. Wood, Mr. Wilson, Mr. Minton. Great Change in Patterns of Blue Printed. X., Introduction of Lustre Pottery. Improvements in Pottery and Porcelain subsequent to 1800. Press Opinions. " This work is all the more valuable because it gives one an idea of the condition of affairs existing in the north of Staffordshire before the great increase in work and population due to modern developments." Western Morning News. " The book will be especially welcomed at a time when interest in the art of pottery manu- facture commands a more widespread and general interest than at any previous time." Wolver- hampton Chronicle. " Copies of the original work are now of considerable value, and the facsimile reprint now issued cannot but prove of considerable interest to all interested in the great industry." Derby Mercury. " There is much curious and useful information in the work, and the publishers have rendered the public a service in reissuing it." Burton Mail. A Reissue of THE CHEMISTRY OF THE SEVERAL NATURAL AND ARTIFICIAL HETEROGENEOUS COM- POUNDS USED IN MANUFACTURING PORCELAIN, GLASS, AND POTTERY. By SIMEON SHAW. (Originally Published in 1837.) Price 17s. 6d. ; Colonies and Continent, 18s., strictly net, post free. Contents. PART I., ANALYSIS AND MATERIALS Chapters I., Introduction : Laboratory and Apparatus ; Elements : Combinative Potencies, Manipulative Processes for Analysis and Reagents, Pulverisation, Blow-pipe Analysis, Humid Analysis, Preparatory Manipulations, General Analytic Processes, Compounds Soluble in Water, Compounds Soluble only in Acids, Compounds (Mixed) Soluble in Water, Compounds (Mixed) Soluble in Acids, Compounds (Mixed) Insoluble, Particular Analytic Processes II., Temperature : Coal, Steam Heat for Printers' Stoves III., Acids and Alkalies : Boracic Acid, Muriatic Acid, Nitric Acid, Sul- phuric Acid, Potash, Soda, Lithia, Calculation of Chemical Separations IV., The Earths : t, Arsenite of Cobalt, Copper, Gold, Iron, Lead, Manganese, Platinum, Silver, Tin, Zinc. 11 PART II., SYNTHESIS AND COMPOUNDS. Chapters I., Sketch of the Origin and Progress of the Art II., Science of Mixing : Scientific Principles of the Manufacture, Com- binative Potencies of the Earths. III., Bodies: Porcelain Hard, Porcelain Fritted Bodies, Porcelain Raw Bodies, Porcelain Soft, Fritted Bodies, Raw Bodies, Stone Bodies, Ironstone, Dry Bodies, Chemical Utensils, Fritted Jasper, Fritted Pearl, Fritted Drab, Raw Chemical Utensils, Raw Stone, Raw Jasper, Raw Pearl, Raw Mortar, Raw Drab, Raw Brown Raw Fawn, Raw Cane, Raw Red Porous, Raw Egyptian, Earthenware, Queen's Ware, Cream Colour, Blue and Fancy Printed, Dipped and Mocha, Chalky, Rings, Stilts, etc. IV., Glazes: Porcelain Hard Fritted, Porcelain Soft Fritted, Porcelain Soft Raw, Cream Colour Porcelain, Blue Printed Porcelain, Fritted Glazes, Analysis of Fritt, Analysis of Glaze, Coloured Glazes, Dips, Smears, and Washes; Glasses: Flint Glass, Coloured Glasses, Artificial Garnet, Artificial Emerald, Artificial Amethyst, Artificial Sapphire, Artificial Opal, Plate Glass, Crown Glass, Broad Glass, Bottle Glass, Phosphoric Glass, British Steel Glass, Glass-Staining and Painting, Engraving on Glass, Dr. Faraday's Experiments. V., Colours: Colour Making, Fluxes or Solvents, Components of the Colours; Reds, etc., from Gold, Carmine or Rose Colour, Purple, Reds, etc., from Iron, Blues, Yellows, Greens, Blacks, White, Silver for Burnishing, Gold for Burnishing, Printer's Oil, Lustres. PART III., TABLES OF THE CHARACTERISTICS OF CHEMICAL SUB- STANCES. Preliminary Remarks, Oxygen (Tables), Sulphur and its Compounds, Nitrogen ditto, Chlorine ditto, Bromine ditto, Iodine ditto, Fluorine ditto, Phosphorus ditto, Boron ditto, Carbon ditto, Hydrogen ditto, Observations, Ammonium and its Compounds (Tables), Thorium ditto, Zirconium ditto, Aluminium ditto, Yttrium ditto, Glucinum ditto, Magnesium ditto, Calcium ditto, Strontium ditto, Barium ditto, Lithium ditto, Sodium and its Compounds, Potassium ditto, Observations, Selenium and its Compounds (Tables), Arsenic ditto, Chromium ditto, Vanadium ditto, Molybdenum ditto, Tungsten ditto, Antimony ditto, Tellurium ditto, Tantalum ditto, Titanium ditto, Silicium ditto, Osmium ditto, Gold ditto, Iridium ditto, Rhodium ditto, Platinum ditto, Palladium ditto, Mercury ditto, Silver ditto, Copper ditto, Uranium ditto, Bismuth aud its Compounds, Tin ditto, Lead ditto, Cerium ditto, Cobalt ditto, Nickel ditto, Iron ditto, Cadmium ditto, Zinc ditto, Manganese ditto, Observations, Isomorphous Groups, Isomeric ditto, Metameric ditto, Polymeric ditto, Index. ENAMELS AND ENAMELLING. An Introduction to the Preparation and Application of all Kinds of Enamels for Technical and Artistic Purposes. For Enamel Makers, Workers in Gold and Silver, and Manufacturers of Objects of Art. By PAUL RANDAU. Translated from the German. With 16 Illustrations. Price ; Abroad, strictly net, post free. Contents. I., Introduction. II., Composition and Properties of Glass. III., Raw Materials for the Manufacture of Enamels. IV., Substances Added to Produce Opacity. V., Fluxes. VI., Pig- ments. VII., Decolorising Agents. VIII., Testing the Raw Materials with the Blow-pipe Flame. IX., Subsidiary Materials. X., Preparing the Materials for Enamel Making. XL, Mixing the Materials. XII., The Preparation of Technical Enamels : The Enamel Mass. XIII., Appliances for Smelting the Enamel Mass. XIV., Smelting the Charge. XV., Com- position of Enamel Masses. XVI., Composition of Masses for Ground Enamels. XVII., Composition of Cover Enamels. XVIII., Preparing- the Articles for Enamelling. XIX., Applying the Enamel. XX., Firing the Ground Enamel. XXL, Applying and Firing the Cover Enamel or Glaze. XXII., Repairing Defects in Enamelled Ware. XXIII., Enamelling Articles of Sheet Metal. XXIV., Decorating Enamelled Ware. XXV., Specialities in Enamelling. XXVI. , Dial-plate Enamelling. XXVIL, Enamels for Artistic Purposes: Re- cipes for Enamels of Various Colours. Index. Books on Textile Subjects. THE TECHNICAL TESTING OF YARNS AND TEXTILE FABRICS, with Reference to Official Specifications. Translated from the German of Dr. J. HERZFELD. With 69 Illustrations. Price 10s. 6d. ; France and Belgium, 13 frs. ; Colonies, 12s., post free. Contents. Yarn Testing. III., Determining the Yarn Number. IV., Testing the Length of Yarns. V., Examination of the External Appearance of Yarn. VI., Determining the Twist of Yarn and Twist. VII., Determination of Tensile Strength and Elasticity. -VIII., Estimating the Percentage of Fat in Yarn. IX., Determination, of Moisture (Conditioning). Appendix. 12 Press Opinions. " The author has endeavoured to collect and arrange in systematic form for the first time all the data relating to both physical and chemical tests as used throughout the whole of the textile industry, so that not only the commercial and textile chemist who has frequently to reply to questions on these matters, but also the practical manufacturer of textiles and his subordinates, whether in spinning, weaving, dyeing, and finishing, are catered for. . . . The book is protusely illustrated, and the subjects of these illustrations are clearly described." Textile Manufacturer. " This is probably the most exhaustive book published in English on the subject dealt with. . . . We have great confidence in recommending the purchase of this book by all manufacturers of textile goods of whatever kind, and are convinced that the concise and direct way in which it is written, which has been admirably conserved by the translator, renders it peculiarly adapted for the use of English readers." Textile Recorder. " A careful siudy of this book enables one to say with certainty that it is a standard work on the subject. Its importance is enhanced greatly by the probability that we have here, for the first time in our own language, in one volume, a full, accurate, and detailed account, by a prac- tical expert, of the best technical methods for the testing of textile materials, whether in the raw state or in the more or less finished product." Glasgow Herald. " It would be well if our English manufacturers would avail themselves of this important addition to the extensive list of German publications which, by the spread of technical infor- mation, contribute in no small degree to the success, and sometimes to the supremacy, of Germany in almost every branch of textile manufacture." Manchester Courier. DECORATIVE AND FANCY TEXTILE FABRICS. With Designs and Illustrations. By R. T. LORD. A Valuable Book for Manufacturers and Designers of Carpets, Damask, Dress and all Textile Fabrics. Price 7s. 6d. ; Other Countries, 9s., post free. Contents. Chapters I., A few Hints on Designing Ornamental Textile Fabrics. II., A few Hints on Designing Ornamental Textile Fabrics (continued). III., A few Hints on Designing Orna- mental Textile Fabrics (continued). IV., A few Hints on Designing Ornamental Textile fabrics (continued). V., Hints for Ruled-paper Draughtsmen. VI., The Jacquard Machine. VII., Brussels and Wilton Carpets. VIII., Tapestry Carpets. IX., Ingrain Carpets. X. Axminster Carpets. XI., Damask and Tapestry Fabrics. XII., Scarf Silks and Ribbons. XIII., Silk Handkerchiefs. XIV., Dress Fabrics. XV., Mantle Cloths. XVI., Figured Plush- XVII., Bed Quilts. XVIII. Calico Printing. Press Opinions. " The book is to be commanded as a model manual, appearing at an opportune time, since every day is making known a growing desire for development in British industrial art." Dundee A dvertiser. " Those engaged in the designing of dress, mantle tapestry, carpet and other ornamental textiles will find this volume a useful work of reference." Leeds Mercury. " The writer's avocation is that of a designer for the trade, and he therefore knows what he is writing about. . . . The work is well printed and abundantly illustrated, and for the author's share of the work we have nothing but commendation. It is a work which the student designer will find thoroughly useful." Textile Mercury. " Designers especially, who desire to make progress in their calling, will do well to take the hints thrown out in the first four chapters on ' Designing Ornamental Textile Fabrics '." Nottingham Daily Guardian. " The book can be strongly recommended to students and practical men." Textile Colorist. POWER=LOOM WEAVING AND YARN NUMBERING, according to various Systems, with Conversion Tables. An Auxiliary and Text-book for Pupils of Weaving Schools, as well as for self- instruction and for general use, by those engaged in the Weaving Industry. Translated from the German of ANTHON GRUNER. With Coloured Diagrams. Price 7s. 6d. ; Abroad, 9s., strictly net, post free. Contents. I., Power=Loom Weaving in General. Various Systems of Looms. II., Mounting and Starting the Power=Loom. English Looms. Tappet or Treadle Looms. Dobbies. III., General Remarks on the Numbering, Reeling and Packing of Yarn. Appendix. Useful Hints. Calculating Warps. Welt Calculations. Calculations of Cost Price in Hanks 13 Press Opinions. " This work brings before weavers who are actually engaged in the various branches of fabrics, as well as the technical student, the different parts of the general run of power-looms in such a manner that the parts of the loom and their bearing to each other can be readily under- stood. . . . The work should prove of much value, as it is in every sense practical, and is put before the reader in such a clear manner that it can be easily understood." Textile Industries. " The work has been clearly translated from the German and published with suitable illustrations. . . . The author has dealt very practically with the subject." Bradford Daily Telegraph. " The book, which contains a number of useful coloured diagrams, should prove invaluable to the student, and its handy form will enable it to become a companion more than some cum- brous work." Cotton Factory Times. " The book has been prepared with great care, and is most usefully illustrated. It is a capital text-book for use in the weaving schools or for self-instruction, while all engaged in the weaving industry will find its suggestions helpful." Northern Daily Telegraph. THE COLOUR PRINTING OF CARPET YARNS. A Useful Manual for Colour-Chemists and Textile Printers, by DAVID PATERSON, F.C.S. 132 pp. Illustrated. Price 7s. 6d. ; Abroad, 9s., strictly net, post free. Contents. Chapters I., Structure and Constitution of Wool Fibre. II., Yarn Scouring. III., Scouring Materials. IV., Water for Scouring. V., Bleaching Carpet Yarns. VI., Colour Making for Yarn Printing. VII., Colour Printing Pastes. VIII., Colour Recipes for Yarn Printing. IX., Science of Colour Mixing. X., Matching of Colours. XL, "Hank" Printing. XII., Printing Tapestry Carpet Yarns. XIII., Yarn Printing. XIV., Steaming Printed Yarns. XV., Washing of Steamed Yarns. XVI., Aniline Colours suitable for Yarn Printing. XVII., Glossary of Dyes and Dye-wares used in Wood Yarn Printing. Appendix. Press Opinions. " The subject is very exhaustively treated in all its branches. . . . The work, which is very well illustrated with designs, 'machines, and wool fibres, will be a useful addition to our textile literature." Northern Whig.' " The book is worthy the attention of the trade." Worcester Herald. " An eminent expert himself, the author has evidently strained every effort in order to make his work the standard guide of its class" Leicester Post. " It gives an account of its subject which is both valuable and instructive in itself, and likely to be all the more welcome because books dealing with textile fabrics usually have little or nothing to say about this way of decorating them." Scotsman. " The work shows a thorough grasp of the leading characteristics as well as the minutias of the industry, and gives a lucid description of its chief departments. ... As a text-book in technical schools where this branch of industrial education is taught the book is valuable, or it may be perused with pleasure as well as profit by any one having an interest in textile industries." Dundee Courier. "The treatise is arranged with great care, and follows the processes described in a manner at once clear and convincing." Glasgow Record. Books on Plumbing. EXTERNAL PLUMBING WORK. A Treatise on Lead Work for Roofs. By JOHN W. HART, R.P.C. Price 7s. 6d., post free ; Other Countries, 8s. List of Chapters. Chapters I., Cast Sheet Lead. II., Milled Sheet Lead. III., Roof Cesspools. IV., Socket Pipes. V., Drips. VI., Gutters. VII., Gutters (continued). VIII., Breaks. IX., Circular Breaks. X., Flats. XI., Flats (continued). XII., Rolls on Flats. XIII., Roll Ends. XIV., Roll Intersections. XV., Seam Rolls. XVI., Seam Rolls (continued). XVII., Tack Fixings. XVIII., Step Flashings. XIX., Step Flashings (continued). XX., Secret Gutters. XXI., Soakers. XXII., Hip and Valley Soakers. XXIII., Dormer Windows. XXIV., Dormer Windows (continued). XXV., Dormer Tops. XXVI., Internal Dormers. XXVII., Skylights. XXVIII., Hips and Ridging. XXIX., Hips and Ridging (continued). XXX.. Fixings for Hips and Ridging. XXXI., Ornamental Ridging. XXXII., Ornamental Curb Rolls. XXXIII., Curb Rolls. XXXIV., Cornices. XXXV., Towers and Finials. XXXVI., Towers and Finials (continued). XXXVII. .Towers and Finials (continued). XXXVIII. .Domes. XXXIX. .Domes (continued). XL., Ornamental Lead Work. XLI., Rain Water Heads. XLII., Rain Water Heads (continued). XLIII., Rain Water Heads (continued). 14 Press Opinions. " The publication of this book will do much to stimulate attention and study to external plumbing work, for it is a book which we can heartily recommend to every plumber, both old and young, who desires to make himself proficient in the several branches of his trade. We can heartily recommend the book to plumbers and architects." Sanitary Record. " This is an eminently practical and well-illustrated volume on the management of external lead work." Birmingham Daily Post. ' It is thoroughly practical, containing many valuable hints, and cannot fail to be of great benefit to those who have not had large experience." Sanitary Journal. " With Mr. Hart's treatise in his hands the young plumber need not be afraid of tackling outside work. He would do well' to study its pages at leisure, so that he may be ready for it when called upon." Ironmongery. " Works on sanitary plumbing are by no means rare, but treatises dealing with external plumbing work are sufficiently scarce to ensure for Mr. Hart's new publication a hearty recep- tion." The Ironmonger. HINTS TO PLUMBERS ON JOINT WIPING, PIPE BENDING AND LEAD BURNING. Second Edition, Revised and Corrected. By JOHN W. HART, R.P.C. Over 300 pages, Illus- trated. Price 7s. 6d. ; Other Countries, 8s., post free. List of Chapters. x., Introduction. Chapters I., Pipe Bending. II., Pipe Bending (continued). III., Pipe Bending (continued). IV., Square Pipe Bendings. V., Half-circular Elbows. VI., Curved Bends on Square Pipe. VII., Bossed Bends. VIII., Curved Plinth Bends. IX., Rain-water Shoes on Square Pipe. X., Curved and Angle Bends. XL, Square Pipe Fixings. XII., Joint- wiping. XIII., Substitutes for Wiped Joints. XIV., Preparing Wiped Joints. XV., Joint Fixings. XVI., Plumbing Irons. XVII., Joint Fixings. XVIII., Use of "'Touch " in Solder- ing. XIX., Underhand Joints. XX., Blown and Copper Bit Joints. XXL, Branch Joints. XXIL, Branch Joints (continued). XXIII. , Block Joints. XXIV., Block Joints (continued). XXV., Block Fixings. XXVI., Astragal Joints Pipe Fixings. XXVII., Large Branch Joints. XXVIII., Large Underhand Joints. XXIX., Solders. XXX., Autogenous Soldering or Lead Burning. Press Opinions. " Rich in useful diagrams as well as in hints." Liverpool Mercuiy. " A well got-up and well-done practical book. It is freely illustrated and is a reliable help in respect of some of the most awkward work the young plumber has to perform." The Ironmonger. " The papers are eminently practical, and go much further into the mysteries they describe than the title ' Hints ' properly suggests." Scotsman. " The articles are apparently written by a thoroughly practical man. As a practical guide the book will doubtless be of much service." Glasgow Herald. " So far as the practical hints in this work are concerned, it will be useful to apprentices and students in technical schools, as it deals mainly with the most important or difficult branches of the plumber's craft, viz., joint wiping, pipe bending and lead burning. . . . ' Hints ' are the most useful things to an apprentice, and there are many in this work which are not to be found in some of the text-books." English Mechanic. " I is a book for the intelligent operative first of all, not a mere manual of instruction for the beginner, nor yet a scientific treatise on the whole art of sanitary plumbing. The special subject with which it deals is joint-making, the most important branch of the operative's work, and into this topic the author goes with a thoroughness that is full of suggestion to even the most experienced workman. There is no one who has to do with plumbing but could read the book with profit." Ironmongery. 15 WORKS IN PREPARATION A HISTORY OF DECORATIVE ART. For Designers, Decorators and Workmen. [Nearly Ready. HOUSE PAINTING AND DECORATING. A Handbook for Painters and Decorators. [Nearly Ready. THE PRINCIPLES AND PRACTICE OF DIPPING, BUR- NISHING AND BRONZING BRASS WORK. [Nearly Ready. THE SCIENCE OF COLOUR MIXING. A Manual in- tended for the use of Dyers, Calico Printers, Colour Chemists and Students. By DAVID PATERSON, F.C.S. WAXES. AGRICULTURAL CHEMISTRY. THE MANUFACTURE OF BRUSHES OF EVERY DES- CRIPTION. THE ART AND PRACTICE OF BLEACHING. [In the Press. THE MANUFACTURE OF LEATHER. Translated from the French of M. VILLON. [In the Press. A TREATISE ON THE CERAMIC INDUSTRY. By EMILLE BOURRY. MINING SAFETY APPLIANCES. THE MANUFACTURE OF LAKE PIGMENTS. By T. H. JENNISON, F.S.S., etc. [In the Press. THE RISKS AND DANGERS OF VARIOUS OCCUPA- TIONS AND THEIR PREVENTIONS. By Dr. L. A. PARRY. COLOUR MATCHING ON TEXTILES. A Manual intended for the use of Students of Colour Chemistry, Dyeing and Textile Printing. By DAVID PATERSON, F.C.S. 16 TERRA=COTTA, BRICKS AND POTTERY FOR BUILDING PURPOSES. TECHNOLOGY OF PETROLEUM. By NEUBURGER and NOALHAT. HOT WATER SUPPLY. [In the Press. THE CULTURE OF HOPS. [In the Press. THE RONTJEN RAYS IN MEDICAL PRACTICE. CONTINENTAL PATENTS FOR GAS APPARATUS. SULPHATES OF IRON AND ALUMINIUM AND ALUM INDUSTRY. By L. GESCHWIND. 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