CHAMBERS'S INFORMATION FOR THE PEOPLE. 



may be generally stated to be like that of making 

 rope, where the combined strands are twisted in 

 an opposite direction to that given to the separate 

 threads, and this is accomplished by giving a 

 reverse motion to the machinery ; whereas singles 

 and trams are twisted only in one direction, simi- 

 larly to twine, or to the individual strands of 

 which the larger rope is made. Silk thread 

 intended for organzine is in the first process 

 twisted in a left-hand direction. 



The preparation of raw silk, that is, silk in the 

 hanks as imported, is carried on as an especial 

 trade that of the silk-throwster in large factories, 

 with expensive and complicated machinery suited 

 to the different processes. 



The first to be noticed is that of winding. In 

 this operation, the hanks are stretched on a light 

 hexagonal reel, termed a swift. The silk is led 

 from these to a series of bobbins placed hori- 

 zontally in a frame, some distance above, and in 

 advance of the reels, one bobbin being allotted to 

 each reel. The threads of silk are wound upon 

 the bobbins, uniformly over the surfaces, by being 

 passed through eyes which are placed on a bar 

 having a lateral movement to and fro. The silk 

 thread thus wound upon a series of bobbins is 

 next cleaned that is, each thread is made to pass 

 through an aperture ; but before passing through 

 the hole, the silk is cleaned from dust by coming 

 in contact with a brush. 



The next operation is that of throwing or twist- 

 ing. The silk bobbins from the previous machine 

 are placed horizontally in a frame in one or two 

 rows, one above the other ; at a little distance 

 below these horizontal bobbins are placed a series 

 of vertical ones ; these, however, have no motion 

 on their axes, like the horizontal ones, but are 

 stationary. A spindle passes through a central 

 aperture on each of the bobbins, and is made to 

 revolve quickly. At the upper end of the spindle, 

 a small flyer (see Cotton) is fixed. The silk is 

 passed from the horizontal bobbin through the 

 eye of the flyer, and by the rapid rotation of the 

 latter round the vertical bobbin, it is wound upon 

 its surface, receiving at the same time a twist. 

 The amount of twist given to the thread is 

 dependent upon the difference of speed between 

 the flyer and the horizontal bobbin which gives 

 out the silk. 



In the manufacture of tram, sewing-silk, and 

 organzine, the next process after spinning is that 

 of doubling. The bobbins, equal in number to 

 the threads to be united, are set in a frame, the 

 loose ends of the silk of the bobbins are collected, 

 and passed through a loop, and finally wound 

 round a horizontal reel. This is placed in the 

 throwing-machine, and the ends carried through 

 the eye of a flyer, which, by its rapid rotation 

 round a bobbin, winds it upon its surface, giving 

 it at the same time the desired twist. A number 

 of bobbins and flyers are arranged in one machine, 

 and an apparatus attached, by which, when a 

 thread breaks, the flyer with which it is connected 

 is stopped. 



Waste silk, which was, until some time early in 

 the present century, thought to be valueless, has 

 now become an important material, for it is now 

 willowed, or torn out of its entangled state, and 

 combed and span like flax, then spun into yarn, 

 and woven into the various fabrics known under 

 the general name of spun-silk. 



378 



The statistics of silk are very interesting. A 

 cocoon of the largest size will not yield more than 

 5 grains oiraiv silk, and about 23 of waste. It takes, 

 therefore, at a fair calculation, 1400 silkworms to 

 produce one pound of raw silk. The imports of 

 raw silk into Great Britain in 1866-1870 were 

 6,307,575 Ibs. or the produce of 8,830,605,000 

 silkworms. Besides waste silk to the extent of 

 3,512,320 Ibs. there were also imported 283,723 

 Ibs. of silk prepared as singles, tram, or organ- 

 zine. The total value of these quantities was 

 ,9,297,249, in addition to which manufactured 

 silk goods to the value of ^15,244,816 were im- 

 ported. The imports of raw silk for the three 

 years 1879-81 amounted to 10,464,951 Ibs., value 

 .8,981,702 ; while the manufactured goods were 

 valued at ^37,155,203. These figures for the 

 British trade should at least be multiplied by five, 

 to give the consumption of the whole world. 



WOOL. 



Wool, according to the definition given by Pro- 

 fessor Owen, ' is a peculiar modification of hair, 

 characterised by fine transverse or oblique lines 

 from 2000 to 4000 in the extent of an inch, indica- 

 tive of a minutely imbricated scaly surface when 

 viewed under the microscope, on which, and on 

 its curved or twisted form, depends its remarkable 

 felting property, and its consequent value in manu- 

 factures.' This will be seen in figs. 19 and 20, in 



Fig. 19- 



Fig. 20. 



which the wool is slightly magnified, to shew the 

 curled character. In fig. 20, two varieties are 

 shewn in section (a, c) and complete (b, d\ giving 

 the scaly characters. Wool, although principally 

 derived from the sheep in its many varieties, is 

 obtainable also from the goat and other animals. 

 The Tibet goat furnishes the finest of all wool ; 

 the merino sheep the next best. 



Wool, as used in our manufactures, is divided 

 into two sorts the long, or combing, and the 

 short, or carding wool. These, again, give rise 

 to the two grand divisions of the trade the 

 woollen, or the short-wool, and the worsted, or 

 long-wool departments. It is our duty to explain 

 briefly the various processes gone through in these, 

 taking the woollen as first in order. 



The wool of the sheep is removed from the 

 animal whilst alive, or from the skins after death ; 

 in either case it is found that there are several 

 1 different qualities, dependent chiefly on the length 

 of staple in each fleece. The -wool-stapler there- 

 fore takes it in hand, and, with great skill and 

 rapidity, separates one from the other into three 



