When full grown the silkworm commences spinning its web in some convenient spot; and as it does not change the position of the hinder portion of its body much, but conti nues drawing its thread from various points and attaching it to others, it follows that after a time its body becomes in a great measure inclosed by the thread. The work is then continued from one thread to another, the silkworm moving its head and spinning in a zigzag way, bending the fore part of the body back to spin in all directions within reach, and shifting the body only, to cover with silk the part which was beneath it. As the silk worm spins its web by thus bending the fore part of the body back, and moves the hinder part of the body in such a way only as to en able it to reach the farther back with the fore part, it follows that it incloses itself in a cocoon much shorter than its own body ; for soon after the beginning the whole is con tinued with the body in a bent position. From the foregoing account it appears that with the most simple instinctive principles all the ends necessary are gained. If the silkworm were gifted with a desire for shifting its position much at the beginning of the work it could never inclose itself in a cocoon ; but by its mode of proceeding, as above explained, it inclose:, itself in a cocoon which only consumes as much silk as is necessary to hold the chrysa lis. During the time of spinning the cocoon, the silkworm decreases in length very consi derably, and after it is completed it is not half its original length; at this time it becomes quite torpid, soon changes its skin, and appears in the form of a chrysalis. The time required to complete the cocoon is about fivo days. In the chrysalis state the animal remains from a fortnight to three weeks; it then bursts its case, and comes forth in the imago state, the moth having previously dis solved a portion of the cocoon by means of a fluid which it ejects.
Silk is obtained also from the spider ; not from the cobweb, but the silky thread which the female spider spins round her eggs. The silken fibres of the piuna form a strong and beautiful fabric ; and some species of moths form cocoons which may be spun for curiosity, but not with a view to commercial profit.
Reeling from the cocoons is only performed in countries where the silk is produced. Silk reaches the weaver in three different states, in which it is called single, tram, and organzine, %lie Preparation of which is the business of the throwster. In plain silk-weaving the pro cess is much the same as in weaving woollen or linen ; but the weaver is assisted by a machine for the even distribution of the which frequently consists of eight thousand separate threads in a breadth of twenty inches. The Jacquard-Loom has been the means of facilitating and cheapening the production Of fancy or figured silks to an extraordinary ex tent. Patterns which required the greatest degree of skill and the most painful labour are produced by this machine by weavers of ordinary skill, and with but little more labour than that required in weaving plain silks.
[Jacounnn]. The power-loom has been only partially employed in the silk manufacture; and excepting for the commonest goods, it does not possess any great advantage over the handloom, as the delicacy of the mater vial to be worked, and the attention which must be given to the process of the weft, frequently render it necessary to stop the machine.
The general processes of the silk manufac ture have been treated at some length under RIBAND j and some other articles of silk manufacture are noticed under their proper names. Brocade and damask, the most sump tuous articles of silk manufacture a century ago, are now comparatively unknown. Per sian, sarsnet, gros. de-Naples, du capes, satin, and levantines, are the names given to plain silks, which vary from one another only in texture, quality, or softness. Satin derives its lustre from the great proportion of the threads of the warp being left visible, and the piece being afterwards passed over heated cylinders. Other varieties of silk goods arc produced by mechanical arrangements of the loom, such as using different shuttles with threads of various substances, &c. The pile which constitutes the peculiarity of velvet is produced by the insertion of short pieces of silk thread, which cover the surface so entirely as to conceal the interlacings of the warp and woof. The process of weaving velvet is slow, and it is paid for at five times the rate of plain silks. There are several sorts of goods in which silk is employed with woollen mate rials, as poplins and bombazines.
A few of the circumstances which have marked the progress of the silk manufacture in England are noticed under SerrALFIELDs. Ten or twelve years ago, one half of the silk manufactories were in Cheshire, next to which stood Lancashire, Derbyshire, and Stafford shire; but Lancashire has recently advanced more than the other counties in this de partment of industry. The following were the statistics of silk factories in the year 1850: Factories in England 272 Spindles 1,188,008 Power looms 6,002 Steam and water 8,571 horse power.
power Male operatives 12,513 Female operatives 20,100 the 272 silk factories, 07 were in Cheshire (chiefly at Macclesfield and Congleton). There were only five silk factories in Scotland, employing 811 persons. There was no silk factory either in Ireland or in Wales.
The silk imported in 1850 amounted to :— Raw 4,912,417 lbs.
Waste and husks 14,600 cwts.
Thrown 469,526 lbs.
The manufactured silk goods imported in 1850, including broad silk, satin, ribbons, gauze, crape, velvet, and plush, amounted in weight to 826,650 lbs.; together with 715,730 pieces of Bandanna and other silk handker chiefs. Our exports were 260,085 lbs., toge ther with 410,473 pieces of silk handkerchiefs —mostly to the colonies.