SILK. 181 



is effected under the hook or cash, and therefore requires no pause to pass 

 it through the hole, unless all five break together, when she must pass 

 a new thread up the hole. The cocoons which are attached float 

 promiscuously about with the others, or bob about, like fishes catching 

 the rain, just under the hooks. The skeins are about 3 or 4 inches 

 broad, and the same distance from each other. 



"The way in which the silk is distributed over this breadth, instead 

 of becoming all ravelled in a narrow rope, is ingenious in the extreme, 

 and I will endeavour to describe it. At the other (that is, not the 

 crank) end of the axle is a prolongation about 4 inches beyond the 

 spokes. This prolongation is a mere shade thicker than the rest of the 

 axle, and is, moreover, roughened. Over this runs a wooden wheel or 

 block about 6 inches in diameter and 3 inches in tyre thickness, the axis 

 of which is at right angles to the axle of the great wheel. The rough- 

 ness of the axle prolongation causes this block wheel both to revolve and 

 to bob slowly and gently, the first in a horizontal and the second in a 

 perpendicular direction, and is, in fact, a rough application of the 

 slanting-cog principle. The axis of the block wheel in the shape of a 

 stick runs up and supports a crutch-like top, which is often carved in the 

 fanciful form of a canary. The canary thus goes whizzing around, and 

 both over and to either his head or tail a lath is fastened by a nail, the 

 other end of which runs to and fro over a small bar running parallel to 

 the long side of the large frame. The bird is really nothing more than 

 a small crank. At intervals of 4 inches apart in the lath are affixed tiny 

 crutches about 4 inches high, having tops or hooks not more than an 

 inch across. Through these tops the thread is made to run before it is 

 attached to the large wheel ; and, as the tops move 2 or 3 inches from 

 side to side in a direction across the felloe of the wheel and parallel with 

 its axle, of course the thread never remains in a straight line, but is 

 wound slightly diagonally." 



Fig. 116 shows a number of skeins of the highest qualities of silk, 

 and also some of the lowest qualities that are used in commerce. For 

 these specimens I am indebted to the late Mr. Alderman John Thorpe. 



According to Mr. C. F. Cobb, silk may be distinguished from 

 vegetable fibres by burning the fibres, when it emits a smell of burnt 

 horn. Wool gives a similar odour. When submitted to the action of 

 nitric acid, the fibre is turned yellow. Silk is dissolved by strong alkalies. 

 Dilute alkalies affect it, but without solution ; .ammonia has no action on 

 the silk fibre. Schweitzer's solution dissolves the silk fibre just as it does 

 cotton. Silk, like wool, has an affinity for tinctorial dyes. A solution 

 of zinc chloride of 1 '7 specific gravity dissolves silk, but has no action on 

 wool. The silk is reprecipitated on adding water. 



