ON THE UNION OF FLEXIBLE FIBRES. 143 



depresses the threads in succession by means of treadles, moved by the 

 feet, in an order which is different, according to the different nature of the 

 intended work ; the cross thread or woof, being thrown between them at 

 each alternation, by means of a shuttle, and forced into its place by a 

 batten or comb made of wire or reeds, while the piece, in proportion as it 

 is completed, is rolled upon a second beam opposite to the first. 



Crape is composed of threads which are so strongly twisted, as to have 

 a disposition to curl, and in weaving it, moisture is sometimes employed, 

 in order to obviate this tendency during the process. Woollen cloth, when 

 woven, is rendered stronger and more compact by means of the fulling 

 mill, in which it is beaten by heavy hammers of wood, at the same time 

 that fullers' earth, or alcaline substances of animal origin, are applied in 

 order to cleanse it. In this operation both its length and breadth are 

 diminished, and it is reduced to a texture approaching to that of felt. 

 The reason of the contraction is probably this, that all the fibres are bent 

 by the operation of the hammer, but not all equally, and those which have 

 been the most bent are prevented by their adhesion to the neighbouring 

 fibres from returning to their original length. After fulling, the cloth is 

 roughened by means of teasels, which are cultivated for the purpose ; and 

 the most projecting fibres are cut away by the operation of shearing. 



The lateral adhesion of fibres of various kinds gives strength also to 

 felted substances, assisted, as some assert, by minute barbs, with which 

 the fibres of furs are said to be furnished. The whole strength is, how- 

 ever, much inferior to that of cloth ; partly because the fibres are in 

 general much shorter, and partly because their arrangement is less accu- 

 rately adjusted.* 



The materials commonly used for felting are the furs of rabbits and 

 beavers, mixed with each other, and with sheep's wool, in various pro- 

 portions, according to the quality required. A very fine fur has lately 

 been discovered on the skin of a species of seal, mixed with its hair, and it 

 has been employed not only for felting, but also for spinning and weaving 

 into a cloth resembling the shawls of the East Indies. The fur of the 

 rabbit is also mixed with a coarser hair, which is separated from it, by 

 being first pulled off from the skins, with a sharper knife. The materials 

 to be felted are intimately mixed by the operation of bowing, which de- 

 pends on the vibrations of an elastic string; the rapid alternations of 

 its motion being peculiarly well adapted to remove all irregular knots and 

 adhesions among the fibres, and to dispose them in a very light and 

 uniform arrangement. This texture, when pressed under cloths and 

 leather, readily unites into a mass of some firmness ; this mass is dipped 

 into a liquor containing a little sulfuric acid, and when intended for a hat, 

 is moulded into a large conical figure, which is reduced in its dimensions 

 by working it with the hands, and is formed into a flat surface with 

 several concentric folds, which are still more compacted in order to make 

 the brim and the circular part of the crown, and forced on a block which 

 selves as a mould for the cylindrical part. The black dye is composed of 

 * On Hatmaking, see Nich. Jour. 4to, i. 67 ; iii. 22, 73. 



