1^6 LECTURE XVI. 



wire or reeds, while the piece, in proportion as it is completed, is rolled up- 

 on a second beam, opposite to the first. 



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

 position 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 pro- 

 . bably 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, however, much inferior 

 to that of cloth ; partly because the fibres are in general nmch shorter, and 

 partly because their arrangement is less accurately 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 proportions, 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 opera- 

 tion of bowing, which depends 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 



