[ 175 J 148 



guard against it, and to remove it. Previously to being boiled, the 

 water sliould be permitted to settle, and the pan must be carefully 

 wiped; if necessary, the basin should be covered while the water is 

 heating. If sand be perceived in the vvatei-, it must be poured ojft', and 

 the sand washed out, for a single grain may cause the fibre to break. 



When the cocoons are lirst put in the water, if the silk rises tliick 

 upon the brush, or conies in lumps, it is a sign that the water is too 

 hot; if the thread cannot be caught, the Avater is too cold. When the 

 cocoons are in play, if they rise often to the holes in the iron plate, 

 the water is too hot; if the cocoons do not follow the threads, it is too 

 cold. 



Keep an equal number of cocoons working at each end of the basin, 

 in order to preserve the thread of silk of an equal size. When there 

 are fewer on one side than the other, the silk becomes smaller at that 

 side, and the thread will break. Therefore, throw in the cocoons one. 

 by one, and never more than two at a time. 



It will be seen, by observing the position of the thread upon the 

 reel, that the difl'erent layers do not lie parallel to, nor upon, but cross 

 one another. This is owing to the mechanism of the apparatus, and 

 is particularly contrived to effect this object, which is essential to the 

 perfection of the process, and one to which the acknowledged superi- 

 ority of the Italian silk is to be ascribed. It is effected by the see-saw 

 or horizontal motion of the traversing bar, and is produced by the 

 different number of the teeth in the pinion of the axle, and in the 

 wheels at the ends of the shaft E, and in the pinions on the top of the- 

 post K, which catch and work upon one another. W^ithout this cross- 

 ing, the threads, from their gummy nature,- would inevitably adhere, 

 and render the subsequent windings and twistings of the silk very 

 difficult; causing the threads frequently to break, and, when joined, 

 to form knots, which, in weaving, cannot pass through the reeds, and 

 hence injure the beauty of tjie stuffs. But the mechanism mentioned 

 of the traversing bar, prevents the threads lying over each other upon 

 the reel, until after it has made many revolutions. Borgnis* says, that 

 a thread cannot be found to occupy the same place it had at the com- 

 mencement of the reeling, until after eight hundred and seventy-five 

 turns of the reel. During this time, the exposure of the threads to the 

 air, causes the first layer to dry completely, and hence no adhesion be- 

 tween them can take place. The double irregularity of movement 

 which takes place between the traversing bar, and the axle which 

 moves it, forms also an internal motion, the effect of which is to imi- 

 tate, in the unravelling of the cocoon, the same method employed by 

 the silk caterpillar in forming it: for it is a fact, as before said, that 

 the silk fibres of the cocoon are spun on it in zig-zags, like those 

 formed by the silk reel, and, consequently, the operation of the reel is 

 an imitation of nature, of which the industry of the caterpillar,- in- 

 structed by her, is the prototype. 



W^ith tile view of increasing the facility of drying the threads, the 

 law of Piedmont requires the distance between the posts or supports 



* Traite de Mechanique, applique aux Aits, vol. 7. 



