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in the threads. After the cocoons by reeling have been 

 converted into raw silk, that silk, before it can be used 

 in the manufactory of fine stuffs, must undergo the oper- 

 ation of throwsting, that is to say twisting, which is done 

 by means of a machine called a throwing or throwsting 

 mill, and the mechanics who perform that work are called 

 silk throwsters. There are several of them already in the 

 United States, chiefly from England, but they have as yet 

 been mostly employed in throwsting foreign silk, imported 

 chiefly from China.* The operation of throwsting is the 

 test of the good or bad reeling of raw silk. If it be entan- 

 gled, or not sufficiently freed f*om its gum, the threads 

 break in the preparatory operation of winding, and 

 that occasions much loss. If the threads are not 

 equal, that is to say, if there is not in each thread 

 as nearly as possible the same number of fibres, as the 

 twisting is done by machinery which works by an equal 

 regular motion, the force which will only twist the strong 

 parts of the thread will break the weak ones, and that 

 with the loss by winding, produces what is called waste. 

 In proportion to the greater or less quantity of waste that 

 is found in raw silk is the price or value in foreign mar- 

 kets. 



Mr Du Ponceau has communicated to me a letter 

 which he has received from an eminent silk merchant 

 in Paris, in which he tells him that the best French raw 

 silks of 15 to 20 fibres, lose only by waste 1 to 2 per 

 cent; those of Asiatic Turkey, from 6 to 8 ; those of 

 Calabria, 8 to 12; those of Valencia in Spain, 6 to 8; 



* I have had three of them in my employ. 



