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XV. A Method of drawing extremely fine Wires, By William 

 Hyde Wollaston, M. D. Sec. R. S. 



Read February 18, 1813. 



It is recorded by Musschenbroek, that an artist of Augsburg 

 drew a wire of gold so slender, that live hundred feet of it 

 weighed only one grain ; but the method by which this was 

 effected is not mentioned, and indeed it has been doubted, 

 whether it could really have been done. I shall however 

 shew, that a wire of gold may, without much difficulty, be 

 obtained finer than that spoken of by Musschenbroek, and 

 that wires of platina may be drawn much more slender, with 

 the utmost facility. 



Those who draw silver wire in large quantities for lace and 

 embroidery, sometimes begin with a rod that is about three 

 inches in diameter, and ultimately obtain wires that are as 

 small as xio of an inch in thickness. If in any stage of this 

 process a rod of silver wire be taken, and a hole be drilled 

 through it longitudinally, having its diameter one-tenth part 

 of that of the rod, and if a wire of pure gold be inserted, so 

 as to fill the hole, it is evident that by continuing to draw the 

 rod, the gold within it will be reduced in diameter exactly in 

 the same proportion as the silver; so that if both be thus 

 drawn out together till the diameter of the silver is g^ of an 

 inch, then that of the gold will be only -^-^^^^ ; and of such 

 wire five hundred and fifty feet would be requisite to weigh 

 one grain. 



