MECHANICS AND USEFUL ARTS. 63 



and, until within a comparatively recent period, the ounce of metal could not 

 be drawn into more than nine hundred or one thousand yards. 



The author said that one of the firm to which he was indebted was, he 

 believed, the first to suggest the use of a jewelled die. They experienced 

 many difficulties at first ; but all were overcome, and a perforated ruby, set 

 in a metallic frame, answered admirably, and enabled the drawer to produce 

 from one ounce of metal, a wire a mile and a quarter long. In connection 

 with this discovery, it is somewhat singular that there are not more than 



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three men in London capable of perforating and setting these ruby dies 

 properly ; and one man, who works probably not more than three hours a 

 day on the average, has received from one wire-drawing firm as much as 

 500 or 600 in a single year, while they only pay from, four to five shillings 

 for each die. 



So great is the tenacity of even the finest size, that a piece of wire twelve 

 inches long will bear twelve ounces in weight. It is now ready to be flat- 

 tened preparatory to spinning round the silk. The flattening machine con- 

 sists of only two rollers for it to pass between, the one being about ten, and 

 the other about four inches in diameter, and about two inches wide, slightly 

 convex on the face. To impress a substance as fine as a hair, and flatten it 

 to twice or treble its original width, requires the nicest possible adaptation of 

 parts. A single pair of rollers costs 120. The metal is of the rarest 

 quality of steel, and the polish higher than the finest glass. At one time 

 these rollers were made in Sheffield, but now they are manufactured in 

 Rhenish Prussia. 



The wire so flattened is now wound on small bobbins, which are placed on 

 the edge of circular rings, attached to a bar over a spinning frame. On the 

 front of the frame, twelve inches from the floor, are bobbins of silk, the 

 threads of which ascend and pass through the centre of the ring to which 

 the reel with wire is fixed. The whole is set in motion, and while the thread 

 is being twisted, the ring with the wire revolves round the thread in the op- 

 posite direction, and thirty or forty threads are plated at once. In its new 

 form, though only gold is seen, probably nine tenths of its bulk is silk, while 

 of the remaining one tenth, only one-fiftieth part is gold, so by labor and 

 ingenuity we are put in possession of a gold thread, of which only one part 

 in five hundred is gold. 



Let us glance only for a moment at the labor required to reduce the ingot 

 of silver, weighing 420 ounces, to the finished wire, weighing 360 ounces, 

 sixty ounces having been cut off not destroyed in the several processes 

 of pointing, planing, and occasional accidental waste. Allowing ten hours 

 to the day, it would take one man seventy days or ten weeks to reduce by 

 his labor the ingot of silver, weighing 420 ounces, to its finest size. But no 

 one man is equal to the entire duty. The early processes demand the exer- 

 cise of Titanic powers, while the later processes demand the lightest touch 

 of almost fairy fingers. 



There may be some errors in this estimate, arising from imperfect inform- 

 ation, but the author believed it would be found sufficiently accurate to en- 

 able one to estimate the labor required to make four hundred ounces of 



