MECHANICS AND USEFUL ARTS. G5 



THE AMERICAN MANUFACTURE OF WATCH MOVEMENTS. 



A correspondent of the New York Times furnishes the following interest- 

 ing description of the works of the American Watch Company, at "VValtham, 

 Mass., in which, for the first time, the adaptation of machinery to the con- 

 struction of uniformly perfect watch movements, in their minutest and most 

 delicate details, has been successfully attempted. 



The better to understand the magnitude of the interests affected by this 

 enterprise, it should be remembered that the value of watches and watch 

 movements imported into the United States is about $5,000,000 per annum, 

 exclusive of many more which evade the Custom-house. It is estimated 

 that an equal sum is expended in this country alone in repairing defective 

 watches, and in vain attempts to coax them to run regularly. European 

 watches are made chiefly by hand. The rough parts of the movement are 

 collected usually from several distinct work-shops, all meeting at last upon 

 the bench of the finisher, perhaps in a distant city or some foreign country, 

 where the mechanism is fitted by measui'ement, and put in motion. Neces- 

 sarily very much must depend upon the accuracy of eye and steadiness of 

 hand of the workman; for the slightest deviation in size, length, or form of 

 any part of the intricate mechanism, must impair its value, if not render it 

 utterly useless. The variation of the ten thousandth part of an inch in the 

 size of a socket, or the measurements to determine its proper position, may 

 make all the difference between a perfect time-keeper and one which shall be 

 little else than a source of vexation and expense. 



In "jewelling," especially, is the highest accuracy of human workmanship 

 required. Jewelling, in watch-making, is the setting of precious stones 

 usually rubies, sapphires or chrysolites in positions subjected to friction, 

 in order to avoid the least change of form or size by long wear. Thus holes 

 to receive metal pinions must be made in substances inferior only to the 

 diamond in hardness ; and in planing, turning, and drilling the jewels, micro- 

 scopic exactness is indispensable ; for the pinions must move in their holes 

 with perfect ease, and yet without spare room to admit the minutest division 

 of a hair. The mode of piercing jewels, discovered in the year 1700 by M. 

 Facio, of Geneva, was for a long time a distinct art of itself. "With this 

 understanding of the delicate mechanical conditions requisite to a true time- 

 keeper, the reader will no longer wonder that there are so few perfect 

 watches, or that none but the best works of the best European finishers 

 heretofore, have approached perfection, nor that there is such absence of 

 correspondence in the practical working of watch movements, which to the 

 eye appear to be precisely alike. 



By the employment of ingenious machinery for the construction of each 

 and every part of the movement, the American "Watch Company have over- 

 come all the difficulties inseparable from the manufacture by hand. Each 

 of these machines has its peculiar office to perform, doing its special work 

 to a gauge or pattern, with an exactness which handicraft cannot equal. 

 By this means each watch movement, in every part with the exception of 

 the jewelled holes and the pivots that run in them is exactly like every 

 other of the same size and style. The holes are drilled in the jewels with a 

 diamond, and then opened with diamond dust on a soft, hair-like wire. The 

 steel pivots designed to run in these jewels, must be exquisitely polished, 

 by which operation their size is reduced almost inappreciably. After being 



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