Wonders of a Watch.

New Zealand Tablet, Volume XXX, Issue 47, 20 November 1902, Page 29

Wonders of a Watch.

1 Much in little ' can be said more truly of a first-class American watch than of almost any other product of human ingenuity and industry. The watch one carries in his pocket, unless it is of the cheapest ' pocket-clock ' variety (says an American exchange), has in its movement more than 150 parts, and thiß number does not include the case which holds the movement. A glance at the movement is enough to show that some of its parts are very small, bat oue oan scarcely realise how minute some of them are. Take, for example, the numerous screws which hold the part* together. Some of them are ao tiny that it takes nearly 150,000 of them to weigh a pound. One must use a good microscope to eea the threads in these sorewß, and each of the threads must be absolutely perfect and true, or the eorew is useless. There are screws in a small-si eed watch, such as women usually carry, which have a thread of 260 to the inch. The weight of one of these Bcrews is one one-hundred and thirty thousandth of a pound. The diameter of the pivnt of the balance wheel in a watoh la only one two-hundredth of an inch, and pivots are classified by a gauge which measures down to one ten-thousandth of an inch. The jewel hole into which the pivot fits ia one five-thoueandth of an inch larger than the pivot, so that the latter may have sufficient play. Jewels in a watoh movement are out from slabs of garnet, ruby, or sapphire, one-fiftieth of an inch thick. Then they are ' surfaced,' drilled through the centre, and on the convex side a depression is made for an oil cup. A pallet jewel, finished and in use, weighs one one-hundred apd fiftieth thousandth of a pound, while the weight of a roller jewel is a fraction more than one two-hundred and fifty-six thousandth of a pound. The largest hairspring stud is four one-hundreds of an inch in diameter, and nine one-hundreds of an inch in length. To make the complete movement of a good watoh more than 8700 different processes are employed. It takes about five months to complete a single watch of the best grade, but as all the proceßses are carried on simultaneously, the finished produot is turned out continuously by the manufacturers. The balance in a modern watoh must make 18,000 vibrations every hour. A change in only one beat will cause the watoh to gain or lose four and four-fifth seconds in 24 hours. Think of the wonderfully delicate mechanism and equally delicate adjustment that puts altogether more than 150 pieces of almost microscopical size and turns out a watoh that will not vary one second in 24 hours ; and then take off your hat to the American manufacturer who, by doing this, has taken the lend of the whole world in the making of watches.