Watch′making. With the invention of coiled springs as the source of power in time-pieces, it became possible to make them small enough to put in the pocket. Now that clocks also are made with springs, the difference between them and watches is simply a matter of size. The first watches were made, it is said, in Nuremberg about 1500, and on account of their shape and size were called Nuremberg eggs. The early watches were made in many curious shapes, and indeed, before the modern day of hurry and necessity for promptitude, they were of little use. To overcome the variations in power as the spring uncoiled, the fusee and chain were used, the fusee being the axle on which the chain was coiled. Watches were not exact, and had only an hour-hand till Hooke in 1658 invented the balance-wheel, including the hair-spring. It is used to take the place of a pendulum, which of course can not be used in a watch. The next step was the invention of the lever escapement about 1770, which applies the regulation of the balance-wheel with much more accuracy than had been attainable. The fifth important step was the invention of the compensating balance. Watches are more affected by changes in temperature than are clocks, and it was necessary so to arrange different metals in the balance that the contraction or expansion of one would offset that of the other. This invention (1764) made possible the exactness of the chronometer, which in turn enables sailors to tell their longitude with precision. Perhaps the invention of stem-winding and stem-setting to take the place of the key so easily lost deserves the sixth place. The latest development is the application of machinery to the manufacture of watches, and this was brought about by American ingenuity about 1854, when the celebrated factories at Waltham (q.v.) were established. Not only does machinery make the parts more exactly than hand-labor, but this exactness makes it possible to dispense with the fusee and chain. The American watch has about 153 parts to the 800 parts that had to be brought together in the British or the Swiss watch. Improved methods of hardening steel made jewel-bearings less important, and so the way was prepared for the "dollar watch." Before machinery was applied, the parts of any one watch had to be specially made for it; but now the parts of a watch never face each other till they are ready to go into the case together. Being made of standard sizes, they always fit. Watch manufactories are now scattered over the north of the United States, but the chief centers are in Massachusetts, Connecticut, New York and Illinois. England and Switzerland make the better, Germany the cheaper, watches.