Watch. A very small clock, made so as to be carried in a pocket without significantly altering its accuracy. This definition fits watches in general, but the term also relates to the shape of the clock and the arrangement of its parts; a carriage watch is as large as certain clocks, and it seems they were termed watches because they resemble ordinary watches in shape and construction.

The name reminds us that formerly the dial of a clock was called the display [ montre ], so the first clocks or pocket watches , since the whole mechanism was hidden by the case, were probably named for just what showed the time, namely the display.

It is not known exactly when they were first made; probably it was around the time of Charles V, for in his history we find that someone presented him with a clock of this kind as being something most unusual.

Since in watches it was necessary to substitute a spring for the weight that gave power to clocks, variations were soon observed, caused by variations in the power of the spring. Remedies were sought, and after several attempts the fusee was invented, surely one of the most ingenious discoveries ever made in mechanics. See Fusee.

To transmit the motion of the spring to the fusee, for a long time gut cords were used; they were another cause of variations because the cord grew longer and shorter with dryness and humidity, making the watch lose or gain several minutes in a short time. Eventually very fine steel chains could be made that replaced gut cords, and since the spiral spring was invented at about the same time, the face of horology was suddenly changed. These two discoveries, especially the latter, gave watches an accuracy that, no matter how accustomed to it we are, always surprises those who know something of the physical and mechanical difficulties that had to be overcome in order to attain that perfection.

Horologists distinguish several kinds of watches : plain, seconds, repeating, alarm, and three-part.

Plain watches simply show the hours and the minutes.

Seconds watches show the seconds in addition to hours and minutes. This is done in two ways, with the second hand at the center of the dial, or away from it; the latter type is called an off-center seconds watch . We shall see below how they are made.

Repeating watches strike the hours and quarters shown by the hands, when a plunger or button is pushed. See Repetition.

Alarm watches automatically ring at a determined time, to awaken you. See Alarm clock.

Striking watches automatically strike the hours, the halves, and sometimes the quarters, as time goes by. They are almost obsolete today. See Strike.

Three-part watches combine the properties of the last three, having repetition, alarm, and strike.

Further types of watches are distinguished: cord, going barrel, center winding, etc.; but these are no longer made; the ones still in existence were made long ago.

The first type was so named when chains were first used in watches .

The second came into use around the time when the spiral spring was discovered. It was so highly praised that clockmakers were persuaded that the fusee was useless, and they replaced it with the going barrel, which is simple a barrel with teeth around its circumference that mesh with the first pinion of the movement. When the spring was wound, it powered the watch , but experience soon showed clockmakers their error, and they abandoned this practice. See Barrel.

The third type results from the taste in decoration prevalent forty years ago. It was thought ugly to have a hole in the dial for winding the watch , and to avoid it this type of watch was invented; two wheels are located beneath the dial, one mounted on the fusee arbor and the other at the center of the dial. Since the two wheels mesh, turning the center wheel could wind the watch by means of the wheel on the fusee arbor. (This kind of watch showed only the hours, not the minutes.) As soon as Paris clockmaking began to flourish again, these watches were abandoned, and we must point out that the English, who were far ahead of us in clockmaking in those days, never indulged in such eccentricities.

A watch consists of its case and its movement. See our plates for the movement taken out of its case. The movement itself consists of various parts, some of which are more or less essential.