WATCH, is also used for a small portable movement, or machine, for the measuring of time; having its motion regulated by a spiral spring.
Watches, strictly taken, are all such movements as show the parts of time; as clocks are such as publish it, by striking on a bell, &c. But commonly the name watch is appropriated to such as are carried in the pocket; and clock to the large movements, whether they strike the hour or not. See CLOCK.
The invention of spring or pocket watches belongs to the present age. It is true, we find mention made of a watch presented to Charles V. in the history of that prince: but this, in all probability, was no more than a kind of clock to be set on a table, some resemblance whereof we have still remaining in the ancient pieces made before the year 1670. There was also a story of a watch having been discovered in Scotland belonging to King Robert Bruce; but this we believe has turned out altogether apocryphal. The glory of this very useful invention lies between Dr Hooke and M. Huygens; but to which of them it properly belongs, has been greatly disputed; the English ascribing it to the former, and the French, Dutch, &c. to the latter. Mr Derham in his Artificial Clockmaker, says roundly, that Dr Hooke was the inventor; and adds, that he contrived various ways of regulation. One way was with a loadstone: Another with a tender straight spring, one end whereof played backwards and forwards with the balance; so that the balance was to the spring as the bob to a pendulum, and the spring as the rod thereof: A third method was with two balances, of which there
were divers sorts; some having a spiral spring to the balance for a regulator, and others without. But the way that prevailed, and which continues in mode, was with one balance, and one spring running round the upper part of the verge thereof: Though this has a disadvantage, which those with two springs, &c. were free from; in that a sudden jerk, or confused shake, will alter its vibrations, and put it in an unusual hurry.
The time of these inventions was about the year 1658; as appears, among other evidences, from an inscription on one of the double balance watches presented to King Charles II. viz. Rob. Hooke inven. 1658. T. Tompion fecit, 1675. The invention presently got into reputation, both at home and abroad; and two of them were sent for by the dauphin of France. Soon after this, M. Huygens's watch with a spiral spring got abroad, and made a great noise in England, as if the longitude could be found by it. It is certain, however, that his invention was later than the year 1673, when his book de Herod. Oscillat. was published; wherein he has not one word of this, though he has of several other contrivances in the same way.
One of these the lord Brouncker sent for out of France, where M. Huygens had got a patent for them. This watch agreed with Dr Hooke's in the application of the spring to the balance; only M. Huygens's had a longer spiral spring, and the pulses and beats were much slower. The balance, instead of turning quite round, as Dr Hooke's, turns several rounds every vibration.
Mr Derham suggests, that he has reason to doubt M. Huygens's fancy first was set to work by some intelligence he might have of Dr Hooke's invention from Mr Oldenburgh, or some other of his correspondents in England; and this, notwithstanding Mr Oldenburgh's attempt to vindicate himself in the Philosophical Transactions, appears to be the truth. Huygens invented divers other kinds of watches, some of them without any spring or chain at all; which he called, particularly, pendulum watches.
Striking WATCHES are such as, besides the proper watch-part for measuring of time, have a clock-part for striking the hours, &c.