From the evidence adduced respecting the origin and inventors of the clock it is not unreasonable to conclude with Ferdinand Berthoud (a Frenchman who wrote much and was a great authority upon the subject) that such a clock as that which was constructed by Henry de Wyck for Charles the Wise of France, was not the invention of one man, but was the result of a series of inventions made at different times by various persons, each of which is worthy to be considered a separate invention. It was the simple employment of the natural force of gravity as to the fall of bodies in free space, that paved the way to the extreme accuracy and constancy of rate which belong to the clocks of modern times, and the conclusion to which Mons. Berthoud arrived respecting the progression of the essential improvements is thus stated:—
1. Toothed wheel-work was known in ancient times, and particularly to Archimedes, whose instrument was provided with a maintaining power, but had no regulator or controlling mechanism.
2. The weight applied as a maintainer at first had a fly, most probably similar to that of a kitchen-jack.
3. The ratchet-wheel and click for winding up the weight, without detaching the teeth of the great wheel.
4. The regulation of the fly depending upon the state of the air, it was abandoned, and a balance substituted.
5. An escapement next became indispensable, as constituting with the balance a more regular check than a fly upon the tendency which a falling weight has to accelerate its velocity.
6. The application of a dial-plate and hand to indicate the hours was a consequence of the regularity introduced into the going part.
7. The striking portion, to proclaim at a distance, without the aid of a watcher, the hour that was indicated: and this was followed by the alarum.
8. The reduction and accommodation of all this bulky machinery to a portable and compact size, as in watches.
Such a succession of ingenious contrivances, introduced by different men to improve upon the first rude instrument, is perfectly analogous to the successive improvements which have been made in the modern clock, since that of Henry de Wyck's was constructed. Large iron wheels, continually exposed to the oxidizing influence of the air, in which unequal and ill-shapen teeth were cut with the inaccuracy of a manual operation, were by no means calculated to transmit the maintaining power with perfect regularity to the balance, supposing it to have been a good regulator; but when it is further remembered that the alternate direct pushes of the escape-wheel against the pallets must have produced jerks, and destroyed, or greatly disturbed, the regularity of this most essential part of the mechanism, great accuracy was not to be expected; even minutes were deemed too small portions of time to be shown by such a machine. The clock was set daily by some person specially appointed to the office, and even then was not to be depended upon, for forty minutes' variation in twenty-four hours was not thought to be an ill performance.