The honours of the invention of the pendulum-clock have been contested by Vincentio Galilei, son of the great astronomer, who is said to have made a pendulum-clock at Venice in 1649, and Christian Huygens, a noted Dutch mathematician, who (in his excellent treatise, 'De Horologio Oscillatorio,' which was the foundation of most of the subsequent improvements in horometrical machines) clearly shows that he had constructed a pendulum-clock previous to 1658. His reputation will be somewhat obscured, however, if we yield to the claims of an Englishman named Richard Harris, an ordinary workman, who, it is said, invented the pendulum-clock which was fixed in the turret of St Paul's, Covent Garden, in 1642, and which is generally believed to have been the first pendulum-clock in Europe. The pendulum when first applied to clocks was suspended by a silken cord, and the arc described by the bob or weight at its end was a segment of a circle, but it being found that this was in opposition to scientific knowledge, and that the curve described by it should properly be part of a cycloid or oval; Huygens tried to remedy the error by causing the silk cord in its motion to side or strike against a curved piece of brass, but he thereby caused a greater error than he corrected. Dr Hooke afterwards suspended the pendulum by a thin flexible piece of steel, the bending of which, as the pendulum swings from side to side, produces the required cycloidal motion. In 1658 Dr Hooke invented the Anchor Escapement which is still in use together with the flexible spring to the pendulum above described. Before, however, we proceed further with our historical summary of the progress of watch and clock making, it may be well to introduce here two illustrations of the watches worn by two of the most eminent Englishmen of about this period. +----------------------------------------------------------------------+ | [Illustration: Ancient Box Watch.] | | | | [Illustration: The Watch of Oliver Cromwell.] | +----------------------------------------------------------------------+