Henry de Vick of France about 1370 constructed a celebrated clock for Charles V., the first nearest approach to modern weight clocks. The weight was used to unwind a cord from a barrel. The barrel was connected to a ratchet and there were combined therewith a train of toothed wheels and pinions, an escapement consisting of a crown wheel controlled by two pallets, which in turn were operated alternately by two weights on a balanced rod. An hour hand was carried by a shaft of the great wheel, and a dial plate divided into hours. This was a great advance, as a more accurate division of time was had by improving the isochronous properties of the vibrating escapement. But the world was still wanting a time-keeper to record smaller portions of the day than the hour and a more accurate machine than Vick’s. Two hundred years, nearly, elapsed before the next important advance in horology. By this time great astronomers like Tycho Brahe and Valherius had divided the time-recording dials into minutes and seconds. About 1525 Jacob Zech of Prague invented the fusee, which was re-invented and improved by the celebrated Dr. Hooke, 125 years later. Small portable clocks, the progenitors of the modern watch, commenced to appear about 1500. It was then that Peter Hele of Nuremberg substituted for weights as the motive power a ribbon of steel, which he wound around a central spindle, connecting one end to a train of wheels to which it gave motion as it unwound. Then followed the famous observation of the swinging lamp by the then young Galileo, about 1582, while lounging in the cathedral of Pisa. The isochronism of the vibrations of the pendulum inferred from this observation was not published or put to practical application in clocks for nearly sixty years afterward. In 1639 Galileo, then old and blind, dictated to his son one of his books in which he discussed the isochronal properties of oscillating bodies, and their adaptation as time measures. He and others had used the pendulum for dividing time, but moved it by hand and counted its vibrations. But Huygens, the great Dutch scientist, about 1556 was the first to explain the principles and properties of the pendulum as a time measurer and to apply it most successfully to clocks. His application of it was to the old clock of Vick’s. The seventeenth century thus opened up a new era in clock and watch making. The investigations, discoveries, and inventions of Huygens and other Dutch clock-makers, of Dr. Hooke and David Ramsey of England, Hautefeuille of France, and a few others placed the art of clock and watch making on the scientific basis on which it has ever since rested.