BERTHOUD, Ferdinand, a celebrated Swiss chronometer-maker, was born in Neufchâtel. The date of his birth is variously given as 1725, 1727, and 1729. His father was an architect, and the son was intended for the church; but, showing a taste for mechanics, he was placed under an experienced workman to be instructed in clock and watch making, and was afterwards sent to Paris to improve himself in the knowledge and practice of the art. He settled in Paris in 1745, and applied himself to the making of chronometers, an art which was then in its infancy. He soon attained distinction for the excellence of his workmanship and the accuracy of his chronometers. Fleurieu and Borda, by order of the French Government, made a voyage from La Rochelle to the West Indies and Newfoundland for the purpose of testing them, and they found that they gave the longitude with an error of only a quarter of a degree, after a cruise of six weeks. Satisfactory results were also obtained in the expedition of Verdun, Borda, and Pingré, which was appointed to try these chronometers and those of his only rival, Le Roy. Sully, an English watchmaker established in Paris, was the first who in that city attempted the construction of chronometers for finding the longitude; and this he did in 1724. In 1736 the chronometers of the English artist Harrison were tried at sea. In France, however, there were no chronometer-makers of note after Sully, till Pierre le Roy and Ferdinand Berthoud, between whom there was some discussion about the priority of their discoveries and improvements. Ferdinand Berthoud’s chronometers were long the most esteemed of any in France. Louis Berthoud, his nephew and successor, introduced some improvements, and made chronometers of a smaller size and therefore more portable. ...