Robert Leslie, Philadelphia, Baltimore & London

Recent exciting discovery! An American Chronometer Maker & Inventor of the "Nautical Watch"

Robert Leslie is best known as the principal in the Philadelphia firm Leslie & Price. However, few collectors know that he made both clocks and watches for Thomas Jefferson, was commissioned to make Jefferson's “Great Clock” at Monticello, and was in the forefront of invention in Philadelphia during the 1790's. In fact, Robert Leslie was awarded the first clock and the first watch patents in America, effective January, 1787, signed by George Washington. He received additional patents in both America and in England in 1793 that further evidence his work on some of the greatest challenges in horology at the time including constant force and chronometer escapements, pendent winding for watches, and torsion pendulums for clocks.

Leslie called one of his 1793 inventions the “Nautical Watch” which was intended to assist navigation at sea. This sophisticated timekeeper was the first two time-zone "captains" pocket watch made, and likely the first watch movement designed by an American. By the greatest of luck, a surviving example was discovered in rural southwest Virginia in 2012. Nautical Watch #5 is in its original wooden shipping box and was presumably manufactured as a salesman's sample to generate orders. It is configured with different hand styles and both front and rear winding to demonstrate the ways it could be ordered, and was also pre-tapped to allow easy installation of Leslie's patented pendent-wind invention. The movement has a going barrel (no fusee) and duplex escapement, although we know from recent research that it was also available with Leslie's chronometer escapement and temperature compensation. “No 5 Leslie’s Patent” is printed on the dial. The movement signature plate is engraved “Brearley, Philadelphia.” James Brearley is a listed Philadelphia maker and Leslie associate who apparently retailed Robert Leslie’s clocks and watches.

An article is being published about this important clock and watchmaker in the January/February and March/April NAWCC Watch & Clock Bulletin