I'm performing research on Robert Leslie for an upcoming article for the bulletin. MB readers may be interested to know that Robert Leslie of Philadelphia received a patent for a "chronometer" escapement signed by George Washington in 1789 shortly after Washington became President (Gould called it a "free balance" escapement in his famous 1923 book). A few years later, Leslie relocates to London to make his inventions and is granted patents there (he's also the inventor of the torsion pendulum clock) and in 1793 writes to Thomas Jefferson that four of his watches were sold to sea captains and more orders were pending. Unfortunately, none of his free balance pocket chronometers are know to have survived. This is the same guy that imported to Philadelphia and Baltimore under partnership names "Leslie & Price", "Robert Leslie & Company" and "Patton, Jones, & Company". If anyone has any Leslie-signed clocks or watches, I sure would be grateful to know. FYI, the NAWCC Museum has a Leslie & Price verge & fusee watch.