Ramsden
JESSE, an English mathematical instrument-maker; born in Salterhebble, near Halifax, Yorkshire, England, in 1735. He began life as a cloth worker. About 1755 he moved to London, and shortly afterward began to work as an engraver. He spent his best efforts in effecting improvements in the sextant, theodolite, equatorial, barometer, micrometer, mural quadrant, etc. He so improved the sextant that its range of error was diminished from 5 minutes to 30 seconds. He made the theodolite for the ordnance survey of England. He devised the mural circle, and made the first for Palermo and Dublin.
He spent several years over an instrument for graduating mathematical `instruments and published an account of it as "Description of an Engine for Dividing Mathematical Instruments" (1777). He was elected a Fellow of the Royal Society in 1786, and was voted the Copley medal in 1795. He died in Brighton, England, Nov. 5, 1800.