George Graham (clockmaker)

[3] Between 1730 and 1738, Graham had as an apprentice Thomas Mudge, who went on to be an eminent watchmaker in his own right, and invented the lever escapement, an important development for pocket watches.

Graham made for Edmond Halley the great mural quadrant at Greenwich Observatory, and also the fine transit instrument and the zenith sector used by James Bradley in his discoveries.

He supplied the French Academy with the apparatus used for the measurement of a degree of the meridian, and constructed the most complete planetarium known at that time, in which the motions of the celestial bodies were demonstrated with great accuracy.

[6][7][8][9] However it was actually invented around 1675 by astronomer Richard Towneley, and first used by Graham's mentor Thomas Tompion in a clock built for Sir Jonas Moore, and in the two precision regulators he made for the new Greenwich Observatory in 1676,[10] mentioned in correspondence between Astronomer Royal John Flamsteed and Towneley[11][12] His major contribution to geophysics was the discovery of the diurnal variation of the terrestrial magnetic field in 1722/23.

He died at his home in Fleet Street, London[16] and was buried in the same tomb as his friend and mentor Thomas Tompion in Westminster Abbey.