George Graham (clockmaker)
George Graham,
He was born in
Career
Graham was partner to the influential English clockmaker Thomas Tompion during the last few years of Tompion's life. Graham is credited with inventing several design improvements to the pendulum clock, inventing the mercury pendulum and also the orrery. He was made Master of the Worshipful Company of Clockmakers in 1722.[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.[4]
He was widely acquainted with practical astronomy, invented many valuable astronomical instruments, and improved others. Graham made for
Graham was introduced to John Harrison on the latter's arrival in London, and became a longtime advisor and supporter of Harrison's work on a marine chronometer. Graham and Harrison spent many hours discussing clockwork when first introduced, and Graham gave Harrison an unsecured and interest-free loan to continue his work at this first meeting. Graham later presented Harrison to the Board of Longitude, speaking on his behalf and securing additional funding from the Board.[5]
Deadbeat escapement
The
Achievements
His major contribution to geophysics was the discovery of the diurnal variation of the terrestrial magnetic field in 1722/23.[13][14] He was also one of the first to notice long-term secular change in the direction of the compass needle.[15] The compass needles he produced as an instrument-maker were used by many contemporary magneticians. Around 1730, George loaned approximately £200 to John Harrison so that he could start work on his marine timekeeper known later as H1. George was commonly known in the trade as 'Honest George Graham'.
Examples of his work
- A 28-day duration longcase regulator with deadbeat escapement c. 1745 Moyse's Hall Museum Bury St Edmunds UK
Death
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.[17]
In popular culture
Actor
See also
References
- ISBN 978-1-4614-7043-4.
- ^ "DServe Archive Persons Show". .royalsociety.org. Archived from the original on 13 January 2013. Retrieved 15 January 2012.
- ^ Watch-Wiki: George Graham
- ISBN 0-7110-3175-4(page 15)
- ^ Horrins, Joahn (1835). Wikisource. . Memoirs of a Trait in the Character of George III. of these United Kingdoms. London – via
- ^ Milham 1945, p.185
- ^ Glasgow 1885, p.297
- ^ Beckett, Edmund; Cunynghame, Henry Hardinge (1911). Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 06 (11th ed.). Cambridge University Press. pp. 536–553, see page 541, last few lines.
Dead escapements...To get rid of this defect the dead escapement......was invented by G. Graham.
. In - ^ "Deadbeat escapement". Encyclopedia of Clocks and Watches. Old and Sold Antiques Marketplace. Archived from the original on 20 May 2008. Retrieved 8 June 2008.
- ISBN 978-0-8153-1561-2. p.121
- ISBN 978-0-7503-0147-3. Letter 229 Flamsteed to Towneley (22 September 1675), p.374, and Annotation 11 p.375
- ISBN 978-0-8153-0615-3. p.126, this cites a letter of 11 December, but he may have meant the 22 September letter mentioned above.
- ^ Graham, George (1724): An Account of Observations Made of the Variation of the Horizontal Needle at London, in the Latter Part of the Year 1722, and Beginning of 1723. Phil. Trans. 33, 96–107, doi:10.1098/rstl.1724.0020
- ^ Graham, George (1724): Observations of the Dipping Needle, Made at London, in the Beginning of the Year 1723. Phil. Trans. 33, 332–339, doi:10.1098/rstl.1724.0062
- ^ Graham, George (1748): Some Observations, Made during the Last Three Years, of the Quantity of the Variation of the Magnetic Horizontal Needle to the Westward. Phil. Trans. 45, 279–280, doi:10.1098/rstl.1748.0030
- ^ 'The Abbey Scientists' Hall, A.R. p31: London; Roger & Robert Nicholson; 1966
- ^ Britten, Frederick J. (1894). Former Clock and Watchmakers and their Work. London: E. & F.N. Spon. p. 89. p.89-97
- ^ "Longitude © (1999)". Retrieved 22 June 2021.