Astronomical Regulator: Graham 1


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When Edmond Halley arrived at the Observatory as the new Astronomer Royal in 1720, all the instruments had been removed by the widow of his predecessor John Flamsteed. Made by George Graham, this is one of a pair of clocks purchased by Edmond Halley as part of his re-equipping of the Observatory. Delivered in about 1725, it is now in the care of the National Maritime Museum (Object ID: ZBA2211). Over the course of its life it underwent a number of modifications including re-casing in 1791.

Airy's Altazimuth Telescope. The clock Graham 1, which was initially used to time the observations, can be seen in the alcove in the left. First published in an article by Edwin Dunkin in the 1862 volume of The Leisure Hour, the image was later reprinted in the 1891 edition of Dunkin's The Midnight Sky. Probably based on the image first published by Airy in 1847, the inclusion of the three figures helps gives the instrument a sense of scale


1893 April 1, Altazimuth Dome (Airy's). Sidereal recorded as being transferred to New Altazimuth (Christie's). No date (RGO39/10/39)

1954 inventory (RGO71/1/3/1): 'In Visitor's Room, Greenwich until 1840. Removed to Abinger and set up at "Cornerways". Transferred tp Time Dept. Office, Abinger, 1944?'. Cornerways was the name of the house requisitioned for the Astronomer Royal to live in at the start of WW2. It also housed his office.

1952/3: Overahuled in Chronometer workshop (1953 Report)

After 1954, but by 31 December 1957 when the Abinger site was vacated and handed over to Admiralty Works Department

1960: Running in the office of the Head of the Time Department, Humpry Smith, at Herstmonceux. No info as to when it was errected

Airy's Altazimuth Telescope

Christie's Altazimuth Telescope


it is thought that Graham made less than two hundred clocks of all types, numbered from about 585 to 780.

Graham 1 numbered 621 on the backplate
Graham 2 numbered 675 on the backplate
Graham 3 unumbered on the backplate

Comparison clocks:



No 613




Clock numbered 625 on backplate.


No. 662 
No 638


No 668

680 (NMM)

No 681 (originally sold by to Robert Cay in 1728 for 16  gns) see  write up to 662

No 689

707  (1733)