This clock was presented to the Royal Greenwich Observatory (RGO) in 1930 H.R. Fry of Barnet, an amateur astronomer who also presented the University of London with an 8-inch refractor by Cooke. A report of a visit to the RGO by the Electrical Horology Group of the Antiquarian Horological Society in 1977 mentions Shortt 40 thus:

‘The first item seen in the Time department of the Observatory was Shortt’s Free Pendulum No. SH40 with its specially constructed slave clock. The amateur astronomer Mr H.R. Fry commissioned the Synchronome Company to make the best-ever slave clock to go with his free pendulum which he presented to the observatory at Greenwich in 1936. The clock is fully jewelled throughout and much time and effort was lavished on finishing to the highest standard.’

This clock was first erected in the Flamsteed House clock cellar and in 1942 moved to the emergency time-station at Abinger. Shortly after this move it was relocated to the clock cellar at Herstmonceux castle and sometime in 1960 moved to outside the time service control room, also at Herstmonceux.

For a technical description of the Shortt Free Pendulum and Slave system see ZAA0539.