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Free Pendulum Clock - William Shortt & Synchronome Co, London, No. 5, 1925 Object Reg. No: ST 028899

Impulse clock designed and built by William Hamilton Shortt, in association with the Synchronome Co, London, 1925 .

About 100 Shortt impulse clocks were made and used in observatories around the world. Shortt no. 5 was installed in the Melbourne Observatory in 1925, to run the Melbourne Observatory time service. It was transferred to the P.M.G. (Post-Master General) Research Laboratories in 1945, which took over Victoria's civil time service, and in 1955 transferred to the P.M.G. in South Australia, where it was used until 1968.

The clock comprises a free pendulum in an evacuated brass cylinder, and a slave pendulum in a Syncrhonome clock. The two pendulums swing together in precise sympathy, using a hit-and-miss synchronizer, so that the slave clock accomplishes the release of the gravity arm of the master clock and gives an impulse to the free pendulum.
Acquisition Information:
Donation from Australia: Post Master General's Department (PMG), 1972
Discipline: Technology
Dimensions: 140 cm (Height), 40 cm (Width), 20 cm (Length)
Dimension Comment: SLAVE CLOCK FREE PENDULUM: 140 X 30 X 28

More information

Tagged with: electric clocks, regulator clocks, time standards, horology
Themes this item is part of: Melbourne Observatory & Standard Time in Victoria, Horology Collection, Melbourne Observatory Collection, Science & Measurement Collection, Positional Astronomy at Melbourne Observatory, Weights & Measures at Melbourne Observatory, Astrographic Catalogue, Transits of Venus, 1874 & 1882, Buildings at Melbourne Observatory, Star Observations & Personal Equation, Meteorology at Melbourne Observatory, 1863-1908, Melbourne Observatory, 1863-1944, Geodetic Survey of Victoria, 1858-1872
Primary Classification: HOROLOGY
Secondary Classification: Clocks
Tertiary Classification: england
Manufacturer: Synchronome Co Ltd, London, Middlesex, England, Great Britain, circa 1925
Designer: Shortt, William Hamilton, England, Great Britain, circa 1925
Past Owner or User: Australia: Post Master General's Department (PMG), Melbourne, Victoria, Australia, 1945-1968
User: Melbourne Observatory, South Yarra, Victoria, Australia, 1925-1944
References: F. Hope-Jones, Electrical Timekeeping, 1940.

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