Regulator Clock - Robert Ellery, Melbourne Observatory, 1888

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Summary:: Astronomical regulator clock designed by Government Astronomer Robert Ellery and built at Melbourne Observatory in 1888. The clock was probably made by Observatory instrument maker Carl Otto.

Ellery designed this clock to send time-signals by telegraph line from Melbourne Observatory to the time-ball at Williamstown. The time signal dropped the time-ball precisely at one o'clock each afternoon, thereby enabling ships's officers in the port to check the rate of their chronometers.

Ellery designed the clock so that it would give a prolonged electrical contact, thereby generating an appropriate electrical signal. 'I therefore designed a controlled pendulum clock, in which the pendulum drives the seconds wheel and hand, and thence the minute and hour hands. The seconds wheel closes contact springs in the usual way as each tooth passses, but, as the motion of the wheel is slow as that of the pendulum, the contact is sufficiently prolonged to obviate all difficulty complained of as regards adjustment of line relays.' Report of the Government Astronomer, 1888, p. 6.
Description:: Weight driven; deadbeat escapement. Pendulum has steel shaft with cylindrical brass bob.Separate dials for minutes, seconds, and hours.
Acquisition Information:: Donation from L. Smith, 1967

Discipline:	Technology
Dimensions:	141 cm (Height), 41 cm (Width), 26 cm (Length)

Tagged with:	longcase clocks, regulator clocks, time standards
Themes this item is part of:	Robert Lewis John Ellery, Astronomer & Scientist (1827-1908), Melbourne Observatory & Standard Time in Victoria, Carl M. Otto, Scientific Instrument Maker (circa 1860-?), Horology Collection, Measure Island, Melbourne Observatory Collection, Science & Measurement Collection, Great Melbourne Telescope, Positional Astronomy at Melbourne Observatory, Positional Astronomy at Melbourne Observatory, Weights & Measures at Melbourne Observatory, Mapping the Stars at Melbourne Observatory, Astrographic Catalogue, Transits of Venus, 1874 & 1882, Buildings at Melbourne Observatory, Star Observations & Personal Equation, Meteorology at Melbourne Observatory, 1863-1908, Meteorology at Melbourne Observatory, 1863-1908, Williamstown Observatory, 1853-1863, Melbourne Observatory, 1863-1944, Melbourne Observatory, 1863-1944, Geodetic Survey of Victoria, 1858-1872, Geodetic Survey of Victoria, 1858-1872
Primary Classification:	HOROLOGY
Secondary Classification:	Clocks
Tertiary Classification:	australia
Inscriptions:	Round silvered dial marked "REGULATOR ROBERT J. ELLERY MELBOURNE".
Designer:	Mr Robert Ellery, South Yarra, Victoria, Australia, 1888
Maker (Probable):	Carl Otto, South Yarra, Victoria, Australia, 1888
User:	Melbourne Observatory, South Yarra, Victoria, Australia, 1888