Great Melbourne Telescope

The Great Melbourne Telescope was built by Thomas Grubb of Dublin in 1868 and erected at Melbourne Observatory in 1869. It was a reflector telescope with a speculum (metal) mirror of 48 inches in diameter; at the time it was the second largest telescope in the world and the largest in the southern hemisphere.

The design and construction was overseen by a committee of eminent British astronomers, who developed the telescope to study the nebulae of the southern hemisphere skies. It was the first major telescope built by Thomas Grubb, and revolutionary in many aspects of its design. The firm went on to make many of the major telescopes around the world in the second half of the 19th century.

The telescope never lived up to expectations, due to difficulties with constant tarnishing of its mirrors, flexure in the mirrors, and its relative unsuitability for the new astronomical techniques of photography and spectroscopy. The telescope was operated at Melbourne Observatory by a dedicated Great Melbourne Telescope Observer: Albert Le Seuer (1869-70), E.F. MacGeorge (1870-72), Joseph Turner (1873-83), Pietro Baracchi (1883-92); thereafter it was used only intermittently.

When Melbourne Observatory closed in 1944, the telescope was sold to the Commonwealth Observatory at Mount Stromlo, Canberra. At Mount Stromlo the telescope was given a new 50-inch glass mirror, and became an integral part of Mt Stromlo's work during the 1960s. In the early 1990s the telescope was rebuilt with two detector mosaics for the MACHO project, and the telescope in this form found the first observational evidence for dark matter. Then in January 2003 a bushfire swept across Mt Stromlo, its firestorm destroying the majority of the telescopes and buildings.

Since the early 1980s Museum Victoria had progressively been retrieving discarded parts of the Great Melbourne Telescope as Mt Stromlo rebuilt the instrument. The remaining parts of the telescope at Mount Stromlo were dismantled in 2008 and returned to Melbourne. A project has now commenced to restore the telescope.

References:
Gascoigne, S.C.B. (1995). 'The Great Melbourne Telescope and other 19th century reflectors', Historical Records of Australian Science, 10, pp. 223-245.
Melbourne Observatory (1885). Observations of the Southern Nebulae made with the Great Melbourne Telescope from 1869 to 1885, Part 1. Government Printer, Melbourne.
Robinson, T. R. & Grubb, Thomas (1868). 'Description of the Great Melbourne Telescope', Proceedings of the Royal Society of London, 159, pp.127-161.