The Great Melbourne Telescope was built by Thomas Grubb in Dublin, Ireland in 1868, and installed at the Melbourne Observatory in Melbourne, Australia in 1869.[1]
The telescope had a 48-inch-diameter (1,200 mm) speculum primary mirror, and was mounted on an equatorial mounting. The design had been approved by a committee of leading British astronomers and scientists.[2] At the time of commissioning it was the second largest telescope operating in the world, after Lord Rosse’s 6 foot reflector at Birr, Ireland.[3]
The telescope was designed to explore the nebulae visible from the southern hemisphere, and in particular to document whether any changes had occurred in the nebulae since they were charted by John Herschel in the 1830s at the Cape of Good Hope.[4]
After some initial teething problems, the telescope was used for about 20 years at Melbourne Observatory, and one volume of observations produced, along with spectroscopic observations and some pioneering attempts at photographing nebulae. The difficulties of repolishing the mirror and the telescope’s relative unsuitability for photography deterred further use.[5]
When Melbourne Observatory closed in 1945, the Great Melbourne Telescope was sold to the Australian Government’s Mount Stromlo Observatory near Canberra. It was rebuilt in the late 1950s with modern drive and a new 50-inch (1,300 mm) pyrex mirror. In the early 1990s the telescope, still utilising Grubb’s original equatorial mounting, was rebuilt with two CCD arrays to detect MACHOs (massive astrophysical compact halo objects).[6]
In 2003 a bushfire destroyed the telescopes and buildings at Mount Stromlo. The fire-ravaged remnants of the 50-inch telescope were transferred to Museum Victoria, which had previously acquired discarded parts of the original telescope in 1984.[7]
A project is now underway to restore the Great Melbourne Telescope and, if feasible, reinstate it in its original building at the former Melbourne Observatory site.