2 0 0 9 P a r i s / M e u d o n

IWCMO Conference


Talk at the IWCMO meeting, Paris, 18th September 2009



he Great Melbourne Telescope was a 48 inch reflecting telescope installed at Melbourne Observatory in 1869. The telescope was a Cassegrainian configuration and was designed and built in Dublin, Ireland by Thomas Grubb and his son Howard. The telescope was provided with two primary mirrors of speculum metal. These were the last large speculum metal mirrors made by Grubb and the plan was to employ one mirror in the telescope while the other was being repolished and refigured. Figure 1 shows a line drawing of the telescope.




The following specifications are of interest.


Diameter of the primary mirror 48 inches. (1.2 meters)

Focal length 30 6煤 (9.3 meters)

Secondary amplification approx. 6

Magnification 220x to 1000x

Mass of moving parts 8.24 tonnes.



Figure 2 shows the telescope being assembled in 1869 and Fig. 3 shows the completed instrument.



In 1873 J. Turner took a prime focus photograph of the 9 day old Moon (Fig. 4) and made several drawings of Mars (Fig. 5).















In 1894 the director of Melbourne Observatory, Robert Ellery made some drawings of Mars with descriptions (Fig. 6). These reproductions are poor and we continue to search the archives for the original work.


In 1945 the telescope was relocated at Mt Stromlo Observatory near Canberra. The telescope was fitted with a new 50 inch glass mirror and the mounting was modernized including an electronic drive. It was involved in serious astronomical research until 2003 when it was seriously damaged in the Canberra bushfires (Last picture).




Members of the Astronomical Society of Victoria are now working on restoring the telescope to its original 1869 appearance. A feasibility study is now underway to determine the possibility of mounting the instrument as a working telescope back in Melbourne.


Barry ADCOCK, Astronomical Society of Victoria, Melbourne, Australia

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