3 ¾-inch transit telescope, made by Edward Troughton
There are two main types of telescopes. One uses a curved reflecting mirror to capture an image of celestial bodies the other uses a refracting lens to gather the light.
This telescope is one of the instruments which arrived in Australia with Governor Brisbane in late 1821. In the following year it was installed in the observatory built next to Government House at Parramatta. The telescope was made by Edward Troughton, one of the most respected instrument makers of the day, and was originally used to observe the right ascension of the stars.
After Brisbane left in 1825 the instrument was brought by the New South Wales State Government and was for a time used for recording transits. James Dunlop was appointed as astronomer at the observatory in 1831 and upon his return to Australia Dunlop had found the equipment in a bad state of repair. Nevertheless he commenced observations around the middle of January 1832 using the Troughton transit and mural instruments. In 1835 a new transit telescope made by Jones was delivered to the observatory which replaced the Troughton transit. The Jones telescope however proved too difficult for Dunlop to manage on his own and instead he used the Troughton mural circle (H9893) for most of his observations. The instrument was put into storage after the Parramatta observatory was closed down in 1847 and remained so until the new Sydney Observatory was built above the Rocks.
The opening of the new observatory in 1858 saw many of the original Brisbane instruments taken out of storage. Given their age it is not surprising that the new Government Astronomer Rev. W. Scott found many of them, like this telescope, could be not be used. Instead he favoured the Jones transit circle (now lost), the equatorial made by Banks (H9888) and the long case clock made by Hardy (H9889).
In 1858 and 1859 Scott did use the telescope while he was waiting for the return of the Jones Transit which had been sent to England for repairs by Governor Denison in 1855. Significantly it was used to make the first determinations of longitude of Sydney Observatory an essential step in the surveying of New South Wales. However Scott was not happy with its performance as he felt it had problems with its pivots and axis.
Even with its faults, and the subsequent loss of the front lens, this instrument remains of national significance due to its pioneering role in Australian science and its association with Australia's earliest astronomers. It is also significant for its association with early nineteenth century astronomical instruments and their makers.
Orchiston, W., 'Mission Impossible: William Scott and the First Sydney Observatory Directorship', cited in Journal of Astronomical History and Heritage, Volume 1,Part 1, 1998 pp: 21-43
Lomb, N., 'Earnshaw's Excellent Timekeepers', in Davison, G., Webber, K., 'Yesterday's Tomorrows; the Powerhouse Museum and its precursors 1880-2005', Powerhouse Publishing, 2005
Scott, W., Astronomical Observations made at the The Sydney Observatory in the Year 1860, Thomas Richard, Government Printer, Sydney, 1861
Scott, W., Astronomical Observations made at the The Sydney Observatory in the Year 1859, Thomas Richard, Government Printer, Sydney, 1860
Haynes, Raymond, Haynes, Roslynn, Malin, David, McGee, Richard, Explorers of the Southern Sky, Cambridge University Press, 1996
Forwarded to H. M. Secretary of State by Despatch, No. 141, 1847, Federation and Meteorology, http://www.austehc.unimelb.edu.au/fam/1541.html
Significance Statement by Geoff Barker, August, 2007