POWERHOUSE COLLECTION

A 16 inch repeating circle

Object No. H9892

This astronomical instrument circle was made in Germany by 'Reichenbach, Utzschneider and Liebherr' and was purchased by the amateur astronomer Sir Thomas Brisbane sometime between 1804 and 1814. In 1821 Brisbane arrived in New South Wales as the newly appointed Governor of the colony and this instrument is one of a number which he brought with him to house in Australia's first official observatory at Parramatta. The instrument consists of two 2-inch refracting telescopes mounted on a 16-inch circle, which allowed astronomers to measure the angle between selected stars. In the 1820s it was used at the Parramatta Observatory to make the first readings of the cluster of stars around Kappa Crucis since 1750 but it was put into storage when the Parramatta Observatory was closed down in 1847. Eleven years later, when the new Sydney Observatory was opened, the original Brisbane instruments were taken out of storage for re-use but the Government Astronomer Rev. W. Scott found many, including this repeating circle, were no longer usable as primary recording instruments. But this was not the end of the repeating circle's valuable contribution to science in Australia. In 1872 H. C. Russell, the then Government Astronomer, dusted off one of the telescopes and used it to look again at the cluster of stars around Kappa Crucis. These measurements he used to compare with the results he had made using the large 7 1/4 -inch Schroeder telescope then installed in the Observatory. And around 100 years after its arrival in Australia, the repeating circle was again drafted into use and modified for making observations of the eclipse of the sun at Goondawindi in 1922. In that year William Cooke, the Government Astronomer noted, "The Sydney Observatory possesses no field instrument suitable for time observations, yet it was essential to our program that our chronometers should be properly rated. In an almost forgotten cupboard the old "repeating circle" of Sir Thomas Brisbane was found covered with rust and dust. This was practically obsolete even in its time a century ago, and is certainly the most ancient astronomical instrument in Australia. It was cleaned in our workshop and fitted with a new telescope and transit micrometer, and converted into quite a modern form of almucantar instrument. It was then taken to Goondawindi and mounted on a concrete pier ..." While this instrument was re-used and modified over the course of its life it 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 some of most respected early European nineteenth-century scientific instrument makers. Geoff Barker, Assistant Curator, 25 October 2010 References Lomb, N., 'The Instruments from the Parramatta Observatory', in Historical Records of Australian Science, 2004, 15 De-Clerq, P.R., Nineteenth Century Instruments and their Makers; Rodopi, Amsterdam, 1985 King, H., C., The History of the Telescope, Dover Publications, New York, 1955 Total Eclipse of the Sun, 1922, September 21, Sydney Observatory Monograph, Alfred James Kent, Government Printer, 1923