This pivot testing apparatus was used in conjunction with one of The Sydney Observatory's transit telescopes. Which one is unclear but it is most likely of nineteenth century origin.

The firm of Troughton and Simms made pivot testing equipment for the six inch transit telescope H9899 but it is unclear whether this apparatus is related to that particular telescope. Pivot testing equipment was specially designed to test the circularity of the pivots in telescopes. This was to ensure the pivots on which the telescope turned were on exactly the same level as they had to point exactly east and west and the angle of the telescope needed to be exactly at right angles to the line joining the pivots in all directions. The errors which crept in were checked daily making pivot testing equipment a significant part of any observatory's equipment.

References
Russell, H., C., "Report of Astronomer for 1874 & 1875', New South Wales Government Printer, 1876
Royal Observatory publication, unacknowledged photocopy, blue file H9899

Geoff Barker, August, 2007

The pivot testing apparatus was used at Sydney Observatory, Watson Road, Observatory Hill, Sydney, New South Wales, Australia.

Astronomical equipment, pivot testing apparatus, wood / glass / metal / paper / ink, used at Sydney Observatory, maker unknown, 1877-1907

Pivot testing apparatus contained within a wooden box with a lid. The pivot testing apparatus consists of a large brass cylinder that tapers towards one end, a smaller brass tube with screw fittings on either end, three lenses, an eyepiece and paper envelope containing ten metal screws.

Made: 1877 - 1907


Used: Sydney Observatory; Sydney Observatory

H10306

1877 - 1907