50.3 MB (2.1 MB compressed)
5197 x 3381 pixels
43.9 x 28.7 cm ⏐ 17.3 x 11.3 in (300dpi)
ROYAL ASTRONOMICAL SOCIETY / SCIENCE PHOTO LIBRARY ROYAL ASTRONOMICAL SOCIETY / SCIENCE PHOTO LIBRARY
Almucantar instrument at the Case Observatory, Ohio, USA. This almucantar was built by the US astronomer Charles S. Howe in 1900, improving on the initial almucantar design by S. C. Chandler in 1879. An almucantar is designed to be used like a transit circle, to determine the position of stars and other astronomical objects, but is designed to be steadier and easier to use, leading to improved results. The design seen here involves four stone pillars supporting an iron ring-shaped box. This box contains mercury in which floats a ring-shaped support for the telescope (rectangular object on top of the ring-shaped box). A set of iron weights in the centre stablises the apparatus. The telescope dome's observing aperture is seen in the background, and measurements in degrees are seen on the apparatus and dome.
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