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Description: | Black painted brass and aluminium, wooden stand. Base plate: dia. 5.7" (14.5cm) graduated to 360 degrees by 1 degree. Centre part of base is rotated in azimuth by a tangent screw fitted to underside. A central spigot and three levelling legs attach base plate to wooden stand 7" (17.8cm) dia. Centre plate carries a pointer and two spirit levels 1.3" (3.5cm) long, one mounted N-S and E-W. Equatorial mounting: attached to centre plate. Adjustable for latitude and graduated 0-55 degrees. Ploar axis: fitted with a slow motion screw and clamp and white painted declination plate, graduated for North and South latitudes. Above the declination plate is mounted a bar with slit, through which a strip of sunlight shines on declination plate. A sighting tube 6.2" (15.6cm) long can be clamped to the bar, for observing Polaris. A scale with adjusting screw, graduated 20-0-20, for Equation of Time and Longitude correction, is attached to upper end of bar. At top of Polar axis there is a semi-circle graduated in hours 5-19, 5-19, and inscribed "RED FOR NORTHERN HEMISPHERE WHITE FOR SOUTHERN HEMISHERE" fitted with an indicator pointer in frame.
In wooden box lined with blue velvet 9 x 9 x 10" (22.9 x 22.9 x 25.4cm) containing an Equation of Time table.
AUDIT - object needs marking with its NAV number. Four unnumbered part numbers. | Publisher: | http://collections.rmg.co.uk/page/7d7ded6fb50d6031e2884961a200be58.html | Source: | Royal Museums Greenwich | Creator: | Instrument Developments Ltd | Identifier: | http://collections.rmg.co.uk/collections... | Go to resource |
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