Equinoctial dial
Equinoctial dial for latitude 30° North. This dial has a shaped brass base with three flower-headed levelling screws. At the centre of the base is a support for the vertical circle segment. At the North end of this, an equinoctial hour dial is held against the ring by a screw on which the numbers for every other hour are engraved in red. A screw on the South of the segment supports a horizontal compass. This has a white base marked with a red meridian line and a blued needle surmounted by a brass pyramidal pivot. A glass plate covers all. A screw at the top point of the segment supports a string plumb line and a brass plumb bob suspended over a brass pillar. A screw also supports the string gnomon which is perpendicular to the dial-plate.
This unusual form of equinoctial dial shows clear Western influence, as opposed to the 'pseudo-equinoctial' boxwood dials such as AST0378, AST0426 and AST0428.
For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.
This unusual form of equinoctial dial shows clear Western influence, as opposed to the 'pseudo-equinoctial' boxwood dials such as AST0378, AST0426 and AST0428.
For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.
For more information about using images from our Collection, please contact RMG Images.
Object Details
ID: | AST0334 |
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Collection: | Astronomical and navigational instruments |
Type: | Equinoctial dial |
Display location: | Not on display |
Creator: | Unknown |
Date made: | 19th century |
Credit: | National Maritime Museum, Greenwich, London, Caird Collection |
Measurements: | Overall: 14.5 x 75 x 109 mm |