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Equatorial sector
This instrument is all that is left of the two 5ft equatorial sectors Sisson made for the Observatory.
This one was mounted in the new Observatory converted from Wren's summer house (what now houses the camera obscura). The sectors were mounted on the polar axis (an axis that points to the pole star) 3ft in from their centres. The original achromatic telescope had a 5ft focus of four inch apearture. The declination circle was 2ft in diameter and the hour circle was probably the same radius. Part of equatorial sector is mounted in the north-east terrace at ROG 1785 - 1811.
This part was removed in 1781 in an unsuccessful attempt to improve the instrument.
This one was mounted in the new Observatory converted from Wren's summer house (what now houses the camera obscura). The sectors were mounted on the polar axis (an axis that points to the pole star) 3ft in from their centres. The original achromatic telescope had a 5ft focus of four inch apearture. The declination circle was 2ft in diameter and the hour circle was probably the same radius. Part of equatorial sector is mounted in the north-east terrace at ROG 1785 - 1811.
This part was removed in 1781 in an unsuccessful attempt to improve the instrument.
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Object Details
| ID: | AST0964 |
|---|---|
| Collection: | Astronomical and navigational instruments |
| Type: | Telescope |
| Display location: | Not on display |
| Creator: | Sisson, Jeremiah |
| Date made: | 1773 |
| Credit: | National Maritime Museum, Greenwich, London |