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Date: |
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Description: | "W.N.T. Gilbert, 148 Leadenhall Street, London"
BARLOW'S PLATE for ADJUSTING COMPASSES first used in 1820
No 63 1848
The boxes are marked ACO0046.1-2 and can be found via the Whole/Part toggle.
Bowl-Dia. 7" (17.8cm) Black painted brass, balancing weight attached to bottom of bowl. Inside of bowl painted white with a black lubber line painted on side. Mounted in a brass gimbal ring 8.25" (21cm) dia. Mounted in a brass spigot to top of wooden pedestal.
Card-Dia. 6.25" (15.9cm) Mica covered with green paper with black markings, graduated to 16 points and quadrantally in degrees. A jewelled brass pivot cap is mounted at centre. Back of card has several blobs of wax for balancing card.
Needle-Length 6.25" (15.9cm) Lozenge shaped flat bar type secured to card by brass screws. Pivot cap is secured through the centre of needle.
Pivot-Steel pivot pin is mounted on a brass stem secured at centre of base of bowl.
Barlow's Plate-Dia. 16" (40.6cm) Consists of two thin circular discs of iron separated by a wooden disc. It is mounted at right angles to the wooden pedestal by a brass rod 12" (30.5cm) long, screwed to a socket on the stand, the other end passing through the centre of the disc and kept in position by means of a set screw.
caption: Record Shot - Do not reproduce. | Publisher: | "http://collections.rmg.co.uk/" | Rights holder: | "Royal Museums Greenwich" | Source: | Royal Museums Greenwich | Identifier: | http://collections.rmg.co.uk/collections... | Go to resource |
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