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Date: |
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Description: | 73A Experimental card by Capt. Mayes 1877
No 73A
Card-Mica covered with paper, blue with blue and black markings, graduated to 1/4 points and quadrantally in degrees.
Needle- Four heavy needles, 2 x 6.5" and 2 x 4.5" long, each composed of threee laminations of steel, attached by rings and eyelets attached to brass ring 5.85" dia. and screwed to card.
Pivot Cone-shaped brass pivot cap with white metal bearing at top screwed through centre of light metal framework which has two short arms attached by rings and eyelets to the centre of the two inner needles and two long arms, carrying sliding weights, secured to metal ring of card.
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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