|
Date: |
|
Description: | 1839 Compass No 1 Card No 1 Capt E.J.Johnson Experimental No 11
No 1
Card-Mica covered with paper, white with black markings, graduated to 32 points.
Needle- Single needle 4.4" long composed of six thin laminations of steel placed edgeways to card, the strips are shaped into two semi-circles at centre of card, forming an aperture for the jewel cap. The laminations are secured together by two small brass clamps which are screwed to card. Two rectangular pieces of brass are attached in the E-W line.
Pivot- Cone-shaped brass pivot cup with jewel at top, screwed through centre of a light brass bridge piece which is secured to the centre of needle. A counter nut screwed to face of card above pivot cap has a recess that was to accommodate a style pin depending from the compass glass, to prevent card detaching from pivot.
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 |
|
|