Dry compass
Card-Mica covered with paper, white with black markings, graduated to 1/4 points. At centre of card is a hole 1" dia. to accommodate pivot.
Needle- Three edge bar needles (fourth missing) 2 x 3.75" and 1 x 2.75" long. Composed of laminated steel. Outer needle 0.25" deep with two laminations, inner needles 0.25" deep at ends having semi-circular swell at centre 1.25" dep, with four lamianations. The needles are 1" apart. Attached to a metal ring 3.25" dia. which is screwed to card.
Pivot-Inverted type (missing), two brass knee pieces for securing gimbal ring to inner needles, are in place.
Needle- Three edge bar needles (fourth missing) 2 x 3.75" and 1 x 2.75" long. Composed of laminated steel. Outer needle 0.25" deep with two laminations, inner needles 0.25" deep at ends having semi-circular swell at centre 1.25" dep, with four lamianations. The needles are 1" apart. Attached to a metal ring 3.25" dia. which is screwed to card.
Pivot-Inverted type (missing), two brass knee pieces for securing gimbal ring to inner needles, are in place.
For more information about using images from our Collection, please contact RMG Images.
Object Details
ID: | ACO0955 |
---|---|
Type: | Dry compass |
Display location: | Not on display |
Creator: | Preston, Grant |
Date made: | 1837-1840; 1837-40 |
Credit: | National Maritime Museum, Greenwich, London, Admiralty Compass Observatory |
Measurements: | Overall: 32 mm; Diameter: 100 mm |
Your Request
If an item is shown as “offsite”, please allow eight days for your order to be processed. For further information, please contact Archive staff:
Email: library@rmg.co.uk
Tel: +44 (0)20 8312 6516 (during Library opening hours)
Click “Continue” below to continue processing your order with the Library team.