Brass framed sounding quintant.

Made:
1855-1865 in Poultry
maker:
John Dennett Potter

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© The Board of Trustees of the Science Museum

Sounding quintant with 6-inch radius limb, diamond-pattern anodized brass frame and silver inlaid scale marked -5° to 195° (169° range), 30 arc-min. divisions' with silver vernier scales to 1 arc-min. with wooden handle and Mahogany keystone box containing in the lid a label for Henry Porter (successor to William Cary), made by (William) Cary, London, 1855-1865. Fitted with tangent and clamping screws at back of the index arm; no shades; index-glass and horizon glass with screw and capstan screws adjustment; Detached telescope, (78 mm large objective) erect image with bracket without adjustment. Accessories include Screw-on diaphragm for the telescope; adjusting key; adjusting pin and magnifying glass (missing).

Details

Category:
Surveying
Object Number:
1876-992
Materials:
brass (copper, zinc alloy), cotton (fibre), ebony, felt, glass, iron, mahogany (wood), paper (fibre product) and steel (metal)
type:
sounding quintant
taxonomy:
  • furnishing and equipment
  • measuring device - instrument
credit:
Admiralty Hydrographic Department