Double sounding quintant.

Double sounding quintant invented by Rear-Admiral Frederick Beechey, and made by William Cary, London, about 1847. Anodized brass frame, polished brass limb, a circular brass handle. Signed on the limb: Cary, London. Marked on the limb: Da.96. Inlaid silver scale with two graduations, the lower from the left from -35° to 165° every 30', measuring to 145°; the upper, from the right, from -15° to 155°, measuring to 158°. Two silver verniers to 1'; zero at the left (lower) and at the right (upper). The lower tangent screw and clamping screw are on the back of the index arm, which is on the back of the frame; the upper tangent screw is on the back of the index arm, the clamping screw is on the front. No shades. Two index glasses, adjustment by screws, one horizon glass with two silvered portions and clear glass in between; adjustment by a screw and a capstan screw. Threaded telescope bracket; perpendicular adjustment by rising-piece. Telescope (70 mm) erect image. No box.

Details

Category:
Surveying
Object Number:
1909-207
Materials:
brass (copper, zinc alloy), platinum (metal) and glass
Measurements:
overall: 75 mm x 186 mm x 120 mm, .785kg
type:
sounding quintant and double quintant
credit:
Board of Admiralty

Parts

Double sounding quintant

Double sounding quintant invented by Rear-Admiral Frederick Beechey, and made by William Cary, London, about 1847. Anodized brass frame, polished brass limb, a circular brass handle. Signed on the limb: Cary, London. Marked on the limb: Da.96. Inlaid silver scale with two graduations, the lower from the left from -35° to 165° every 30', measuring to 145°; the upper, from the right, from -15° to 155°, measuring to 158°. Two silver verniers to 1'; zero at the left (lower) and at the right (upper). The lower tangent screw and clamping screw are on the back of the index arm, which is on the back of the frame; the upper tangent screw is on the back of the index arm, the clamping screw is on the front. No shades. Two index glasses, adjustment by screws, one horizon glass with two silvered portions and clear glass in between; adjustment by a screw and a capstan screw. Threaded telescope bracket; perpendicular adjustment by rising-piece. Telescope (70 mm) erect image. No box.

Measurements:
overall: 75 mm x 186 mm x 120 mm, .785 kg
Materials:
brass (copper, zinc alloy) , platinum (metal) and glass
Object Number:
1909-207/1
type:
sounding quintant and double quintant
Image ©
The Board of Trustees of the Science Museum
Ring component for double sounding quintant

Ring component for double sounding quintant

Ring component for double sounding quintant invented by Rear-Admiral Frederick Beechey, and made by William Cary, London, about 1847.

Materials:
brass (copper, zinc alloy)
Object Number:
1909-207/2
type:
component
Image ©
The Board of Trustees of the Science Museum
component for double sounding quintant

component for double sounding quintant

Oval component for double sounding quintant invented by Rear-Admiral Frederick Beechey, and made by William Cary, London, about 1847. This appears to be hollow and oval in shape with three lines forming a point embossed on top.

Object Number:
1909-207/3
type:
component
Image ©
The Board of Trustees of the Science Museum