Astronomical and navigational instruments, Astrolabes and quadrants, Celestial navigation

The Collection

Your selection

Title

Actions

Buy this image Add this to a collection
Tags
Share or embed this object   
 

Mariner's quadrant

NAV1062
Astronomical and navigational instruments

Object connections:

Object details:

Object ID NAV1062
Description Brass mariner's quadrant. Brass scale 0°-90° by 30'. Shadow square 0°-50°-0° by 1°. Two sights and plumb line, probably a later replacement. Radius 153 mm. A polished brass quarter circle with two sights on the right-hand edge. The shadow square is used for taking altitudes in surveying. The back of the instrument is blank. The sights and plumb bob are probably later replacements. The Mariner's Quadrant is a simple instrument that enabled navigators to measure altitude. An object is observed through the sights and the weighted line gives the altitude above the horizon in degrees along the curved edge. This example also has a shadow square set out inside the main scale. This can be used for making basic surveying measurements. The reverse is blank.
Date made circa 1725

Artist/Maker Unknown
Place made England
Credit National Maritime Museum, Greenwich, London
Materials brass
Measurements Overall: 12 x 153 x 153 mm
Parts
Help us

Do you know more about this?

Share your knowledge