Octant - Spencer Barret & Co., London With Keystone Box

Octant - ebony "T" frame supporting the large inlaid ivory arc scale. The scale is graduated every 20 minutes from -3° to +109° and read by vernier with tangent screw to single minutes of arc. Reinforced brass index arm, two horizon mirrors, three rectangular sun shades, one round horizon shade and a peep hole. The ivory plate on the crossbar inscription reads "SPENCER, BARRETT & CO LONDON."

It is fitted into the original keystone box made of oak, complete with the original key lock with inlaid brass key escutcheons along with hook and eye closure. The box measures 13 3/4 inches long (center of arch) by 12 inches wide and 4 inches thick. Missing a section of the upper right hand front corner of top, and the same on bottom. Sunbleached oak patina.

OCTANT MEASUREMENTS:m radius: 9 3/4 in; 24.765 cm overall: 12 in x 9 7/8 in x 3 3/16 in.

From the Edward L. Greenwood Maritime Collection