The sextant consists of circular black-lacquered brass plates with a hinged wooden handle. The two index arms are on the outside of the upper and lower plate, and separate milled knobs move them. The instrument has no shades. The glasses are contained in the instrument. Index glass adjustment is made with a single screw and on the horizon glass by a milled key shipped in the upper plate.

Attached to the sextant are two single lens magnifiers each on a 70mm swivelling arm. The telescope is 104 mm in length with an erect image and an eyepiece with three green shades. The lower plate can be removed for cleaning.

The instrument has two inlaid silver scales both from -5° to 180° by 30 arcminutes, measuring to 156° (the digits are read from the pivot). The sextant has two gold verniers measuring to 1 arcminute, with zeros at the left.

The sextant is contained in a fitted rectangular mahogany box, containing in the lid the certificate of the Halstead Science and Art Club Prize for an oil painting, awarded to E. T. Adams, 15 March 1911.

George’s double sextant could be used to measure two altitudes of the same or of two different celestial bodies in quick succession. This was useful when a body was visible only briefly, for example between flying clouds. According to Raper in 'The Practice of Navigation' it could also measure the angular distance between opposite points of the horizon, thus serving as a dip sector; with this example the range is limited to 156°. For this sextant, and for his artificial mercurial horizon (cat. no. 330) George (1809-87) received a medal at the International Geographical Congress of Paris, 1875.