Photo by David Friend Productions, San Diego, California
5 1/2" PATENT DOUBLE SEXTANT BY HENRY HUGHES & SON
05-005. English, 3rd quarter 19th century, signed in script "Henry Hughes and son, patent double sextant 3318, 59 Fenchurch Street, London." Made of black oxidized and polished lacquered brass, the 5 3/8" diameter circular frame carries the elements of two sextants - one to measure the angle to a second object left of the central object and one to measure the angle to a third object to the right. Two index mirrors are mounted one above the other at the center of the circle. Each mirror is rotated independently with its own index arm. Each index arm has a compound scale magnifier and a vernier that reads to 1 arcminute. Each index system has a scale of inlaid silver divided to 30 arcminutes and graduated from -5 degrees to +195 degrees. The original accessories include one sighting telescope, the mahogany handle, and an adjusting pin wrench; the second eyepiece and a solar filter are missing. This unusual double sextant is in very good overall condition, in its original 8 1/4" x 7 1/8" x 4' fitted mahogany case. See page 139 in Peter Ifland's "Taking the Stars" for a color photograph and description of a similar instrument in his collection.
