TOP QUALITY SEXTANT SIGNED ON THE ARC: J. PARKES & SONS. LIVERPOOL. No. K291. PATENT No. 15917. SILVER SCALE WITH 10' MINUTE DIVISIONS, VERNIER READING TO 10" SECONDS OF ARC. COMPRISING OF ERECT EYE-PIECE, HIGH & LOW INVERTING SCOPES, PATENT GREATEST ANGLE CLAMP, SCREWDRIVER & MIRROR ADJUSTMENT KEY. ALL THREE EYE-PIECES FIT THE UNIVERSAL OBJECT GLASS WITH RACK & PINION FOCUSING. ALTHOUGH NAMED PARKES THIS SEXTANT WAS MADE BY HEATH OF LONDON WITH IT'S FAMOUS BELL-FRAME.