Folding-arm brass protractor by Troughton & Simms, London, in wooden case, mid 19th century. Folding-arm brass protractor by Troughton & Simms 1840-1860
Circular brass protractor, vernier arm with pricking extension, engraved "W & S Jones, 30 Holborn London", with glass centre piece, in box, B1754 Circular brass protractor 1800-1860
Circular protractor by Edward Troughton, London, 9 inch with folding arms, divided on silver to 1/3 degree reading by vernier to 1-inch, engraved "Troughton, London" & "F^O 40", in case Circular protractor by Edward Troughton
Circular protractor with two arms by George Adams, brass, in mahogany case (lid veneer lacking) Circular protractor with two arms by George Adams
Folding arm protractor, 6 inch; brass, divided in half degrees on silver, reading by vernier to one minute of arc. Distance between points about 12 inches Folding arm protractor 1876