Civil War Field Glasses from Military Dealer Schuyler Hartley Graham NY

You are bidding on a very rare set of Civil War field glasses sold by the largest Military dealer of the period, Schuyler, Hartley, and Graham of New York. Their markings appear on both eye cups. They advertised such field glasses in their 1864 illustrated catalog. The glasses are in very good condition and are about 5" long in the closed position., They will extend and focus. The mechanism is a little stiff from age but functional. The thumb wheel actually looks to be made of brass instead of gutta percha. I think that is an indicator of older manufacture. If you collect Civil War antique optics, this is about as rare as the come.