Manufactured by William W. Marston, New York City circa 1858 to 1864 with a total production of about 1,500, with 1,200 having the sliding knife blade, such as this particular example has. This particular deringer has the later production rounded or spear point blade found on only 400 of these deringers. The frame is decorated with scroll engraving and marked "Wm W. MARSTON / PATENTED / MAY 26, 1857 / NEW YORK CITY" and the matching serial number is marked on the left rear of the barrel and on the frame under the grips. The inside of the right grip panel is stamped with the matching number. Brass post front and frame notch rear sight, right side frame mounting firing indicator, the barrels and knife were blue and the brass frame was silver plated. The superposed barrels tip downward for loading. Fitted with smooth two piece varnished walnut grips.