LIEUTENANT COLONEL DAVID MASON’S GUNNER’S PERPENDICULAR AND Circumstance, C. 1776 A gunner’s perpendicular, possibly produced in Massachusetts. : LIEUTENANT COLONEL DAVID MASON'S GUNNER'S PERPENDICULAR AND CASE, C. 1776 A gunner's perpendicular, perhaps manufactured in Massachusetts, courting to the 2nd half of the 18th century, engraved on the lower portion of https://ruhollahc701fvl5.wikififfi.com/user