Compass Of Artillery Or Caliber By Dean, Circa 1730

Compass of artillery or caliber signed "W. Dean Fecit". William Dean was active in London from 1718 to 1748. He was apprenticed to John Rowley. The compass consists of two branches connected by a pivot. The branches are fitted at their end with steel points fixed at right angles. On one side, the compass is engraved with a scale of proportion compasses (L for lines). Different tables give the quantity of powder to be placed in iron or brass guns for trial or combat shots. On the circular head, a scale with an index in the shape of a hand which indicates the weight of the iron ball when the points grip the diameter of these balls. The numbers engraved in the geometric figures correspond to the weight of these supposed solids of iron and a side foot. On the other side scales of English feet, equal parts. Etc. Very good condition for this artillery gun technique of early manufacture. Closed size: 17.5 cm long and 4.8 cm wide.