75 mm Type 88 Anti-Aircraft Gun Brass Trajectory Quadrant

Brass quadrant for Japanese 75 mm Type 88 Anti-Aircraft Gun to compute elevation. This is one of two brass quadrants which are located on each side of the gun. It represents the elevation quadrant of the gun from 0 degrees to 90 degrees. The face of the plate is inscribed with two sets of curves, which are plotted in polar co-ordinates. Those curves on the elevation plate are plotted in quadrant elevation and superelevation for any given altitude, and are the means of applying superelevation to the gun. The curves are plotted for characteristics of one type of ammunition and fuze only, and must be changed for each type.

Markings: inscibed into the plate two sets of curved trajectory computations followed by numerals, on the outside edge of the quadrant are measurements from 0 to 90 degrees, quandrant serial No. "229". There are also many Japanese characters which translate roughly to "Type 88 7 cm Field Ant-Aircraft Trajectory Observation Chart, Type 90 Dispersion Ellipses, Shell - type 90 A/A pointed shell, Fuze - type 89 Pointed A/A Fuze, Weight - 6 kilos 54, Muzzle velocity - 720 meters/ per second".

This quadrant was apparently found in Wewak near Cape Worn. According to the donor the gunner at Wewak to which this quadrant belonged was refered to as 'Pistol Pete' by USAAF aircrew, as they indicated that he was rather accurate. Australian Forces refered to this position as 'dead eye dick'.