Inaccurate performance data for BOB fighters in COD comparing to RL data

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In the interests of clarity, the following chart taken from Flight - December 2nd, 1943 is useful for comparing Schlaifer's manifold pressures, given in inches of mercury in his Development of Aircraft Engines depicted above, with the equivalent boost pressures in lbs/sq.in. as used by the British. Schlaifer wrote "Before the middle of 1940, a manifold pressure of 54.3 in. was authorized, giving a combat rating of 1,310 hp at 9,000 feet...". 54.3 in. Hg is the equivalent to +12 lbs/sq.in.. 1,310 hp at 9,000 feet operating at 54.3 in Hg. (+12 lbs /sq.in) is in agreement with the combat rating for the Merlin III given in Alec Harvey-Bailey's The Merlin in Perspective, pg 155.