Twentieth century hand-book for steam engineers and electricians with questions and answers; a practical non-technical treatise .. (1913)
Swingle, Calvin Franklin, 1846- [from old catalog] · Chicago, F. J. Drake & company · leaf 526
Fig. 199 obtained. It showed the valve adjustment to be verynearly correct, but the perfectly straight steam lines, andthe sharp corners and sudden drop at cut off were a puzzle,especially in an old engine where the valves and valve seats … Fig. 200 were known to be much worn down. After taking severalmore diagrams with precisely the same result, the indicatorwas removed, and upon taking out the piston a quantity ofdirt was found on it, and also on the inside of the cylinder.This fully explained the cause of the sharp corners, etc.,…
