A Field Gunnery Calculating Slide Rule for use with the 18 Pounder Q.F. Gun.

摘要

108,172. Stokes, G. D. C. July 17, 1916. Slide-rules for use in field gunnery are provided with logarithmic scales for calculating range corrections for temperature, headwind, and barometer, and for computing ranges and angles from the formula tan C = c/b Î Sin E / 1+ 1/10 Cos. E, where E is the exterior angle at the apex A in the triangle A B C, A being the observer's post, B the battery position, and C the target. Formulµ are given for the scales for corrector change and range corrections for wind, barometer &c. The centre of the rule is flexible to improve the movement of the slides, and the top edge of the rule is provided with a map scale.