Elementary optics and applications to fire control instruments (1922)
United States. Army. Ordnance Dept · Washington, Govt. Print. Off. · leaf 30
allelism is true, no matterhow the prism is turned so long asit receives the incident light. Useis made of this prism in signallingdevices and in the internal adjust-ment device of small range finders.The penta prism illustrated in fig-ure 27 is used in the range finder asan end reflecting prism.… … makes this prismuseful in range fin-ders. The anglesmeasured by therange finder are sosmall that if a con-stant deviationprism were notused the variationin the angles of de-viation at the endreflectors broughtabout by the flex-ure of the tube andconsequent rota-
Optics · Optical instruments · Fire control (Gunnery) -- Optical equipment
Internet Archive · California Digital Library · Public Domain Mark 1.0. Free to use for anything.
