JF Ptak Science Books Quick Post
This interesting and arresting images appears in Scientific American Supplement, October 23, 1915 (page 269). It is an excellent view of topside from 30′ or so below. The article describes simple, compound, tele-objective, direct-reflected, panoramic, and periscopes with annular fields–sort of simple, but not really. In any event the panoramic periscope gave a view of a directed point-of-view as well as a slender (but versatile) 360o.