Lot of 90 7.25x7.5x3.75" wide pairs of stereoscope views, each individually numbered w/titles on fronts and extensive text on backs. Keystone View Company, 1920. Made to be viewed w/a stereoscope, creating three-dimensional effect. Lot contains cards showing troops training, marching, in the trenches, etc., submarines and ships, zeppelins, tanks, large guns, war leaders, destruction w/bodies and much more. As typical, cards show warping plus scattered aging, dust soiling, handling wear and some scattered moistures staining. VG to VF overall. Interesting group showing the scope of this monumental war.