1942 Carl Lange Stereoscopic Opthomological "Coordinator" Slides - Set 5 glasses masks designed by Nils Thorsson

designed by Nils Thorsson

the text is super clear and readable

the other of a street of row houses--illustrating word problems

while pegs on the diamond below would indicate positions of base runners

including the division of each inch into eighths

1942 Carl Lange Stereoscopic Opthomological "Coordinator" Slides - Set 5 glasses masks designed by Nils ThorssonI was pretty excited to find a box full of these handmade slides at the flea market this weekend a box in which many were rolled up in newspaper from 1945, seemingly untouched since then! What I've learned is that Carl W. Lange Sr. and Jr. , who copyrighted this set of stereoscopic slides in 1942, were father and son opthomologists with a practice near St. Louis and a particular commitment to curing myopia (nearsightedness.) They wrote and travelled