Electro astronomical atlas ... with explanatory notes, questions and answers
An astronomical teaching atlas by J. W. Spoor, printed in Albany, New York by Weed, Parsons and Company in 1874, pairing numbered plates with explanatory notes and question-and-answer drills for classroom use. The plates are white-line diagrams reversed out of dark grounds: the earth's orbit ringed with zodiac signs and month names, solstice and equinox positions, axis-inclination globes, and rows of graded discs comparing planetary sizes, giving designers stark negative-space circles, hatched shading and curved lettering.
