Laboratory astronomy
A 1905 astronomy laboratory manual by Robert Wheeler Willson, issued by Ginn & Company of Boston and New York for students doing practical exercises in observation and measurement. The engravings show celestial globes on cross-braced tripod stands, graduated meridian rings and horizon circles, gridded spheres labelled with star names and hour numerals, and spare line diagrams of hemispheres cut by a horizon plane; useful for latitude-longitude grids, scale rings, and instrument silhouettes.
