How planets and moons were made
Lewis's 1915 cosmogony treatise, printed in Sacramento, California, for general readers interested in how planets and moons formed. The diagrams are plain line drawings of concentric rings, wave-like curves, a shaded body with a bulging crest, and a small orbiting sphere passing a larger one, giving designers clean schematic motifs of orbits, ripples and tidal forms in a restrained early-twentieth-century technical style.
