“3° = Medium gray (example, interior of Theophilus).
“4° = Yellowish gray (example, interior of Manilius).
“5° = Pure light gray (example, surface around Kepler).
“6° = Light whitish gray (example, walls of Macrobius).
“7° = Grayish white (example, Kepler).
“8° = Pure white (example, walls of Copernicus).
“9° = Glittering white (example, Proclus).
“10° = Dazzling white (sole example, the central peak of Aristarchus).”
“Really, I am greatly surprised by what you tell me,” said my friend. “I would never have imagined that there were so many different neutral tints on the moon.”
“You would be still more surprised,” I replied, “if I could present to you a similar table of the different tints of color that have been discovered there. But I am not aware that any scale of lunar colors has been prepared. There are, however, various shades of brown, yellow, and green. Most of them are found in the mares and walled inclosures. Some of them appear to be variable, and some are only to be detected under particular illuminations.”