Chart of the moon.
Craters—
| 1 Tycho. | 2 Copernicus. | 3 Kepler. | 4 Aristarchus. |
| 5 Eratosthenes. | 6 Archimedes. | 7 Plato. | 8 Eudoxus. |
| 9 Aristotle. | 10 Petavius. | 11 Ptolemy. |
Grey plains formerly believed to be seas—
| A Mare Crisium. | O Mare Imbrium. |
| C —— Frigoris. | Q Oceanus Procellarum. |
| G —— Tranquillitatis. | X Mare Fœcunditatis. |
| H —— Serenitatis. | T —— Humorum. |
By studying this map, and the pictures, they were able, even in their small telescopes, to recognise Tycho and Copernicus, and the mountains of the moon, after they had once grown accustomed to the strange changes in their appearance which take place as daylight or darkness creeps over them. They could not however pick out more than some of the chief points. Only the magician himself knew every crater and ridge under all its varying lights, and now, as he waited for the eclipse to begin, he turned to a lad who stood behind him, almost hidden in the dark shadow—the one fortunate boy who had earned the right to share this night's work.
Fig. 3a.
The full moon. (From Ball's Starland.)