Page:The Music of the Spheres.djvu/329

 remarkable way over mountains, pits and plains. So numerous are these bright rays about the brilliant crater of Tycho that at full moon they may even be located as a patch of light to the unaided eye, although an opera-glass, which brings the moon down to 120,000 miles instead of 240,000, greatly improves the seeing. William H. Pickering, in his book on "Mars," gives some of the latest information concerning Tycho:

The moon is considered to be a matured globe, evolutionally old, and it has even been referred to as being nearly dead. Lacking, air, water, life and even the diversion of sound, it surely is at least in but a semi-conscious stage, as worlds go. Mars is also called an old world, but Mars has air, its snow-caps melt in sheets of water, and we view the colors which mark its seasons, across a distance of 50,000,000 miles. The moon looks as it is, seared and old. There have been many theories advanced to explain the abundance of its craters and their peculiar construction, but some modified form of the volcanic action is the only tenable one. No one theory has as yet met with universal approval.

A great telescope with a 100-inch lens has lately been erected at Mount Wilson, near Pasadena, California. The telescopes which have mirrors, like this one, are called reflecting telescopes. The largest reflecting telescope before the one now mounted on Mount Wilson became available, was the splendid instrument at