Page:The Music of the Spheres.djvu/65

 ing. Here is a slanting granite wall in which two eyeholes had been bored for the sole purpose of sighting Thuban.

Changes in the universe are very gradual and although 4000 years seems a long time to the limited mind of a human being, it is but little in comparison to the vast periods of time which must pass before a visible change can be noticed in the heavens. We speak of these years nonchalantly, but astronomers have had to work hard and patiently in order to make such assertions and to back them up with sufficient proof.

Traveling backward in imagination on the circle that our pole has taken 25,000 years to describe in the sky, and again imagining the star which we now see as our Pole Star as the Pole Star of that by-gone era, what a difference we find in the appearance of the earth! Herds of strange and savage animals are scattered here instead of thriving villages and cities, and man, in equally savage state, wanders about the hills and plains alone or in straggling bands. In traveling forward 21,000 years again to the time only 4000 years ago when Thuban, on the coils of the Dragon, shone as our Pole Star, we come to comparatively recent times; civilization on our earth has made great advances, not the least of them being that it has raised its head and has noted that there are not only stars but that the stars differ from one another. Probably during this era the Chinese chose the Dragon for their national emblem.

The principal interest in the constellation of Draco is, of course, the star Thuban. It is interesting to locate this ancient