It is easy to photograph the sun, and this has been done. When we come to the moon the operation is more difficult on account of the feeble intensity of its light, and the difference of tint of the various parts of its surface. Skill and perseverance have, however, surmounted the greatest difficulties, and now we have photographs of the moon enlarged to more than a yard in diameter, which show the smallest details with a truly admirable clearness. In the first second of time, your eye receives as much light from the star as does the photographic plate in the same time. But during the course of one hour, the plate receives and stores up about thirty-six hundred times as much light as it or you received in the first instant. There is the secret of the matter. The photographic plate does not only receive, it can also keep and treasure up the light, and that our eyes are not able to do. If you magnify the amount received in one hour by five or ten, and remember that it is all retained, then you will begin to understand how feeble stars, unseen by man, should become known to us through photography. CHAPTER XXXII. THE DAWN OF ASTRONOMY. The beginnings of astronomy lie in the distance of earliest historical ages. It is no easy matter to say when first, in all probability, this science grew into existence. Astronomy was alive before the British nation was heard of; before Saxons or Franks had sprung into being; before the Roman Empire extended its iron rule; before the Grecian Empire began to flourish; before the Persian Empire gained power; before the yet earlier Assyrian Empire held sway. Among the ancient Chaldeans were devoted star-gazers--much more devoted than the ordinary run of educated Anglo-Saxons in this present century. They earnestly sought, in the dim light of those ages, to decipher the meaning of heaven’s countless lamps. We have better instruments, and more practiced modes of reasoning; also, we have the collected piles of knowledge built up by our forefathers through tens of centuries. Yet our search is in essence the same as was theirs, to know the truth about the stars: not merely to start some attractive theory, and then to prove that our theory must be right, because we have been so clever as to start it; but to discover that which is in those regions of space. No lower aim than this is worthy to be called scientific.