“It is a thing to laugh at (perhaps) just at present. But when we consider the ratio of man’s advance in the last hundred years, what will it be in a billion? Not all the laws of the universe have been discovered, by any means. At present we know nothing. Who can tell?

“Aye, who can tell? Perhaps we ourselves have in store the fate we would mete out to another. We have a very dangerous neighbor close beside us. Mars is in dire straits for water. And we know there is life on Mars and intelligence! The very fact on its face proclaims it. The oceans have dried up; the only way they have of holding life is by bringing their water from the polar snow-caps. Their canals pronounce an advanced state of cooperative intelligence; there is life upon Mars and in an advanced stage of evolution.

“But how far advanced? It is a small planet, and consequently eons of ages in advance of the earth’s evolution. In the nature of things Mars cooled off quickly, and life was possible there while the earth was yet a gaseous mass. She has gone to her maturity and into her retrogression; she is approaching her end. She has had less time to produce intelligence than intelligence will have—in the end—upon the earth.

“How far has this intelligence progressed? That is the question. Nature is a slow worker. It took eons of ages to put life upon the earth; it took eons of more ages to make this life conscious. How far will it go? How far has it gone on Mars?”

That was as far the the comments went. The professor dropped his eyes to the rest of the paper. It was a map of the face of Mars, and across its center was a black cross scratched by the dull point of a soft pencil.

He knew the face of Mars. It was the Ascræus Lucus. The oasis at the juncture of a series of canals running much like the spokes of a wheel. The great Uranian and Alander Canals coming in at about right angles.

In two jumps the professor was in the observatory with the great lens swung to focus. It was the great moment out of his lifetime, and the strangest and most eager moment, perhaps, ever lived by any astronomer. His fingers fairly twitched with tension. There before his view was the full face of our Martian neighbor!

But was it? He gasped out a breath of startled exclamation. Was it Mars that he gazed at; the whole face, the whole thing had been changed before him.

Mars has ever been red. Viewed through the telescope it has had the most beautiful tinge imaginable, red ochre, the weird tinge of the desert in sunset. The color of enchantment and of hell!

For it is so. We know that for ages and ages the planet has been burning up; that life was possible only in the dry sea-bottoms and under irrigation. The rest, where the continents once were, was blazing desert. The redness, the beauty, the enchantment that we so admired was burning hell.