“On the other hand, I think it quite probable,” said the professor, “that these people are much like ourselves, in size as well as formation. That they possess extraordinary intelligence I feel certain, for they are a far older race than our own, and their wits have doubtless been sharpened by their ceaseless combat with nature.”
“Then you believe that their unusual skill, and not physical strength, has enabled them to achieve these wonderful feats!”
“Not entirely. The force of gravity at the surface of Mars is approximately but three-eighths of that on the Earth. The result is that a being of our strength on Mars would be capable of about seven times as much work as on Earth. For example, he could dig a trench on Mars seven times as long as he could one of the same size on the Earth in the same length of time. The weight of the soil, of his arms and body, would be much less than on Earth, and the ratio of his strength over the reduced task would be augmented greatly.
“Then again, haunted, century after century, by the specter of extinction, the Martians would doubtless invent all manner of marvelous contrivances for the accomplishment of their gigantic tasks. Necessity has probably goaded them to a frenzy of invention and research.”
“Don’t you think it more likely that the ‘canals’ are really giant underground ducts! I should think long, open waterways would allow most of the water to evaporate before it had reached the ends,” said Taggert.
“I do. However, the popular conception of the word ‘canal,’ is that of an open waterway, whereas any duct, passage or groove, may properly be termed a canal.”
“But such canals or tubes would not be visible from the Earth, surely,” reasoned Taggert.
“Certainly not; but the vegetation which they fed would be. That is evidently why, with the melting of the polar caps, the lines have been observed to deepen in color with the season. I believe this indicates the quickening of the growths in the strips of irrigated ground along the ‘canals,’ the rate of progression observed being about fifty-one miles a day.”
“How do you account for that? Gravity could scarcely be responsible, for there would be no more reason to expect all water to run from the poles to the equator on Mars than to expect the same thing to happen on Earth.”
“Exactly. The Martians must have some unusual method of pumping the water through these canals.”