The above quotations indicate that even now an alarm is felt in countries of fair rainfall regarding the possible failure of the water supply in the near future and is perhaps a premonition as to what may be absorbing our energies in centuries to come. Such possibilities as here suggested may offer an additional clew to an interpretation of the Martian markings.
The unnatural straightness of these interlacing lines on Mars, many of them following the arcs of great circles, their uniform width throughout, their always starting from definite areas, their convergence to common centres, and their varying visibility synchronizing with the Martian seasons finds no parallel in natural phenomena.
If in the mind's eye we were to survey the Earth from Mars the only feature we should find at all paralleling the lines in Mars would be found in the level regions of the West, where, for thousands of miles, the land extends in vast level stretches. In these regions would be found lines of railroads running in straight courses, starting from definite places, converging to common centres, their sides, in certain seasons, conspicuous with ripening grain fields, or again the work of the United States Reclamation Bureau running its irrigating canals in various directions through that great region. Both these kinds of lines would be artificial and both designed for purposes of conveyance—in the one case, merchandise and passengers, in the other case, water.
If the Martian lines are not artificial some other theories must be offered than those thus far advanced to explain their origin and purpose.
The phenomenon of the extraordinary doubling of the canals when first announced was immediately disbelieved; when, however, other observers confirmed Schiaparelli's discoveries, and it became evident that these double lines had a veritable existence, the phenomenon was regarded as an evidence that profound physical changes were going on in the planet. Thus in 1887 Mr. Stanislaus Maunier, in "La Nature,"[6] in alluding to the remarkable discovery of the doubling of the canals, says: "Mars at this moment is the theatre of phenomena of stupendous grandeur which will be adequate in a few years to impress profound changes in its aspect." This was written in 1887, and continuous observations of the planet since that time have shown no profound changes, or changes of any kind beyond those which periodically occur with the seasons. Since Mars is a much older planet than the Earth, it seems reasonable to believe that it is more stable, that volcanoes and earthquakes have long ceased to manifest their activities, that erosive action by water is no longer in evidence, subsidence and elevation of continental areas no longer occur. From this condition of the planet it is impossible to believe that the curious phenomenon of the doubling or gemination of the canals can be due to any physical changes now taking place.
Schiaparelli said that many of the ingenious suppositions advanced to account for this doubling of the canals would not have been proposed had their authors been able to examine the gemination with their own eyes; he further says: "It is far easier to explain the gemination if we are willing to introduce the forces pertaining to organic nature; here the field of plausible supposition is immense," and in this field of suppositions he suggests "changes of vegetation over vast areas." Let any intelligent mind soberly consider this rational suggestion of Schiaparelli's and compare it with other theories that have been advanced, and he will be compelled to admit that vegetation alone gives us at least a clew to the extraordinary behavior of these parallel lines. To understand the symmetry, the suddenness, and the vast extent of this phenomenon, the further explanation of vegetation superinduced by artificial methods will alone complete the answer.
Sir Robert Ball cannot conceive how Mars, a much older planet, should develop synchronously with the Earth creatures of intelligence, an event which he insists should have occurred ages earlier in its history. In this supposition he is quite right, for if there are creatures of intelligence in Mars these should have appeared much earlier, and that is probably what has happened. The problem is one parallel to that urged by Sir Boyd Dawkins in regard to the evidences of man in the Tertiary rocks. Dawkins argued that since the mammals in the Tertiary had changed so profoundly, many types becoming extinct, if man had lived at that time he also should have been affected by the same influences, and should have changed accordingly. It has been clearly pointed out by Cope and others that the moment intelligence became a factor in natural selection it was seized upon to the relative exclusion of physical characteristics, hence but little change, otherwise than an intellectual one, has taken place in man since his progenitors took to the trees and made up by agility, cunning, and alertness what they lacked in physical strength. In the same way, if, in the past history of Mars, an intelligent creature appeared he must have survived under precisely similar conditions, and long after favorable environments had passed that were implicated in making him what he was.
Admitting that there is an intelligent creature of some kind in Mars, is it reasonably conceivable that he should have caused such changes in the surface features of that planet as to be visible from the Earth? Professor Newcomb concludes, in a recent article in "Harper's Magazine," that "we cannot expect to see any signs of the works of inhabitants in Mars, if such exist." Let us, however, reverse the proposition and ask ourselves if man has been implicated in any changes in the surface appearance of the Earth that would be visible from Mars? And I think the question can be answered in only one way. The vast cities such as Pekin, Tokio, London, and New York, with their great expanse of tiled and slated roofs, and sterile streets, would certainly have a different albedo from the grass and trees in the immediate outskirts of such places. The tracts of land reclaimed from the sea, and still more the enormous areas which have been rendered green by irrigation, must, of all contrasts, be markedly conspicuous. To realize the extent of this work, it is only necessary to state that in Egypt 6,000,000 acres depend upon irrigation, and this area to be vastly increased in a short time; the Western states of America with 10,000,000 acres, and this area being rapidly augmented by the work of the United States Reclamation Bureau; in India 25,000,000 acres under irrigation, and this being continually added to; above all, however, the vast extent of territory from which the dark forests have been removed in this country, and more particularly in China, must make a visible landmark. If one can recall the appearance of forests in the southern and middle part of Maine, say from Bethel or Bangor, fifty years ago, he will remember that from the top of any hill a stretch of dark blue forest was to be seen as far as the eye could reach, and now from the same elevations one can see only an occasional clump of blue forest, while the remaining surface is, according to the season, either bright green, yellow with ripening vegetation, or white with snow, out of which the dark clumps of forest growth are most conspicuous. Considering the contrasting colors in one year covering hundreds of thousands of square miles in various portions of the country, the question naturally arises which of these contrasts would be most conspicuous,—the colors just mentioned of solid land surfaces of vegetation, snow, and desert, or diaphanous clouds with their gray shadows. We are told that Jupiter, with the mean distance at opposition of nearly 400,000,000 miles, shows its clouds, its red spot, and the shadow transits of its satellites. Surely if these conditions are seen from the Earth, the changes in the Earth's appearance above described might be seen from Mars, which at its nearest opposition is only 35,000,000 miles away, and, conversely, any change of similar character in Mars would certainly be visible from the Earth.