In the last paper we saw how badly off for water Mars, to all appearance, is; so badly off that any inhabitants of that other world would have to irrigate to live. As to the actual presence there of such folk, the broad physical characteristics of the planet have nothing to say beyond a general expression of acquiescence, but they do have something very vital to say about the conditions under which alone their life could be led. They show that in these Martian minds there would be one question paramount to all the local labor, women's suffrage, and Eastern questions put together, the water question. How to procure water enough to support life would be the great communal problem of the day.
If Mars were the earth, we might well despair of detecting signs of any Martians for some time yet. Across the gulf of space that separates us from Mars, an area thirty miles wide would just be perceptible as a dot. It would, in such case, be hopeless to look for evidence of folk. Anything like London or New York, or even Chicago in anticipation, would be too small to be seen. So sorry a figure does man cut upon the earth he thinks to own. From the standpoint of forty millions of miles distance, probably the only sign of his presence here would be such semi-artificialities as the great grain-fields of the West when their geometric patches turned with the changing seasons from ochre to green, and then from green to gold. By his crops we should know him, a telltale fact of importance because probably the more so on Mars.
For Mars is not the earth. Conditions hold there which would necessitate a different state of things, inorganic and organic, apparently a much more artificial one. If cultivation there be, it must be cultivation upon a much more systematic scale, due in large part to a system of irrigation; just as any Martians must be quite different physically from men. Now, at this point in our investigation, when the broad features of Mars disclose conditions which imply irrigation as their organic corollary, we are suddenly confronted on the planets face with phenomena so startlingly suggestive of this very thing as to seem the uncanny realization of the deduction. Indeed, so amazingly lifelike is their appearance that, had we possessed our present knowledge of the planets physical condition before, we might almost have predicted what we see as criterion of the presence of living beings. What confronts us is this: —
When the great continental areas, the reddish-ochre portions of the disc, are attentively examined in sufficiently steady air, their desert-like ground is seen to be traversed by a network of fine, straight dark lines. The lines start from points on the coast, of the blue-green regions, commonly well marked bays, and proceed direct to other equally well-marked points in the middle of the continent. At these latter termini the lines meet, very surprisingly, other lines that have come there from different starting-points in a similarly definite manner. And this state of things exists all over the reddish ochre regions.
All the lines, with the exception of a few that are curved in a regular manner, are absolutely straight from one end to the other. They are arcs of great circles, taking the shortest distance between their termini. The lines are as fine as they are straight. As a rule, they are of scarcely any perceptible breadth, seeming on the average to be less than a Martian degree, or between twenty and thirty miles, wide. Some are broader; some even finer, possibly not above fifteen miles across. Their length, not their breadth, renders them visible; for though at such a distance we could not distinguish a dot less than about thirty miles in diameter, we could see a line of much less breadth, because of its length. Speaking generally, however, the lines are all of comparable width.
Still greater uniformity is observable in the different parts of the same line; for each line maintains its individual width throughout. Although at and near the point where it leaves the dark regions, or the Solis Lacus, for the same phenomenon appears there, some slight enlargement seems to take place, after it has fairly started on its course it remains substantially of the same size from one end to the other. As to whether the lines are even on their edges or not, I should not like to say, but the better they are seen, the more even they look. It is not possible to affirm positively on the point, as they are practically nearer one dimension than two.
On the other hand, their length is usually great, and in some cases enormous. A thousand or fifteen hundred miles may be considered about the average. The Ganges, for example, which is not a long one as Martian canals go, is about 1450 miles in length. The Brontes, one of the newly discovered, radiating from the Gulf of the Titans, extends over 2400 miles. Among really long ones, the Eumenides, with its continuation the Orcus, the two being in truth one line, runs 3540 miles from the point where it leaves the Phoenix Lake to the point where it enters the Trivium Charontis; throughout this great distance, nearly equal to a diameter of the planet, deviating neither to the right nor to the left from the great circle upon which it set out. On the other hand, the shortest line is the Nectar, which is only about 250 miles in length; sweetness being, according to Schiaparelli its christener, as short-lived on Mars as elsewhere.
That with very few exceptions the lines all follow arcs of great circles is proved: first, by the fact that when near the centre of the disc they show as straight lines; second, that when seen toward its edges they appear curved, in keeping with the curvature of a spherical surface viewed obliquely; third, that when the several parts of some of the longer lines are plotted upon a globe they turn out to lie in one great circle. Apparent straightness throughout is only possible in short lines. For a very long arc upon the surface of a revolving globe tilted toward the observer to appear straight in its entirety it must lie in certain positions. It so chances that these conditions are fulfilled by the canal called the Titan. The Titan starts from the Gulf of the Titans, in south latitude 20~, and runs due north almost exactly upon the 169th meridian for an immense distance. I have followed it over 2300 miles down the disc to about 430 north, as far as the tilt of the planets axis would permit. As the rotation of the planet swings it round, it passes the central meridian of the disc simultaneously throughout its length, and at that moment comes out strikingly straight, a substantialized meridian itself.
Although each line is the arc of a great circle, the direction taken by this great circle may be any whatsoever. The Titan, as we have seen, runs nearly due north and south. Certain canals crossing this run, on the contrary, almost due east and west. There are others, again, belting the disc at well-nigh every angle between the two. Nor is there any preponderance, apparently, for one direction as against any other. This indifference to direction is important as showing that the rotation of the planet has no direct effect upon the inclination of the canals.
But, singular as each line looks to be by itself, it is the systematic network of the whole that is most amazing. Each line not only goes with wonderful directness from one point to another, but at this latter spot it contrives to meet, exactly, another line which has come with like directness from quite a different starting-point. Nor do two only manage thus to rendezvous. Three, four, five, and even seven will similarly fall in on the same spot, a sociability which, to a greater or less extent, takes place all over the surface of the planet. The disc is simply a network of such intersections. Sometimes a canal goes only from one intersection to another; more commonly it starts with right of continuation, and, after reaching the first rendezvous, goes on in unchanged course to several more.
The result is that the whole of the great reddish-ochre portions of the planet is cut up into a series of spherical triangles of all possible sizes and shapes. What their number may be lies quite beyond the possibility of count at present; for the better our own air, the more of them are visible. About four times as many as are down on Schiaparelli's chart of the same regions have been seen at Flagstaff. But before proceeding further with a description of these Martian phenomena, the history of their discovery deserves to be sketched, since it is as strange as the canals themselves.
The first hint the world had of their existence was when Schiaparelli saw some of the lines in 1877, now eighteen years ago. The world, however, was anything but prepared for the revelation, and, when he announced what he had seen, promptly proceeded to disbelieve him. Schiaparelli had the misfortune to be ahead of his times, and the yet greater misfortune to remain so; for not only did no one else see the lines at that opposition, but no one else succeeded in doing so at subsequent ones. For many years fate allowed Schiaparelli to have them all to himself, a confidence he amply repaid. While others doubted, he ~vent from discovery to discovery. What he had seen in 1877 was not so very startling in view of what he afterward saw. His first observations might well have been of simple estuaries, long natural creeks running up into the continents, and so cutting them in two. His later observations were too peculiar to be explained even by so improbable a configuration of the Martian surface. In 1879, the canali, as he called them (channels, or canals, the word may be translated, and it is in the latter sense that he now regards them), showed straighter and narrower than they had in 1877: this not in consequence of any change in them, but from his own improved faculty of detection; for what the eye has once seen it can always see better a second time. As he gazed they appeared straighter, and he made out more.