And spoke of a hope for the world in the coming wars—
... and pointed to Mars
As he glow'd like a ruddy shield on the Lion's breast.'
Ancient records tell us of his brightness having been so great on some occasions as to create a panic. Panics were evidently more easily created by celestial phenomena then than they are now; but possibly such statements have to be taken with a small grain of salt.
The diameter of Mars is 4,200 miles. In volume he is equal to one-seventh of the world; but his density is somewhat smaller, so that nine globes such as Mars would be required to balance the earth. He turns upon his axis in twenty-four hours thirty-seven minutes, and as the inclination of the axis is not much different from that of our own world he will experience seasonal effects somewhat similar to the changes of our own seasons. The Martian seasons, however, will be considerably longer than ours, as the year of Mars occupies 687 days, and they will be further modified by the large variation which his distance from the sun undergoes in the course of his year—the difference between his greatest and least distances being no less than 26,500,000 miles.
The telescopic view of Mars at once reveals features of considerable interest. We are no longer presented with anything like the beautiful phases of Venus, though Mars does show a slight phase when his position makes a right angle with the sun and the earth. This phase, however, never amounts to more than a dull gibbosity, like that of the moon two or three days before or after full—the most uninteresting of phases. But the other details which are visible much more than atone for any deficiency in this respect. The brilliant ruddy star expands under telescopic power into a broad disc whose ground tint is a warm ochre. This tint is diversified in two ways. At the poles there are brilliant patches of white, larger or smaller according to the Martian season; while the whole surface of the remaining orange-tinted portion is broken up by patches and lines of a dark greenish-grey tone. The analogy with Arctic and Antarctic ice and snow-fields, and with terrestrial continents and seas, is at once and almost irresistibly suggested, although, as will be seen, there are strong reasons for not pressing it too far.
The dark markings, though by no means so sharply defined as the outlines of lunar objects, are yet evidently permanent features; at least this may be confidently affirmed of the more prominent among them. Some of these can be readily recognised on drawings dating from 200 years back, and have served to determine with very satisfactory accuracy the planet's rotation period. In accordance with the almost irresistible evidence which the telescope was held to present, these features were assumed to be seas, straits and bays, while the general ochre-tinted portion of the planet's surface was considered to be dry land. On this supposition the land area of Mars amounts to 5⁄7 of the planet's surface, water being confined to the remaining 2⁄7. But it is by no means to be taken as an accepted fact that the dark and light areas do represent water and land. One fact most embarrassing to those who hold this traditional view is that in the great wealth of detail which observation with the huge telescopes of to-day has accumulated the bulk belongs to the dark areas. Gradations of shade are seen constantly in them; delicate details are far more commonly to be observed upon them than upon the bright portions of the surface, and several of the 'canals' have been traced clear through the so-called seas. Speaking of his observations of Mars in 1894 with the 36-inch refractor of the Lick observatory, Professor Barnard says: 'Though much detail was shown on the bright "continental" regions, the greater amount was visible on the so-called "seas."... During these observations the impression seemed to force itself upon me that I was actually looking down from a great altitude upon just such a surface as that in which our observatory was placed. At these times there was no suggestion that the view was one of far-away seas and oceans, but exactly the reverse.' Such observations are somewhat disconcerting to the old belief, which, nevertheless, continues to maintain itself, though in somewhat modified form.
It is indeed difficult, if not impossible, to explain the observed facts with regard, for instance, to the white polar caps, on any other supposition than that of the existence of at least a considerable amount of water upon the planet. These caps are observed to be large after the Martian winter has passed over each particular hemisphere. As the season progresses, the polar cap diminishes, and has even been seen to melt away altogether. In one of the fine drawings by the Rev. T. E. R. Phillips, which illustrate this chapter (Plate [XX.]), the north polar snow will be seen accompanied by a dark circular line, concerning which the author of the sketch says: 'The melting cap is always girdled by a narrow and intensely dark line. This is not seen when the cap is forming.' It is hard to believe that this is anything else than the result of the melting of polar snows, and where there is melting snow there must be water. Such results as those obtained by Professor Pickering by photography point in the same direction. In one of his photographs the polar cap was shown much shrunken; in another, taken a few days later, it had very considerably increased in dimensions—as one would naturally conclude, from a fall of snow in the interval. The quantity of water may not be anything like so great as was at one time imagined; still, to give any evidence of its presence at all at a distance of 40,000,000 miles it must be very considerable, and must play an important part in the economy of the planet.