IT is a battle of the astronomers, this question of Mars. Also it is complicated by the further fact that the slightest hint from the eyepiece of the telescope has set thoughtful men at work upon the enticing problem of life in other worlds than ours. Given the 'suggestion fancy. may be counted on to fly. Mr. Wells and his school have accepted the man of Mars, and a fine mess they have made of him. Mr. Tesla either has caught an etheric signal from the red planet or else he's going to catch one sometime, or else he knows how to go about it when he finds the time. The plains of Texas are to be vitrified with a mirror costing all of $10,000,000 in order to establish a signal service communication as soon as that branch of our military intelligence gets through with airship- ping. An astronomer is or was to go up in a balloon into the ultimate zero of the cold. of space equipped with tanks of air and machinery to pump it into his system, and there he was to bombard our neighbor with Hertzian waves. Finest triumph of all this genius, the picture has been drawn of the man on Mars. He has been assumed to be ffions of ages in, advance of our culture and in that time he has advanced to accord. with conditions we know not of. Certainly he is not a handsome object, but perhaps in the Martian pure intelligence mere comeliness is negligible. But all these flights of fancy can have no foundation in demonstrable fact other than such as is visible through the. instruments of astronomical observation. Thus it resolves itself down to a battle of the astronomers. The great superior planets lie too far away from the sun, their day and their year so widely vary from our own conditions, the spectroscope tells such tales of their heat conditions, that it is impossible to form any conception of life upon their surfaces. It is only Mars, our next outer neighbor in the solar system, and Venus, next within our orbit toward the sun, which offer conditions of night and day and the changes of seasons at all comparable with those familiar to us. Venus comes nearer to us than any of the heavenly bodies except our own satellite, so near at times as to be visible in broad daylight. But the conditions of illuminatidn are so baffling as to preclude the obtaining of any familiarity with the surface conditions which may exist upon so much of the Venus disk as ever comes into view. Mars, however, though never at its nearest so near as Venus, offers conditions of better visibility. It is not only when shepherds watched their flocks by night that the great. red star has challenged the attention of men. Even in the culture of the Middle Ages, by no means so wholly unenlightened as it is habit to think, the influence of Mars was potent upon the affairs of men; brave leaders suffered no lack of courage for knowing Mars prevailed in the house of their ascendant with the wealth of astrology to preach the moral. In the nights of these years of grace when one would wish to assume that centuries of education might have produced an instinct of sense Mars still smites the eye and the curious seek to be advised if Mr. Edison really has invented a star. Thus from the god of war to an electrician; verily the world remains utilitarian albeit the utilities vary in their relative importance. In September of this year Mars was in opposition at its orbital point of greatest proximity to the earth, a d1stance of 36,000,000 miles. Year by year its distance at opposition increases until it is 60,000,000 miles away. Not for fifteen years will it come so close as this year. Let us see what difference this makes in the thing seen. The telescopes of high power present the image of Mars as a disk in the same fashion that we see the disk of the moon at” full. At the nearest opposition the disk of Mars subtends an angle of twenty-five seconds of are, when the planet is at its farthest its disk is but four seconds. At its best it is more than six times as great as when it is at its farthest. Feet and inches have become f^iliar terms of measurement, not so the terms of angular measure. One needs, therefore, some comparison which may set a general meaning in this statement of the size of the Martian disk. A disk subtending an angle of twenty-five seconds of arc is smaller than a dime, only a little larger than the head of one's lead pencil. This is Mars when at its greatest in the eyepiece of the few really great telescopes. In a surface which a dime would hide lies the whole possibility of any knowledge of Mars which we may acquire. For a moment compare with this the eight-inch disk on which the hemispheres of our familiar world are presented in the atlases and pause to figure out how much of the terrestrial physiography and the life of mankind could be figured out from an area as large as a soup plate. Then will come some sense of the fact that it must call for a lifetime spent in the study of the twenty-five-second disks coming so rarely. Photography has been brought into service, but it can render no more than a partial aid. Only a few of the markings of the disk of Mars are strong enough to imprint themselves upon the most sensitive plates that chemistry has been able to produce. It is only under the most exceptional conditions of visibility and actinic sensitiveness that photography has caught even a spidery record of a very few of the thin markings which are called canals. For the finer detail it is impossible to eliminate the human factor, the personal equation of the observer. It is his eye that must see the markings of the planet and it is his pencil that must make the record for later study. So long as the human factor plays so large a part, just so long will there be reason to doubt the accuracy of the record. The beginning of the Mars problem lay in the invention of the telescope. The planet was by far the most conspicuous of the heavenly bodies, at least its better visibility outweighed the greater brightness of Venus. It was the target for the first of telescopes— each improvement in the optical mechanics of the telescope maker has brought with it a new train of observations upon Mars. Venus, because it rarely gets far enough away from the sun glare when its disk presents itself in any phase that might yield results, has practically dropped back into the position of serving at its transits for the mere measurement of parallax, and therefore the establishment of the earth's distance from the sun. As far back as 1643 Fontana at Naples discovered spots 011 the disk of the planet, this being (he parent observation from. which has grown the whole family of the canals. With his poor instrument Fontana could scarcely believe the existence of the M;:trtian spots, yet in his announcement of the thing that he had discovered he noted his feeling that if spots were really visible and if, as they seemed, they changed in position from night to night it might be the planet was in rotation. It was not until 1666 at Bologna that Cassini found himself in possession of a better instrument which did establish the existence of the Martian spots which Fontana had seen. From his study of these spots, better to be described as general markings, Cassini in a month's time was able to announce the axial rotation of the planet within three minutes of the time now satisfactorily established, namely, 24 hours 37 minutes 23 seconds. The length of the year on Mars, the completion of its orbital movement about the sun, is 687 days. After Cassini the Martian markings became better known. Their permanence, in all except one important particular, gave data upon which to pursue some study of their nature. From the fact that the same general markings were found in the same part of the disk at the same hours of the Martian day, that the observations of the present reproduced with great fidelity drawings made at much earlier periods, it was not difficult to establish as fact that we were see-rug the surface of the planet itself and not merely a dense surrounding atmosphere such as seems to veil from our sight the real bodies of other planets. If the observed markings were due to the presence of clouds in the Martian atmosphere it would be inconceivable on any- theory of air circulation which we can imagine that for year after year the clouds should rest over the same spot and should preserve the same form despite the temperature changes which must attend the wide range of distance from the sun. For these and similar reasons the first idea was soon relinquished that we' were looking from above upon a cloud mantle over the planet. By consequence the idea arose that in the atmosphere of Mars, then assuming the existence of an atmosphere, fine weather reigned through all the sea sons, for it is readily inferential that the eastward progress of atmospheric cyclones over the earth, with. their almost continental blankets of cloud, must obscure to the Martian observer from time to time the greater configurations of our planetary mass. The absence of such - phenomena in the centuries of observation of the Martian disk argues the absence of water vapor in its atmosphere in anything like the proportion known in earth atmosphere. The next great step in the discovery of Mars was made at Milan in 1877 by Schiaparelli. He announced that in the markings of the Martian disk he had identified a number of straight lines traced from radiant points or areas. To these fine threads or scratches he gave the designation of canals. His first announcement was followed in succession by others; that the lines were subject to a regularity of appearance and disappearance; that at certain times a well-defined line became twinned by a second line in close parallelism; that the appearance and vanishing of the lines, and in particular the twinning process, was governed by the waxing and waning of the Martian seasons. It has already been remarked that there is one important exception to the observed permanence of the markings of the disk of Mars. This concerns itself with two bright spots which of4jOupy varying areas at the two poles of the planet, and between them there is a fixed regularity in diversity, that as the northern spot of brightness enlarges its area its south polar companion contracts. The southern bright spot had been known for some sixty years whrpn Maraldi observed that it was subject to the most considerable variation in extent. It was not, however, until much later that the possession of a much greater equatorial telescope put it in the power of Sir William Herschel to observe similar phenomena at the northern extremity of the axis. When he was able to compare the synchronism with opposite signs of the two polar bright spots this distinguished astronomer was in the position to propound the theory that these localized brilliancies were due to seasonal changes in two ice caps such as are known to exist at the poles of the earth, despite its greater proximity to the sun. Schiaparelli made use of Herschel's discovery for the explanation of his own discovery of the Martian canals. In its simplest form his argument, now greatly expanded by Percival Lowell who has succeeded him in canal observations and has indeed greatly overpassed him, is that we do not see canals as water carrying bodies in themselves, but that we are justified in inferring their existence from what we really do see, a vital point upon which observational astronomers are by no means in hearty accord, namely, weas of vegetation. Taking as proved that there exist ice masses at the poles, it is assumed that the canals are great conduits extending to the melting face of the ice caps, drawing water toward the rainless equatorial regions, that laterals carry this water to such distance on either side of the main ditches as is found economical, that with the coming of the ice cap thaw the water reaches arable soil, and in no long time the result becomes visible to us when we look upon these narrow belts of fertility. Prof. Simon Newcomb, in opposing the theory of the visibility of mere canals, has pointed out that the minimum width which would become visible to us as a spiderweb line on the Martian surface cannot be less than sixty miles. As soon as these theories had been formulated and had been popularized outside of the Astronomische Nachrichten, the ultimate record of all that is new in astronomical discovery, it became at once apparent that this involved the argument of design. The argument of design predicates the existence of a directing intelligence. At once the question of life on Mars offered itself to the study of astronomy and theology. It has raged for a generation and is no nearer solution than it was at the beginning. Theological orthodoxy has settled the question in the negative. Very properly is this settlement made, for nowhere in revelation is there any provision for savable or damnable life upon any tributary planet of a geocentric universe. It is not the first debatable point of the cosmic physics which theology has determined. Such determinations have hitherto proved negligible. Therefore in this case the determination has nothing to do with the main facts at issue. The astronomical argument, involving conscious intelligences only as incidents, is more systematically fought out, and the solution is not yet in sight. Schiaparelli and Lowell after him have argued that the regularity of the fine lines in the - distribution of their irregular arrangemelt is inconceivable except upon the hypothesis of govocning design for the attainment of some rational end. The opposition presents a large mass of statistics of the cracks upon the moon and makes a stout showing that surface rupture of a planetary body may produce such ramification as appears in the markings of Mars either in the final stages of the loss of its ^ner heat or after the death of the planet by reason of the ultimate chill of zero space temperatures, the two periods being concurrent in the working for ages in proportion to the planetary mass. The proponents of the lunar hypothesis make out the case for the absence of the element of design. The adherents of the theory of Martian canaliculation for purposes of crop irrigation, which involves intensively the acceptance of- the theory of beings possessed of the higher intelligence which alone can combat the deficiencies of natural conditions, argue in reply that the lunar cracks lack all resemblance to the Martian markings, and that whatever may have happened to a dying and now dead world has no bearing upon a planet still living, even though it may have advanced to greater age than we shall have to contend with in terrestrial conditions for several million years or ages to come. The argument that Mars is still a living planet is for the present to rest on its possession of such a sufficiency of aqueous vapor as to admit of the support of living organisms of such cell structure as we may comprehend as living, although the arrangement and above all the specialization of the component life cells may not necessarily bear much resemblance to the observed balance of functions in our own bodies. The proponents of the canal theory of Mars acknowledged that the planet of their enthusiastic study is imperfectly watered, that except at the rim of the two melting snowcaps it offers conditions of aridity under which we mortals of earth could not maintain life at all. But they claim that under Martian conditions the force of evolution has produced a race of such higher intelligence as to compass a network of irrigation machinery such that, drawing alternately from the ice cap of the north and that of the south, it has been possible to produce harvests in the temperate regions of the Martian equator. In this argument the assumption lies in the two ice caps. The earth, its atmosphere of great richness in aqueous vapor and at a tension where precipitation is frequently possible over wide areas, certainly has ice caps. The opponents of Schiaparelli and Lowell deny the Martian ice caps. Mars has spots of polar which wax and wane with close and very rapid correspondence with the change in the angle of incidence of the sun's rays thereupon. It is argued that if the Martian atmosphere was so rich in aqueous vapor as to form these vast polar areas of ice it would be so rich that, under any comprehensible theory of convection and atmospheric circulation, it would be impossible for it to be so arid in its equatorial and midway regions as to call for any system of irrigation at all. Furthermore, in opposition to the canal theory, it is held that if it really be ice at the polar caps, and knowing as we do the number of thermal units effective when. the sun returns to shine upon each cap after its winter night, we cannot account for the rapidity with which the cap disappears in the sunlight. It vanishes with such speed that some observers have spoken of it as almost an evaporation, some such process as in the physics of the terrestrial atmosphere is observable in the warm Chinook winds of our northern Rocky Mountains, where whole fields of snow vanish as if dried up, the same phenomenon on the European Continent being equally familiar as the foehn of the Alps. So rapid is this disappearance of the bright spots in the circumpolar region when the sun dawns upon it that it is too rapid even to admit of the inference that it is only snow. It is said that nothing but hoar frost will at all answer the conditions observed. If the Martian atmosphere has so little vapor of water that its maximum polar deposits amount to no more than frost it is clear that the evaporation constant must be so high that no canal could possibly carry the collection of drops from a region of melting rime as far as the equator of a planet as great as our own or beyond the equator into the cold atmosphere as the theoretical conditions demand. This dilemma may thus be stated. If the water vapor in the Martian atmosphere is sufficient in amount to yield an ice cap at the polar bright spots the tension over the rest the planet must be such that canals will not be needed because of a sufficient precipitation; if the water vapor content is so slight that the polar caps are nothing but frost, no amount of engineering skill could cope with the tension which would evaporate whatever water may have started in the canals. Under terrestrial” conditions these two extremes are well represented by the Hudson, which never runs dry, and those rivers of the arid West which are greatest at the source and dwindle on their course until they end in a damp spot with bone dry edges. Before our philosophy can make much headway in the dicussion of the Martian intelligence it will be necessary to arrive at some solution of this critical question, What is the amount of the water vapor in the atmosphere of the red planet? Fortunately we are not. without appliances which may deal with this fundamental problem. The spectroscope yields a record of the constituents of~every sort of light which it dissolves, and the bands corresponding to water vapor have all been plotted on the spectrum. If these bands show at all, it is irrefragable evidence of the presence of water vapor, and in like manner the pronouncement of their definition gives a measure of the amount of such water vapor. If then comparative observations are made simultaneously of an illuminated object whose water vapor content is well established and of Mars, in which it is yet to establish that factor, the comparison of the bands in the two spectra will give a measure of the result in Mars. At the very favorable opposition in September the whole resource of the Lick Observatory staff was devoted to the making- of this comparison. In order to avoid as much as possible of the water vapor content of the earth's atmosphere, greatest in the lower levels, the observing station was equipped on the summit of Mount Whitney in the Sierras at the elevation of 14,501 feet and in a horizon markedly arid. Co-ordinately with the astronomical observations, physical measurements were made of the exact amount of water. vapor there present in the air. For purposes of the astronomical comparison the moon was taken as the standard. A long series of eclipse observations has shown that whatever atmosphere may persist about our satellite is optically indiscernible. Similar series of spectroscopic observations have shown that the water vapor at the moon is wholly inappreciable by the most delicate tests. Ii' the spectrum of Martian light photographed under the same terrestrial condition shows no more water vapor bands than appear in the photographed spectrum of lunar light the conclusion is warrantable that water vapor on Mars is of such extreme tenuity as not to be made available for cultural purposes. The complete results of the Mount Whitney observations have not yet been worked out, but Director Campbell authorizes the preliminary report that the comparison of simultaneous Martian and' lunar spectra proves that Mars has no more water about it than has the moon. He is concerned in the determination of this one fact in physics. The rest follows in its train of inexorable logic. If Mars has no more water- than the moon the polar bright areas cannot be ice, snow or hoarfrost; the most reasonable suggestion is that they are solidified carbon dioxide, the heaviest constituent of an atmosphere and the longest to linger over a dead world, itself a mantle of death and the shroud of animal life.—The New York Sun.
This article was originally published with the title "The Red God of the Sky"