Part 4

The question naturally arises, if the water of Mars is piled up at the poles as snow, how does it find its way back on its melting? A discovery made by Schiaparelli in 1877 revealed the existence of various lines marking the surface which he called canali, or channels. These lines cover the face of the planet like a net, they are laid out with geodetic precision. "The lines start from points on the coast of the blue-green regions, commonly well-marked bays, and proceed directly to what seem centres in the middle of the continent, since, most surprisingly, they meet there other lines that have come to the same spot with apparently a like determinate intent." In other words these lines--fine, straight, dark, as if cut by an engraver, some of them running for hundreds of miles--converge at certain centres. They all start, as Schiaparelli first observed, from definite regions and terminate at definite points. Many of them follow the arcs of great circles. These lines may be thirty or more miles in width, apparently preserving the same width throughout, though slightly wider where they leave the dark bands. They run in every direction, a number often converging at a common centre, and, when they do so, a round, dark area appears which Lowell has called an oasis.

In the clear and steady atmosphere of Flagstaff, Mr. Lowell, by the aid of his superb telescope, has added about four times as many canals as are shown on Schiaparelli's chart. These canals form an intricate network of lines, and no one can contemplate these curious features without being impressed by their artificial character. Schiaparelli, who first discovered them in 1877, continued his observations from year to year despite the fact that no one else could see them. In the course of a few years he discovered a still more remarkable condition, and this was that a number of the canals appeared double. This, indeed, seemed an optical illusion, and by no means strengthened his position, as the single canals proclaimed by him were supposed to be figments of the imagination. Undeterred by the general scepticism, Schiaparelli established, at each fresh opposition, his previous announcements. For nine years no one was able to confirm his marvellous discoveries. In the year 1886, however, Perrotin, at Nice, with his assistant, Thollon, managed to make out a number of the canals, single and double, which were carefully drawn. Reference to Perrotin's work will be made further on. The reason why so few have seen them is the lack of observers with acute eyesight and patient devotion to the work, coupled with unsteady air. Size of aperture seems to be of little importance. That Schiaparelli, with an 8-1/3 inch glass, discovered the canals, while with the twenty-six inch glass of the Naval Observatory at Washington they have never been seen, is emphatic evidence of what a clear and steady atmosphere means in the study of delicate planetary markings.

The artificiality of the canals is shown by the "supernaturally regular appearance of the system, upon three distinct counts: first, the straightness of the lines; second, their individually uniform width; and, third, their systematic radiation from special points." It was the mathematical shape of the Ohio mounds that first suggested their artificial character. That these lines are artificial and not natural is seen in the fact that at times they are not visible. The lines while temporary in appearance are permanently in place. "Not only do they not change in position during one opposition; they seem not to do so from one opposition to another." "Unchangeable, apparently, in position, the canals are otherwise among the most changeable features of the Martian disk." The order of their appearance synchronizes with the changes of the season, as the snow caps begin to melt the canals begin to appear; in appearance strengthened first at the borders of the polar seas and gradually stretching down towards the equator. In minute detail Lowell presents the successive visibility of the different canals. To account for all these phenomena we have to look at our own Earth for a parallel, and we see it in the great irrigation tracks of the West, and in the vast irrigated regions in India depending upon the melting of the Himalaya snow cap.

The accumulative evidence is overwhelming that here is a dry planet, and an intelligence of some kind that can only survive by utilizing the few remaining sources of water supply. It is to the merit of Professor W. H. Pickering, to whom Professor Lowell gives the credit of having first suggested the idea of irrigation to account for the great width of the canals. What we see, then, is not the canal, which may be a slender stream of water, but a broad band of vegetation irrigated from these narrow channels. These lines penetrate and cross the dark regions in various directions, which again offer additional proof that the so-called seas are not seas but areas of vegetation sparsely scattered, against which the irrigated portions are of sufficient strength and color to show.

Among the most interesting features of the planet's surface are the round, or oval spots which Lowell calls oases; these invariably occur at the junction of the canals. "In spite of the great number of the spots, not one of them stands isolate. There is not a single instance of a spot that is not connected by a canal to the rest of the dark areas." There appears to be no spot that has not two or more canals running to it, and apparently no canal junction is without its spot. The majority of the spots are 120 to 150 miles in diameter. There are many smaller ones. These spots, like the canals, appear and disappear coincidently with seasonal changes. The canals and the oases follow the same method and order in their growth. "Both are affected by one progressive change that sweeps over the face of the planet from the pole to the equator." The reader cannot dwell too strongly on the fact that the visibility of these various markings appears first in northern latitudes, and gradually darkens toward the equator, precisely the reverse of the unfolding of plant life on the Earth. From Mars our Earth would show its tropical vegetation the year round, while in Mars no tropical vegetable coloration would appear until water from the melting polar snow caps animates its growth.

Lowell shows conclusively that the seas are not seas, nor the canals waterways, nor the spots lakes. Apparently, the spots appear not so much by an increase in size as by a deepening in tint. They start, it would seem, as big as they are to be, but faint in tone; they then proceed to darken throughout. If these spots are areas of vegetation, the explanation of their appearance is at once evident. Even more markedly unnatural is another phenomenon of this phenomenal system, of which almost every one has heard and almost nobody has seen,--the double canals. Upon a part of the disk where, up to that time, a single canal has been visible, of a sudden, some night, in place of the single canal, twin canals are perceived, similar in character and inclination, absolutely parallel, reminding one of the twin rails of a railroad track. The regularity of the thing is startling. In details the doubles vary, chiefly, it would seem, in the distance the twin lines lie apart. Lowell says the widest he has seen is the Ganges, in which six degrees separate the two lines,--in the narrowest, the Phison, four degrees and a quarter. From 120 to 175 miles of clear country is found between the paralleling lines. "One element of mystery may be eliminated at the outset.... It is perceived of a sudden, by the observer, because of some specially favorable night. But it has been for some time developing. So much is apparent from my observations. Suggestions of duality occurred weeks before the thing stood definitely revealed. Furthermore, the gemination may lie concealed from the observer some time after it is quite complete, owing to lack of favorable atmospheric conditions. For it takes emphatically steady air to see it unmistakably." Each canal has its individual behavior of doubling, and the varying widths, and their evident seasonal relations utterly forbid the conception that their appearance is due to optical illusion. Mr. Lowell feels tolerably sure that the doubling, or gemination of the canals, show that the phenomenon is not only seasonal but vegetal. Why it should take this form is one of the most pregnant problems about the planet. For it is the most artificial-looking phenomenon of an artificial-looking disk.

We quote a paragraph from the concluding chapter in his book: "To review, now, the chain of reasoning by which we have been led to regard it probable that upon the surface of Mars we see the effects of local intelligence. We find, in the first place, that the broad physical conditions of the planet are not antagonistic to some form of life; secondly, that there is an apparent dearth of water upon the planet's surface, and, therefore, if beings of sufficient intelligence inhabited it, they would have to resort to irrigation to support life; thirdly, that there turns out to be a network of markings covering the disk, precisely counterparting what a system of irrigation would look like; and, lastly, that there is a set of spots placed where we should expect to find the lands thus artificially fertilized, and behaving as such constructed oases should. All this, of course, may be a set of coincidences, signifying nothing; but the probability points the other way. As to details of explanation, any we may adopt will undoubtedly be found, on closer acquaintance, to vary from the actual Martian state of things; for any Martian life must differ markedly from our own."

* * * * *

In this brief résumé of Lowell's work on Mars but scant justice has been done to the many novel and convincing suggestions in explanation of the varied features marking the surface of Mars. There are many enigmas, however, awaiting solution, if we endeavor to explain them by comparison with the methods pursued by man on this Earth, and Mr. Lowell frankly admits the many difficulties in the way of a clear solution. I have already mentioned how puzzling the checker-board appearance of our Western townships would seem to a Martian, but this comparison does not help us to understand the so-called gemination of the canals, though we might have parallel sets of canals, as we have parallel lines of railways. The enormous distance which the water travels in the Martian canals must presuppose an artificial method of urging it on. Precisely how this operation might be accomplished is a question to be solved by the mechanical and hydraulic engineer.

Beside the doubling, or so-called gemination, of the canals, there are other enigmas in the markings. At certain times there has been observed in the equatorial region of Mars a number of white spots, which have greatly puzzled the student of Mars and for which no explanation has yet been offered. That they are not clouds is seen in the fact that they do not move or drift. Furthermore these white spots are fixed features of the region, as they appear in the same places. It might be suggested that they represent snow-capped elevations or mountain peaks, but this is difficult to believe, as an examination of the terminator of Mars reveals no evidences of high elevations. These white spots appear only in mid-summer, which would argue against the idea of their being snow caps, as in mid-summer they would certainly melt and disappear. The time of their appearance coincides with the time of greatest equatorial heat. For a reasonable suggestion it might be offered that these white spots are due to vegetation of some kind. The cotton belt of the South, if one could imagine the cotton bolls a little larger and more crowded together, would make white areas. Masses of white flowers, such as the whiteweed or daisy, may be seen covering hundreds of acres of meadow land in New England. I have noticed from the tops of mountains in New Hampshire, in July, extensive meadow lands resembling fields of snow from the profusion of white daisies. The blossoming of fruit trees in the Santa Clara valley, California, whitens the surface for miles. Since the appearance of these white spots in Mars corresponds with the period of greatest evaporation, it is conceivable that an intelligence in Mars might utilize the same method which has been recently adopted in Connecticut and Porto Rico in the raising of tobacco; namely, to protect the fields with white cotton cloth; or, as in Florida, where extensive orange groves are covered with white cloth to guard against sudden frost. That this supposition has something to commend it may be seen in the accompanying reproduction of a photograph (Plate I), made in Porto Rico, of tobacco plantations when the fields are covered with white cloth supported on suitable frames. This picture appeared in an article by Eugene P. Lyle, Jr., on Porto Rico, in the January number of "World's Work," to the publishers of which we are indebted for the privilege of using it.

These various guesses may all be wrong, as, after all, we are judging Mars from conditions belonging to our own planet. This, however, we are compelled to do, as we have no other standards of comparison.

TOBACCO CULTIVATION UNDER CLOTH, PORTO RICO]

TESTIMONY OF ASTRONOMERS

That there may be types of life of some kind on Mars is, I should think, quite likely.

SIR ROBERT BALL.

In the following chapter are presented abstracts from memoirs, communications, etc., of a few among the many astronomers and observers who have recognized the markings on the planet, and, in many cases, have made drawings of them. Before presenting these few brief records, I have compiled, from Camille Flammarion's great work on Mars, the names of those astronomers whose drawings he reproduces in this monograph, for such it is. A brief examination of Flammarion's volume will give one an idea of the extent and variety of work which has already been accomplished in interpreting the surface features of Mars, and the number of astronomers who have made contributions to the subject.

Flammarion divides these observations into three periods; the first, beginning with the rude drawing of Fontana, in 1636, followed by Huyghens, in 1659, Cassini, in 1666, and many others up to Harding, in 1824. In this period the drawings were rude, though a number of the more conspicuous features were established, and above all, the existence of what was interpreted as snow in the white polar caps. Astronomically many points were determined, such as an approximation of the period of revolution, the distance of Mars from the Sun, the diameter of the planet, its mass, the inclination of its axis, the eccentricity of its orbit, its period of rotation, etc.

The second period begins with the remarkable work of Beer and Mäedler, in 1830 and subsequent years. To them belongs the honor of being the first astronomers to make a chart of the planet. An advance standard was set for future studies, and the work which followed revealed details in the surface markings never before suspected. The second period, from 1830 to 1877, includes the observations and drawings of Beer and Mäedler, 1830; Sir John Herschel, 1830; Galle, 1837; Warren de la Rue, 1856; Webb, 1856; Secchi, 1858; Liais, 1860; Schmidt, 1862; Lockyer, 1862; Phillips, 1862; Lassell, 1862; Knott, 1862; Kaiser, 1862; Dawes, 1864; Franzenne, 1864; Williams, 1867; Proctor, 1867; Lahardeley, 1871; Burton, 1871; Wilson, 1871; Gledhill, 1871; Flammarion, 1873; Terby, 1873; Green, 1873; Trouvelot, 1873; Lohse, 1873; Holden, 1875.

The third period extends from 1877 to 1892, when Flammarion published his book. The following drawings are given: Flammarion, 1877-88; Paul and Prosper Henry, 1877; Neisten, 1877-79-81-88; Terby, 1877-79-88; Van Ertborn, 1877; Cruls, 1877; Dreyer, 1877-79; Lohse, 1877-79-83-84; Green, 1877; Schiaparelli, 1877-79; Maunder, 1879; Konkoly, 1879; Boeddicker, 1881-84; Burton, 1882; Trouvelot, 1884; Knoble, 1884; Denning, 1886; Perrotin and Thollon, 1886; Proctor, 1888; Perrotin, 1888; Holden and Keeler, 1888; Wislicenus, 1888-90; W. H. Pickering, 1890; Williams, 1890; Giovannozzi, 1890; Guillaume, 1890.

It is impossible to follow these various drawings of Mars from the earliest ones of the first period, many of little value, to the slow yet certain advance as seen in the more detailed drawings of the second period, without realizing the gradual improvement of the telescope, coupled with a greater number of observers endowed with better eyesight and impelled by deeper interest in the work. In the third period, culminating with the great work of Schiaparelli, and confirmed by the remarkable observations of Perrotin and Thollon, we see the results of still more arduous devotion to the work; a great advance in telescopes, with better definition, and, in the case of the observations at Nice and Milan, a steadier atmosphere through which to observe. Flammarion brought his work up to 1892.

Lowell's work on Mars, though of a kind with Schiaparelli, is, in every circumstance accompanying it, so remarkable that we may well consider the standard now set by him as the beginning of another period; and this period will fix a standard which will consist in securing observers who, in the language of Sir David Gill, have a special faculty, an inborn capacity, a delight in the exercise of exceptional acuteness of eyesight and natural dexterity, coupled with the gift of imagination as to the true meaning of what they observe. With this standard established, there must also go a perfect telescope for definition, mounted on an elevation a mile and a half or more above the level of the sea, in a region of the clearest and steadiest atmosphere in the world.

One cannot help reflecting on these various drawings presented in Flammarion's work, and wondering what the results would have been if all these astronomers could have had telescopes as incomparable as that at Flagstaff, perched on some high mountain peak with a clear and steady atmosphere continuous for weeks, and, superadded to all these advantages, independent fortunes to enable them to transport their telescopes thousands of miles south when a favorable opposition of Mars occurred at a low altitude.

The astronomers who have advanced certain theories to explain the markings may be counted as admitting their existence, whatever they may be. Among the other astronomers to be referred to are, first, those who admit the markings, and have in all likelihood seen them; second, those who have observed and made drawings of the markings; and, third, those who have drawn them and admit, or at least do not deny, their artificiality.

Miss Agnes M. Clerke, an astronomical writer of great merit, who has written a most lucid and comprehensive "History of Astronomy in the Nineteenth Century," says: "The canals of Mars are an existent and permanent phenomenon." Mr. Thomas Lindsay, of Toronto, read some notes before the Astronomical Society of that city in regard to the phenomenon of the so-called doubling of the canals and the explanation advanced that it was due to errors in focusing. "It had been stated by several English observers that, by racking the eyepiece within or without the focus, all the phenomena might be produced." In the case of Mars, however, he asks: "How is it possible that all the observers had their telescopes unadjusted, and, if any one had, would he not be immediately aware of it?" Mr. Lindsay thought that the theory was too obviously opposed to the simplest kind of common sense to merit a moment's consideration.

Mr. John A. Patterson, in his Presidential address before the Astronomical Society of Toronto, in speaking of Mars, said the discoveries rest on the bed rock of scientific evidence; and, after speaking of the supposed spectroscopic evidence that there was no atmosphere in Mars, refers to the polar snow caps, their melting, and the lines of vegetation that are supposed to mark the margin of the canals, and he asks: "Is it possible that all these may be consistent with no vapor floating above the surface? Is it sound philosophy to conclude that the condition of things on our own little world gauges the possibilities and relations that exist in our sister world? Dame Nature does not turn out all her products in one pattern."

Mr. Denning, in the "Astronomische Nachrichten," No. 3926, gives the result of his observations on Mars in 1903. He says the canals, without doubt, are objective features; changes in the appearance of these markings he attributes to vaporous condensations. One rotation period of the planet satisfies the observation of all the markings, thus proving them to be definite features of the planet's surface rather than drifting vapors such as are seen when observing Jupiter and Saturn. In spite of these admissions Mr. Denning, in 1905, while repeating his convictions as to the objectivity of the canals, denied their sharp outline. Of the ten canals he drew, eight were discovered by Schiaparelli, and two were discovered by Lowell. Denning observed these lines with a ten inch reflector. Schiaparelli compared them in sharpness to lines of a steel engraving. It rests with the reader to judge who is most likely to be correct in his description of the character of the lines--Mr. Denning with a ten inch reflector, in a poor atmosphere, or Schiaparelli and Lowell, with a twenty-six and a twenty-four inch refractor, respectively, in a far superior atmosphere.

Among the many who have seen and drawn the canals comes first, of course, Professor Schiaparelli, the discoverer of them. It is only necessary to state here that he first detected these enigmatical markings, which he named canali, in 1877. In the opposition of 1879, he not only confirmed the discoveries of 1877, but added new canali, and for the first time saw the curious process of doubling, or gemination.

Astronomers in various parts of the world searched in vain for these markings, and despite the exalted character and remarkable work of the distinguished Italian in other lines of astronomic research, it was feared that, in this instance, Schiaparelli had been the victim of an hallucination. It is true that from the time of Huyghens, in 1659, a few astronomers, such as Secchi, Schroeter, Kaiser, and Dawes, have detected and drawn a few faint lines which seemed to be identical with the canali of Schiaparelli. It was not until 1886, however, that Perrotin and Thollon with a twenty-nine inch refractor of the Nice Observatory, first began to confirm the discoveries of Schiaparelli, and since that time observers in various parts of the world have detected and drawn these remarkable lines. The cumulative testimony of these men as to the veritable existence of these markings cannot be set aside.