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.
PLATE I
TOBACCO CULTIVATION UNDER CLOTH, PORTO RICO
V
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.
It seems strange that nine years should elapse before an astronomer with an interest in the subject, coupled with an acute vision and the patience to observe assiduously, should arise to confirm the existence of these markings, but in another chapter I have called attention to the little interest astronomers have manifested in planetary markings of any kind. It has been shown elsewhere that acute vision, with a clear and, above all, a steady atmosphere, are the chief essentials in making out the markings. It is curious to note the attitude of some astronomers, who, having seen the canals and even drawn them, denied their veritability. Their explanations cover "illusions due to the property of light itself, the inability of the eye to maintain its mechanism of accommodation, the behavior of air waves, temporary alteration of the focus of the eye, undetected astigmatism," etc., etc. But, to return to the astronomers who have drawn them. On the unfavorable opposition of 1888, Schiaparelli declares that "the canali had all the distinctness of an engraving on steel, with the magical beauty of a colored engraving." He furthermore says: "As far as we have been able to observe them hitherto, they are certainly fixed configurations upon the planet, the Nilosyrtis has been seen in that place for nearly one hundred years and some of the others for at least thirty years."
In this connection it is interesting to quote from Schiaparelli who, until many years after he discovered the canals of Mars, had no doubt of their natural origin. As late as 1893, he still considered them natural. In speaking of the canals, he says: "It is not necessary to suppose here the work of intelligent beings; and in spite of the almost geometric appearance of their whole system, for the present we incline to believe that they are product of the evolution of a planet, much as on the Earth is the English Channel, or the Channel of Mozambique." This extract may be found in a memoir in "Natura ed Arte," 1893, page 22. On page 24 of the same memoir Schiaparelli illustrates the elasticity of his mind and a thoroughly unprejudiced attitude by saying: "Their singular aspect, and the fact that they are drawn with absolute geometric precision, as if they were the product of rule and compass, have induced some people to see in them the work of intelligent beings, inhabitants of the planet. I should be very careful not to combat this supposition, which involves no impossibility." (The italics are ours.) His comparison of the Martian lines with the English Channel and the Channel of Mozambique, if he means any resemblance in form and not in the manner of formation, is most unfortunate, for on the whole face of the Earth he could not have mentioned surface features more totally unlike any feature of the Martian surface, as drawn by him, than these two channels: the English Channel, 100 miles wide at its mouth and 200 miles long, tapering to the Straits of Dover; the Mozambique Channel, hour-glass shaped, 1,100 miles long, and, at its narrowest part, 260 miles wide, and at either end nearly 700 miles wide. Had he suggested the Red Sea, 1,200 miles long, or the Straits of Malacca, 350 miles long, a nearer resemblance to the canals of Mars might have been seen, though even here it would be impossible to find their counterparts in Mars. These channels are merging with the ocean, are nearly half the width of their length, and enlarge at both ends, while the canali of Mars run for hundreds of miles as straight as ruled lines. How slight the resemblance is may be appreciated by comparing the following figure of the Earth (Fig. 1), upon which the Red Sea, the English and the Mozambique Channels and the Straits of Malacca are indicated.
In 1897 Schiaparelli becomes still more convinced of their artificiality. In his Memoir XXV, in the Reale Academia del Lincei, in speaking of the canals, he says: "This whole arrangement presents an indescribable simplicity and symmetry which cannot possibly be the work of chance." In a letter to Mr. Lowell, dated December 4, 1904, he writes: "Your theory of vegetation becomes more and more probable." Mr. A. Stanley Williams, in the "Observatory" for June, 1899, in a paper entitled "Notes on Mars," described the appearance of certain canals, regions, etc., in great detail. He notices that at the crossing of the canals a little dark spot occurs, a feature, he says, which was first elucidated by Professor Lowell in 1894. Mr. Williams also noticed the black streak bordering the northern snow cap, which Mr. Lowell in his book on Mars has interpreted as a body of water resulting from the melting snow.
In the Quarterly Journal of the Astronomical Society of Wales, the Rev. Theo. E. R. Phillips publishes an excellent drawing of Mars in color. In this drawing he shows a large number of regions, a number of canals, and other features which, he says, "came out with the clearness and sharpness of an engraving, and bore no resemblance to the 'diffused streaks' or amorphous smudges one sees for the canals in imperfect seeing." In this drawing the polar snow caps show with remarkable vividness.
Professor W. H. Pickering, in a continuous record of observations on Mars, published in the "Annals of the Lowell Observatory," records under August 20: "The dark north canals are also noticeable, and, had they looked as they now do, could not possibly have been missed on the 16th."
Dr. Phil. Fauth has, with a seven inch objective, drawn and published sixty-three drawings of Mars in which a great many canals are shown, a list of which he presents in his memoir on the subject.
The lamented Perrotin, for some time Director of the Nice Observatory, in company with M. Janssen, at Meudon, observed Mars through the great equatorial (32-2/3 inch), and published the results in the "Comptes Rendues" (Vol. CXXIV, No. 7). He describes the several zones, the northern equatorial zone "being more particularly the zone of the extraordinary canals, the discovery of which we owe to Schiaparelli, and to which we ourselves, by our publication, in 1886, called the attention of the astronomical world."
The London "Nature," March 17, 1904, in noting the death of M. Henry Perrotin, speaks of him as one of the ablest advocates of astronomical science. He devoted much time to Mars. "Aware that he was working at the extreme limit of visibility, and knowing the tendency for self-deception to creep in and impair the value of such delicate observations, he sought opportunities of making similar measures and records with different instruments, and under varied conditions, in order to remove, so far as possible, the evils of bias and partiality from the results of his researches."
Dr. Terby of Louvain, in a memoir entitled "Physical Observations of Mars," a translation of which appeared in the "Astronomical and Astrophysical Journal," No. 106, identifies many of Schiaparelli's canali and other details depicted in Schiaparelli's map of Mars. In conclusion Dr. Terby says: "After what we have seen we dare affirm that henceforth the progress of areography will be in the hands of those alone who, freeing themselves from the shackles of doubt, will resolutely engage in the way traced by the celebrated astronomer of Milan. A new era has begun in the study of Mars by the discovery of canals and their doubling, and by the micrometric determination of one hundred and fourteen fundamental points on the map, an era succeeding to that which was inaugurated a half century ago by the construction of the first two hemispheres and by the approximate fixing of fourteen points by Mäedler." Dr. Terby further says: "But these results have an incontestable value in the presence of the incredulity with which certain astronomers still consider the beautiful discoveries of Milan. Who would believe it? In spite of the beautiful drawings of M. Perrotin one reads still that the discoveries of M. Schiaparelli have not been confirmed by the largest instruments."
In "Astronomy and Astrophysics," No. 108, is published a series of contributions on Mars by Professors Edward C. Holden, William H. Pickering, C. A. Young, Lewis Swift, George C. Comstock, E. E. Barnard, and H. C. Wilson. All of these men are astronomers and all are connected as directors or observers with various observatories in the United States. Many sent sketches, most of them saw the canals, all saw the polar snow caps and darker regions. To say that these astronomers were sketching details which existed only in their imagination is simply preposterous.
Professor Herbert A. Howe, Director of the Chamberlin Observatory, at Denver, in his "Elements of Descriptive Astronomy" says: "If we have simply to answer the question, 'Would a man, as constituted at present, if transported to Mars find it possible to exist there?' The most probable answer is, 'No.' While one must not be dogmatic, it may be said, with some assurance, that the man would gasp a few times and die. However, it is conceivable that manlike beings might find a home there." Mr. Howe could have said without being dogmatic that a man thus transported would die of what is known as Caisson disease.
Among those who assert that the canals are artificial we have Professor Percival Lowell as pre-eminent. He has erected an observatory in the region of one of the clearest atmospheres in the world, has furnished it with the finest telescope that Clark ever made, and for the chief purpose of studying the surface features of Mars. In his interesting book on Mars he has presented the results of his observations in so lucid and convincing a manner that a reviewer of the English edition of the work, in an English astronomical journal, is led to write: "We may say at once that we feel bound to accept these observations as sufficient evidence of the real existence of the markings without expressing an opinion as to what they may be." The reviewer ends by saying: "Indeed, there is a subtle deftness in the way Mr. Lowell deals with his observations which gives the impression that he has been there and seen it all, and it is really hard to say why we cannot accept his conclusions. It is probable, because we are shy to receive new facts at a first statement. In time, no doubt, we shall be willing to accept his deductions (or facts) as to the markings. We were about to advance objections, but they seem poor, and really it is a case where each person must read and form his own ideas—but by all means read."
We have already presented a summary of his observations. We may add here, however, an extract from his book on the solar system. In this Mr. Lowell says of Mars: "What we see hints of the existence of beings who are in advance of, not behind us in the journey of life," and again: "Life on Mars must take on a very different guise from what it wears on the Earth. It is certain there can be no man there—that is as certain as anything can be. But this does not preclude a local intelligence equal to, and perhaps easily superior to, our own. We seem to have evidence that something of the sort does exist there at the present moment and has made imprint of its existence far exceeding anything we have left on Mother Earth."
George W. Morehouse, in his "Wilderness of Worlds," says: "Taken all together we must regard Mars as probably an inhabited world and very similar to the Earth."
Mr. Hector Macpherson, Jr., member of the Astronomical Society of France, in his interesting book "Astronomers of To-day," says, in regard to Mr. Lowell's book on Mars: "He does not ask us to believe anything fantastical or extravagant. His hypothesis has been framed to account for all the various Martian features. At present we can only say that it is the most comprehensive and probable theory yet advanced to explain the phenomena of the red planet."
Professor Todd, Director of the Astronomical Observatory at Amherst College, in his book on Stars and Telescopes, in referring to drawings of a region in the southern portion of Mars, known as the Solis Lacus, and a complicated drawing of another region, says: "Whether one views this marvellous and intricate system as a whole, or in some portion of high detail, it is difficult to escape the conviction that the canali have, at least in part, been designed and executed with a definite end in view."
There are many who do not deny the existence of some forms of life on the planet, but are not prepared to admit the existence of intelligent creatures. Sir Robert Ball expresses himself as follows: "That there may be types of life of some kind on Mars is, I should think, quite likely."
The number of astronomers above quoted, who have seen and drawn the canals, might be augmented, but a sufficient number have been cited to show that the evidence of the presence of these markings does not rest with a few, furthermore, some of these observers can only interpret the markings as the result of intelligent action. It may be urged that among those quoted are some whose opinion may not have great weight since they are not professional astronomers. One must insist that the study of planetary markings as well as the interpretation of their meanings comes not only within the province of planetary astronomers, but that any broad-minded man, with an acute eye and familiar with the sciences connected with the surface features of the Earth, is quite competent to make observations of his own and to judge of the merits of the question.
VI
THE STUDY OF PLANETARY MARKINGS
Their singular aspect, and the fact that they are drawn with absolute geometric precision as if they were the product of rule and compass, have induced some people to see in them the work of intelligent beings, inhabitants of the planet. I should be careful not to combat this supposition which involves no impossibility.
Schiaparelli.
It is a question whether, after all, the study of planetary markings comes within the province of astronomers. Not more, perhaps, than the study of physical geography and subjects connected with the surface features of the Earth, comes under the cognizance of those whose profession it is to determine the oscillation of the pole, the Earth's movements due to the Moon, etc. Indeed, these lines of research are strictly astronomical. With the study of the surface markings of the Moon, or Mars, features of an entirely different kind are to be interpreted, and quite a different equipment is necessary. It is no wonder, then, that astronomers, the most conservative of all classes of investigators, should view with suspicion the results of the work of Schiaparelli, Lowell and others. Immersed in mathematics, trusting in nothing that cannot be measured and reckoned, as a class holding their imagination in abeyance, is it any surprise that they should present an attitude of indifference and even hostility to the work of those who, differently equipped mentally, have attempted a definition and solution of the riddle of the Martian markings? To appreciate how foreign to the studies of an astronomer is the interpretation of the canals of Mars, one has simply to scan the index of any astronomical publication, or the titles of papers in the transactions of astronomical societies. For example, take volumes XX and XXI of the "Astronomical Journal" and tabulate the papers, memoirs, etc., therein published, numbering two hundred and thirty-eight, and we find of these, seventy-four on the stars; sixty-two on the comets; nineteen on planets and satellites, mostly mathematical; eighteen on the Sun; eighteen on the asteroids; fifteen on Eros; ten on polar motion and latitude; four on Nova Persei; and seventeen miscellaneous, consisting of logarithms, instruments, Gegenschein, etc.; and only one on Mars, and this on the polar snow caps!
As to the question whether it is more important to add another to the thousands of variable stars and binaries, and hundreds of asteroids, already determined, or to consider whether we are alone in the universe and, if so, the significance of it, I think with the intelligent public there can be no doubt.
A fair sample of the subjects which occupy the astronomers' mind, and which are so remote from the study of planetary markings, and have so little interest for the public, may be gathered from the following list selected at random from an astronomical publication. Notes on variable stars; Maxima and minima of long period variables; Micrometrical measurements of the companion of Procyon; The problem of three bodies; Ephemeris of Comet a, 1901; On the eruptive energy of the stars; Eclipse cycles; Determinations of the aberration-constant from right ascension; Theory of a resisting medium upon bodies moving in parabolic orbits; Weights and systematic corrections of meridian observation in right ascension and declination; and other titles equally profound. Many of these memoirs consist of hundreds of pages of figures, and, as a friend of mine observed, not a column footed up! Take for example a title like the following: "Method of developing the perturbative functions, also precepts for executing their development." This memoir is accompanied by pages of algebraic formulæ which the layman turns over in despair, the only illumination consisting of a few words in English which render the gloom still more apparent,—such words as "hence," "or," "we therefore have," "if we put." Of what we "have," and why we "put," we are left in profound ignorance. Now I venture to believe that the great world of humanity takes but little interest in such pages, or in the kinds of titles above given, though fully realizing that they mean something and represent important steps in astronomic research. It would add greatly to the value of these contributions if a brief summary in plain English could be given at the end of these papers, but it is the rarest event that these collectors of data ever make any generalizations, or form any deductions.
My faith in the appalling character of algebraic formulæ5 received a rude shock when I learned of an experience of Louise Michel, the anarchist, who was transported for life to New Caledonia (afterwards pardoned). On arriving at the savage island, true to her humanitarian instincts, "she immediately established a school for native children, who by a curious freak of their minds, she noted with rejoicing, took naturally to algebra before they learned arithmetic!"
Hovenden quotes Huxley as saying that mathematics "is that study that knows nothing of observation, nothing of induction, nothing of experiment, nothing of causation." He also quotes the words of Clerk Maxwell, who said, in regard to mathematicians, that it was "doubtful whether the ideas as expressed in symbols had ever quite found their way out of the equations into their minds." They never seem to appeal to the doctrine of probabilities nor do they in any way permit imagination to act as a stimulus to suggestive thought.
Least of all would a layman ridicule or question the painstaking labor involved in astronomic work, though he cannot see a glimmer of light or intelligence in the enigmatical pages. A certain class of astronomers might take a lesson from an intelligent public in ceasing to scoff and ridicule what they are unable to see themselves in the Martian markings. The chief work of these men indicates the cold precise measuring of points of light in the heavens, the determination of orbits, elements and ephemeris of heavenly bodies, the determination of solar parallax, etc., most of the subjects strictly mathematical, a question of careful measurements for which the necessary instruments are at hand, or simply sweeping the heavens for a new variable, binary or asteroid. Parallaxes and orbits are matters of measurement to be reckoned by the figures of anybody else. It is obvious from all this that little or no interest is manifested by astronomers in planetary markings, least of all in those of Mars. The exasperating feature of the matter is that they persistently repudiate the observation of others equally well equipped, and endowed with the same enthusiasm and devotion to their work.
The way in which the gatherers of the raw material arrogate to themselves the science of astronomy, relegating the thinkers and generalizers to the limbo of speculation, is as if the book-keepers of a corporation should assume themselves to be the master-minds of the concern and the banker, or financier, at the head of it, a dreamer not worth regarding.
An illustration of the conservativeness of astronomers in regard to planetary markings is shown in their cautious attitude concerning the polar snow caps of Mars. Here are white polar caps on Mars, precisely where they ought to be if they are snow, they wax and wane at the time they should and at no other time, a dark band appears at their borders as the caps in turn diminish in size, which has been interpreted as water due to the melting snow, and no other substance known could possibly reproduce these varying conditions. Professor C. A. Young, in describing these white areas, says: "The one which happens to be turned toward the Sun continually diminishes in size, while the other increases, the process being reversed with the seasons of the planet." After these admissions Professor Young cautiously says: "These are believed to be ice caps." Sir John Herschel says: "The variety in the spots may arise from the planet not being destitute of atmosphere and clouds, and what adds greatly to the probability of this is the appearance of brilliant white spots at the poles—one of which appears in our figure—which have been conjectured with some probability to be snow, as they disappear when they have been long exposed to the Sun, and are greatest when just emerging from the long night of the polar winter." Had Michael Faraday been an astronomer, how long would it have taken him to pronounce these white polar caps snow and ice? De la Rive, in his memoir of Faraday, in speaking of his marvellous accomplishments, says: "One may easily understand what must be produced under such circumstances by a life thus wholly consecrated to science, when to a strong and vigorous intellect is joined a most brilliant imagination." Tyndall, in his discourse "On the Scientific use of the Imagination," says: "Bounded and conditioned by co-operant reason, imagination becomes the mightiest instrument of the physical discoverer. Newton's passage from a falling apple to a falling Moon was a leap of the imagination."
That Herbert Hall Turner, Professor of Astronomy in the University of Oxford, does not regard the various contributions on the surface features of Mars as belonging to astronomical science may be inferred from his interesting book lately published, entitled "Astronomical Discovery." This book presents to us the history of the discovery of Uranus and Eros, of Neptune, Bradley's aberration of light, Schwabe and sun-spot period, the variation of latitude, etc., but not a word about the marvellous discoveries of the canali of Mars by Schiaparelli, so fully confirmed by the observation and drawings of many others, and the great advances made by Lowell in the discovery of new features with his lucid and rational interpretation of the seeming enigmas.
Astronomy, the oldest and most conservative of all the sciences, has been the last to subdivide. Already one group of men has justified by its work a division of the science known as astrophysics. The lamented Keeler, in explaining the difference between astronomy and astrophysics, said: "Astrophysics seeks to ascertain the nature of the heavenly bodies, rather than their positions and motions in space, what they are, rather than where they are." This natural division suggests the propriety of making another division equally distinct, which should comprise the study and interpretation of the surface markings of the planets and satellites, under the name of planetology. The study would be the application to these bodies of the science of geology, in its broadest sense, meteorology, physical geography, geodesy, and related sciences.
With the science of planetology established, the student of this science will no longer call to his aid the astronomer, and, least of all, the astrophysicist, nor will he be mindful of their criticism or neglect. He will appeal to the sciences which are involved in the study of the surface features of his own globe, in the interpretation of planetary detail.
VII
DIFFICULTIES OF SEEING
It is contrary to all the analogies of nature to suppose that life began only on a single world.
Simon Newcomb.
For years I had been familiar with different representations of Mars in which the surface features had been strongly depicted in black and white; in other words, photo-reliefs, or engravings incorporated with the printed page. I had unwittingly come to believe that these features were equally distinct when one observed Mars through the telescope. I had not then seen Schiaparelli's original memoir in which his wonderful map presents the canals in light and tenuous lines, which are, however, as clear cut as the lines of a steel engraving, to use his words. For a long time I had hoped for a chance to observe Mars through a large telescope in a clear and steady atmosphere. It seemed reasonable to me—knowing nothing about it—that one who had traced out under the microscope delicate lines and structural features in diaphanous membranes, who had, in fact, used a microscope with high powers for forty years, would find it child's play to make out the canals, oases, regions, etc., of Mars, as represented in the various publications on the subject. Professor Percival Lowell, of Flagstaff, Arizona, finally gave me the opportunity I so much desired, and, through his courtesy and kindness, I was enabled to observe Mars every night for nearly six weeks through his twenty-four inch refractor, the last and probably the best telescope ever made by Clark, mounted in one of the steadiest atmospheres in the world and at an altitude above sea-level of over 7,000 feet. Imagine my surprise and chagrin when I first saw the beautiful disk of Mars through this superb telescope. Not a line! not a marking! The object I saw could only be compared in appearance to the open mouth of a crucible filled with molten gold. Slight discolorations here and there and evanescent areas outlined for the tenth of a second, but not a determinate line or spot to be seen. Had I stopped that night, or even a week later, I might have joined the ranks of certain observers and said "illusion" or something worse. And right here it was that my experience in microscopic work helped me, for, remembering the hours—nay, days—I had worked, in making out structural features in delicate organisms which my unprofessional friends could not see at all, I realized that patient observation would be required if I was to be successful in my efforts. My despair, however, was overwhelming when Professor Lowell and his assistants, looking for a few moments at the same object, would draw on paper the features which had been plainly revealed to them, consisting of definite shaded regions, a number of canals and other markings, of which, with the utmost scrutiny, I could hardly detect a trace. For the first time I realized that observing fixed diaphanous membranes under a microscope with rigid stand, and within four inches of one's nose, was quite a different matter from observing a brilliant disk 4,200 miles in diameter, 52,000,000 miles away, with an oscillating atmosphere of unknown depth between. Night after night I examined this golden, opalescent disk, drawing each time such features as I could convey by memory from the ocular to the drawing table, and, little by little, new features were detected, and to my delight the drawings agreed with those made by the others. Since the drawings made by the four observers coincided, it was evident that we had not been victims of subjective phenomena. Furthermore, as I discovered afterwards, by comparison, the drawings I made not only agreed with theirs but with those made by other observers, at different times, in other parts of the world. So slow were my acquisitions, however, that it soon became evident that at least months of continuous observation would be necessary before the more delicate markings would be revealed to me. It is interesting to learn that others have had a similar experience. Mr. A. Stanley Williams, of England, in an article entitled "Notes on Mars" ("Observatory," June, 1899), in stating the difficulties of observation, says: "My eye invariably requires at least two months of continuous observation of a planet before it acquires its full sensitiveness to the most minute details."
In this connection it is well to state that Mr. Lowell began the observation of Mars when he was a mere boy. His first telescope, which he still has, was a two and a quarter inch refractor. His observations were made from the roof of his house in Boston, and with this small glass he defined the general shaded regions that Huyghens had detected and drawn in 1659. Since then Mr. Lowell has observed in turn through a six inch, an eighteen inch of Brashear, and, for the last few years, through a twenty-four inch refractor made by Clark especially for this work.
To refute the accumulated observations of Mr. Lowell one must have the same acute eye, and a record of the same continuous and devoted study. Nothing short of that experience will avail. The jealous derision that has gone up from some observers endowed with less acuteness of vision is neither dignified nor just. Were these Martian details based upon the observations of Lowell alone, one might be inclined to say that some vagary of the mind had led him to imagine these markings which were first detected by the great Italian astronomer Schiaparelli. Up to the present time—to mention only a few—observations and drawings have been made by Perrotin, Thollon, and Flammarion, of France; Dr. Phil. Fauth, of Germany; Williams, of England; Lowell, W. H. Pickering, Douglass, Lampland, and Schaeberle, of America, while many others have made drawings of the more conspicuous details. With this record it is impossible to deny the existence of these markings essentially as they are drawn.
The difficulty of seeing the more delicate markings of the planet is unquestionable, and an examination of astronomical literature, from which we shall make numerous quotations, indicates only too plainly the acuteness of vision, and the time and care necessary to make competent observations. Sir Robert Ball says, in one of his recent works: "The detection of the Martian features indicates one of the utmost refinements of astronomical observations." Macpherson, in his "Astronomers of To-day," thus writes of Schiaparelli, "Professor Schiaparelli's observations have been distinguished by his keen-sightedness and care. He has taken every precaution to avoid all disturbances resulting from personal equation, and has found it well to adopt the rule (which he here quotes) 'to abstain from everything which could affect the nervous system, from narcotics and alcohol, and especially from the abuse of coffee, which I found to be exceedingly prejudicial to the accuracy of observation.'" What I might have accomplished in the way of seeing had I followed the wise example of Schiaparelli I do not know. A not too strict abstemiousness in any of these matters, coupled with long daily walks on the Mesa, with its fascinating flora and fauna, found me in the observer's chair every night, somewhat fatigued mentally and physically.
Sir Robert Ball, in his "Popular Guide to the Heavens," in describing the difficulty in making out the more delicate markings of Mars, says: "It should be understood that in the unsteady air of England it is almost hopeless to expect many of the finer details; not even in the most favorable climates are they to be seen always, or all at once, and much training of the eye is required before it is fit to decide for or against the existence of these details on the verge of invisibility." As another illustration, perhaps, of the difficulties of seeing, Sir Robert, in the same book, says: "Observers of Mars are divided into two camps, those who see the canals, and those who do not. The former are in the strong position that they are perfectly sure that they see what they represent in their drawings."
From the foregoing it must be evident that not only are the finer markings on Mars most difficult to see even under the best conditions but that exceptional acuteness of vision, which few possess, united with long practice, is necessary to make out the tenuous lines which enclose the field of Mars like a net. That Mr. Lowell has had a long and continuous practice, covering years, in observing Mars through the steadiest of atmospheres and with a superb glass, is simply a statement of fact. It may be said without fear of contradiction that he has devoted more time to the observation of Mars than all the other observers combined. Has he then an exceptional acuteness of sight, coupled with indefatigable industry, in the pursuit of this quest to which he is devoting his life and fortune? The following instance will illustrate his marvellous eyesight. We were walking along the shores of a lake some miles from Flagstaff, the expanse of shore left by the rapidly evaporating waters abounding with thousands of very small black spiders running hither and thither at our approach. I told him of one I had just seen in which the abdomen was covered with minute young spiders which the mother was carrying about with her—a well-known habit of certain species. This curious fact I had detected only while stooping close to the ground in search of minute shells. Mr. Lowell, while walking along, immediately began scanning the ground for the trace of a spider with minutely granulated abdomen, and finally exclaimed: "There is one of them!" On stooping down to examine the object it proved to my astonishment to be a female carrying its young in the way already described. This incident revealed a remarkable acuteness of vision to detect, while standing erect and walking, this tiny spider among hundreds of others of its species that were scampering away at our approach.
Not only is acuteness of vision necessary to one who is to study planetary markings, but of importance also is a clear, and above all a steady atmosphere; and, strange as it may appear, telescopes of moderate size seem to be the instruments with which the best work has been done. It is also true in astronomy, as in warfare, that it is not the biggest gun but the man behind the gun that does the most efficient work. As an evidence of the importance of steady atmosphere Professor W. H. Pickering, in his observations on the satellites of Jupiter, says his work had two important bearings: "First, as showing the relative importance of atmosphere versus aperture for delicate visual observations of this sort. In the same category would be included studies of planetary detail as distinguished from the examination of very faint objects. In other words, if an observer wishes to study very faint stars he must have a large telescope. If he wishes to study the neighboring planets and brighter satellites he may use a small telescope, but he must have a very good atmosphere."
The importance of a clear and steady atmosphere, for delicate observation, is known to all astronomers. The rarity of such days, even in our clear atmosphere so superior to that of England, is not generally known. Forty years ago Dr. Henry Draper, in an address entitled "Are Other Worlds Inhabited?" in speaking of Mars and the difficulties of seeing, said: "One of the greatest obstacles to distinct vision is our own atmosphere. Its currents and motions tend to confuse the outlines of objects, and, according to my experience, a whole year may pass without the occurrence of more than one good night. The only remedy is to carry the telescope as high up on a mountain as possible, so as to leave below the more injurious portions of the atmosphere. It might be possible to work 15,000 feet above the sea in the neighborhood of the Equator." I quote these words that the general reader may appreciate the advantages Lowell has with his fine telescope south of all European observatories, in the latitude, say of Algiers, at a high altitude, and in the dry and steady atmosphere of Arizona, with uninterrupted seeing for weeks together, and each night far superior to any night which Greenwich could ever be blessed with.
Professor W. H. Pickering attests to the importance of a steady atmosphere in studying the Moon from a station in Jamaica, when he says that, with a five inch refractor, he was able to detect minute details which were not revealed by the far larger telescopes at Harvard University.
Mr. W. D. Barbour, President of the Leeds Astronomical Society, using his four inch achromatic, says: "In one of those brief intervals of atmospheric steadiness I saw distinctly a number of well-known markings," the names of which he gives. Dr. Phil. Fauth, using a seven inch refractor, made sixty-three drawings of Mars, showing in wonderful detail the canals, oases, etc. Mr. W. J. Lockyer, in London "Nature," testifies that "a keen and patient observer, sitting at the eyepiece of a comparatively small equatorially mounted telescope, if he makes his observations carefully, and with due regard to atmospheric conditions for good seeing, can do more useful and valuable work than one who has a large aperture at his command and employs it indifferently." Mr. E. Ledger, in speaking of Dawes, who made a remarkable map of Mars, says he was justly famed for the remarkable distinctness of his vision; he had detected and drawn a few lines which seemed to be identical to those of Schiaparelli.
In the authorities above quoted we have endeavored to show that a steady atmosphere, a persistent devotion to the work, accompanied by acute vision, and also a talent for observation, are all the factors needed, not only to confirm the remarkable discoveries of Schiaparelli and Lowell, but possibly to detect, at favorable moments, new features which have escaped the eyes of these keen observers.
At this point we cannot resist giving the words of Sir David Gill, Director of the Royal Observatory at the Cape of Good Hope. Professor S. W. Burnham, of the Lick Observatory, in reviewing a memoir entitled "Double Star Observations at the Cape of Good Hope," quotes as follows from the preface: "Sir David Gill, in speaking of the routine character of the work involved in the investigation, says: 'There is no instance, as far as I know, of a long and valuable series of double star discovery and observation made by a mere assistant acting under orders. It is 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 he observes, that imparts to the observer the requisite enthusiasm for double star observing. No amount of training or direction could have created the Struves, a Dawes, or a Dembowski. The great double star observer is born, not made, and I believe that no extensive series of double star measurement will ever emanate from a regular observatory, through successive directorates, unless men are specially selected who have previously distinguished themselves in that field of work, and who were originally driven to it from sheer compulsion of inborn taste.'" If the reader will substitute the words planetary markings for double star in the above quotation from Sir David Gill's report, he will understand why we have ventured to italicise certain lines, and will appreciate their significance. In no stronger or truer words could one have emphasized the conditions involved in a critical study of the surface features of Mars.
In the experience of an astronomer, it is not an unusual occurrence that an object in the heavens, fairly conspicuous, remains unseen until by some lucky chance an observer sweeping the sky picks it up, and, having determined its position, it is promptly found by others. Professor H. H. Turner, in his "Astronomical Discovery of the Nineteenth Century," says: "It is a common experience in astronomy that an observer may fail to notice in a general scrutiny, some phenomenon which he can see perfectly well when his attention is called to it; when a man has made a discovery, and others are told what to look for, they often see it so easily that they are filled with amazement and chagrin that they never saw it before."
In the Rev. T. W. Webb's interesting book on "Celestial Objects for Common Telescopes," a reminiscence of the author is given by a friend in which the following is related as illustrating the varying ability of observers in seeing. "A curious instance of difference of vision was well illustrated one superb evening when Mr. Webb and the writer were observing Saturn with the nine and a half inch refractor at Hardwick. Mr. Webb saw distinctly the division in the outer ring which the writer could not see a trace of, while the writer picked up a faint point of light which afterwards turned out to be Enceladus (a satellite) which Mr. Webb could not see."
In my brief observation of Mars I probably might have made out many more details if I had permitted Mr. Lowell to tell me what to see, and where to look for them on the disk. This I would not allow him to do, nor did I study any of the numerous drawings in his own work, or the original memoirs of Schiaparelli, or other works containing drawings of Mars in his library. I would not learn the names of any of the regions, or canals, nor with a single exception do I know them now. Only when I had finished my last night's observations, did Mr. Lowell take my drawings and write out a list of the various canals, oases, etc., which I had made out. Thus, unaided, I drew simply what was plainly evident, though many other details flashed out for a second, which were not recorded, simply because I did not see them often enough to be sure of their precise position on the disk.
Mr. Lowell points out one of the reasons why so many observers and astronomers have not seen the canals. In the third volume of the "Annals of the Lowell Observatory" he refers to a certain series of observations of Mars, made in 1894, and says: "Not only was there no sign of a canal, but even the main markings showed disheartingly indefinite." "This vacancy of expression was due to the Martian date." "It was the very nick of time to see nothing, for the part of the planet most presented to the Earth was then at the height of the dead season, and in this fact lies the key to much past undetection and present unbelief in the phenomenon of the canals."
VIII
VARIATION IN DRAWING
Let us not cheat ourselves with words. Conservatism sounds finely and covers any amount of ignorance and fear.
Percival Lowell.
Much doubt has been expressed as to the existence of the so-called canals in Mars and other surface markings of that planet in consequence of the discrepancy seen in the drawings of the more delicate features by various observers. While in the main a certain general resemblance is seen in the topographical character of the network of lines, and a more close resemblance in the darker markings, notably the Syrtis Major, the disagreement in the minor details has led certain astronomers to deny their existence altogether, or to insist that most of the markings were subjective, or due to poor focusing, or the result of aberration of the eye or lens. Professor Simon Newcomb, in his "New Astronomy for Everybody," in speaking of the work of the observers at the Lick Observatory and the great telescope at their command coupled with favorable situation, says: "It is therefore noteworthy that the markings on the face of Mars as presented by Barnard do not quite correspond to the channels of Schiaparelli and Lowell." Newcomb also reproduces in his book the drawings of a region in Mars known as Solis Lacus, made by Campbell and Hussey, and finds they do not show an exact agreement between them. Now such objections might have some weight if drawings made by different observers of the Solar Corona, for example, or the Nebula of Orion, or the Milky Way had any close resemblance. As a matter of fact, these various drawings depart far more widely from the originals, as shown by photographic reproduction, than do the various drawings of Mars. Mr. Fison, in his "Recent Advances in Astronomy," in speaking of the divergence in the drawings made by different observers, says: "In inspecting sketches of the delicate details of the Corona of the Sun made at the same place by different observers, it is difficult to believe that the same object has been represented." To appreciate how widely divergent such drawings are one has only to refer to the United States Naval Observatory publication on the Total Eclipse of the Sun, July 29, 1878.