to be bodies of water, or seas, and have been described and named
as such by astronomers. Lowell shows, however, that there is every
reason to doubt this conclusion. "To begin with, they are of every
grade of tint,--a very curious feature for seas to exhibit, unless
they were everywhere but a few feet deep; which, again, is a most
singular characteristic for seas that cover hundreds of thousands of
square miles in extent,--seas, that is, as large as the Bay of Bengal.
The Martian surface would have to be amazingly flat for this to be
possible. We know it to be relatively flat, but to be as flat as all
this would seem to pass the bounds of credible simplicity. Here, also,
Professor W. H. Pickering's polariscope investigations come in with
effect, for he found the light from the supposed seas to show no trace
of polarization. Hence, these were probably not water."
Lowell also shows that if these regions were seas, or water surfaces
of the shallowest kind, sunlight would certainly be reflected from
some portion of the surface so as to be visible from the Earth. A
calculation of the region from which such a beam of light might be
reflected has been carefully made, but no light of this nature has ever
been seen. These regions change in color, and Schiaparelli suggested
that in some way these changes were dependent on the Martian seasons.
Lowell, by continuous observations covering many presentations of the
planet, has demonstrated that the changes in color are synchronous
with the seasons, and they further show that these regions change in
expanse as well. The reader must refer to Lowell's book to understand
the very minute way in which the author traces out the behavior of
these so-called seas as the Martian summer advances and autumn comes
on. His evidence is overwhelming that the regions heretofore regarded
as seas are vast tracts of vegetation, doubtless on lower levels, or
depressions of the surface, old sea bottoms, in fact, where springs
and the natural settlings of stray waters might keep the ground
sufficiently moist to support a scanty growth. The regions not marked
by the dark shading, from their reddish and yellowish tinge, have
always been regarded as land, probably desert land, as they remain
fixed from year to year, dead and unchangeable as deserts are.
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.[3] 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.[4]
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.
[Illustration: 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.