SUMMARY
If, now, we review with the mind’s eye the several features of Mars
which we have surveyed with the bodily one, we shall be surprised to
find to what they commit us. Suggestive as each is considered by
itself, the _ensemble_ into which they combine proves of multiplicate
force in its implication. For each turns out to fit into place in one
consistent whole, a scheme of things in which are present all the
conditions necessary to the existence and continuance of those
processes which constitute what we call life. In short, we are
conducted with a cogency, which grows as we consider it, to the
conclusion that Mars is habitable.
Two ways of appreciating this cogency are open to us. We may treat it
with the simple reasoning of common-sense, as we should a dissected map
or a piece of machinery in which we realize we are right when the
several parts at last fit together and the picture stands revealed or
the machine works. Or we may subject the evidence to quantitative
estimates for and against by the doctrine of probabilities, and thus
evaluate the chances of its being correct. Consciously or
unconsciously, this is what we are about in our decisions every day of
our lives. At the one end of the line are those skillful judgments
where the balance is so keen-edged that the least overweight on the one
side dips the scales to a conclusion. At the other extremity stand
those deductions which we usually speak of as proved, such as the law
of gravitation. But both assurances rest really upon probability and
differ only in degree. What we mean by proof of anything is that a
supposition advanced to account for it explains all the facts and is
not opposed to any of them, and that the balance of probability in
consequence is very largely in its favor.
Now, if several pieces of evidence, distinct in their origin, concur to
a given conclusion, the probability that that conclusion is correct is
far greater than what results from each alone; and mounts up soon to
something much exceeding what bettors at races call certainty odds.
However unversed the average man may be in calculating the probability,
he recognizes the fact in his dealings with his fellows by the way he
attaches weight to concurrent testimony. It is such concurrent evidence
that we have now to consider. To this end we will marshal the several
facts ascertained in a summarized list for their easier intercomparison.
These facts are:—
(1) Mars turns on its axis in 24 h. 37 m. 22.65 s. with reference to
the stars, and in 24 h. 39 m. 35.0 s. (as a mean) with regard to the
Sun. Its day, therefore, is only about forty minutes longer than ours.
(2) Its axis is tilted to the plane of its orbit by about 23° 59′ (most
recent determination, 1905). This gives the planet seasons almost the
counterpart of our own in character; but in length nearly double ours,
for
(3) Its year consists of 687 of our days, 669 of its own.
(4) Polar caps are plainly visible which melt in the Martian summer to
form again in the Martian winter, thus implying the presence of a
substance deposited by cold.
(5) As the polar caps melt, they are bordered by a blue belt, which
retreats with them. This excludes the possibility of their being formed
of carbon dioxide, and shows that of all the substances we know the
material composing them must be water.
(6) In the case of the southern cap, the blue belt has widenings in it
in places. These occur where the blue-green areas bordering upon the
polar cap are largest.
(7) The extensive shrinkage of the polar snows shows their quantity to
be inconsiderable, and points to scanty deposition due to dearth of
water.
(8) The melting takes place locally after the same general order and
method, Martian year after year, both in the south cap,
(9) And in the north one. This is evidenced by the recurrence of rifts
in the same places annually in each. The water thus let loose can,
therefore, be locally counted on.
(10) That the south polar cap is given to greater extremes than the
north one, implies again, in view of the eccentricity of the orbit and
the tilt of the axis, that deposition in both caps is light.
(11) The polar seas at the edges of the caps being temporary affairs,
the water from them must be fresh.
(12) The melting of the caps on the one hand and their reforming on the
other affirm the presence of water vapor in the Martian atmosphere, of
whatever else that air consist.
(13) Since water vapor is present, of which the molecular weight is 18,
it follows from the kinetic theory of gases that nitrogen, oxygen, and
carbonic acid, of molecular weights 28, 32, and 38 respectively, are
probably there, too, owing to being heavier.
(14) The limb-light bears testimony to this atmosphere.
(15) The planet’s low albedo points to a density for the atmosphere
very much less than our own.
(16) The apparent evidence of a twilight goes to confirm this.
(17) Permanent markings show upon the disk, proving that the surface
itself is visible.
(18) Outside of the polar cap the disk is divided into red-ochre and
blue-green regions. The red-ochre stretches have the same appearance as
our deserts seen from afar,
(19) And behave as such, being but little affected by change.
(20) The blue-green areas were once thought to be seas. But they cannot
be such, because they change in tint according to the Martian season,
and the area and amount of the lightening is not offset at the time by
corresponding darkening elsewhere;
(21) Nor by any augmentation of the other polar cap or precipitation
into cloud. It cannot, therefore, be due to shift of substance.
(22) Furthermore, they are all seamed by lines and spots darker than
themselves which are permanent in place; so that there can be no bodies
of water on the planet.
(23) On the other hand, their color, blue-green, is that of vegetation;
this regularly fades out, as vegetation would, to ochre for the most
part, but in places changes to a chocolate-brown.
(24) The change that comes over them is seasonal in period, as that of
vegetation would be.
(25) Each hemisphere undergoes this metamorphosis in turn.
(26) That it is recurrent is again proof positive of an atmosphere.
(27) The changes are metabolic, since those in one direction are later
reversed to a restoration of the original status. Anabolic as well as
katabolic processes thus go on there; that is, growth as well as decay
takes place. This proves them of vegetal origin.
(28) The existence of vegetation shows that carbonic acid, oxygen, and
undoubtedly nitrogen, are present in the Martian atmosphere, since
plants give out oxygen and take in carbonic acid.
(29) The changes in the dark areas follow upon the melting of the polar
caps, not occurring until after that melting is under way;
(30) And not immediately then, but only after the lapse of a certain
time.
(31) Though not seas now, from their look the dark areas suggest old
sea bottoms, and when on the terminator appear as depressions (whether
because really at a lower level or because of less illumination is not
certain).
(32) That they are now the parts of the planet to support vegetation
hints the same past office, as water would naturally drain into them.
That such a metamorphosis should occur with planetary aging is in
keeping with the kinetic theory of gases.
(33) Terminator observations prove conclusively that there are no
mountains on Mars, but that the surface is surprisingly flat.
(34) But they do reveal clouds which are usually rare and are often, if
not always, dust-storms.
(35) White spots are occasionally visible, lasting unchanged for weeks,
in the tropic and temperate regions, showing that the climate is
apparently cold,
(36) But at the same time proving that most of the surface has a
temperature above the freezing-point.
(37) In winter the temperate zones are more or less covered by a
whitish veil, which may be hoar-frost or may be cloud.
(38) A spring haze surrounds the north polar cap during the weeks that
follow its most extensive melting.
(39) Otherwise the Martian sky is perfectly clear; like that of a dry
and desert land.
The way in which these thirty-nine articles fit into one another to a
mortised whole is striking enough at first sight, but becomes more and
more impressive the more one considers it. For some are due to one kind
of observation, some to another. In the taking they are unrelated; yet
in the result they agree. Equally pregnant is the history of their
acquisition. Most of them were detected as the outcome of observations
at the opposition of 1894, and led to the theory which was published in
the writer’s first book on the subject. Others are the result of the
five oppositions that have since occurred. These have proved entirely
corroborative of the previous ones and of the theory then deduced, and
that in two distinct ways: first, by the accumulated evidence they have
brought to the matter along the old lines; and, secondly, by what they
have revealed in new directions. Of these thirty-nine articles of
Martian scientific faith in observation or deduction, (9), (10), (21),
(22), (25), (27), (28), (30), (33), (35), (36), and (38) are in whole
or part new. That continued scrutiny is thus corroborative of the
earlier results, both along the old and along new lines of
investigation, warrants additional confidence in the conclusion.
Considering, now, these counts, we see that they make reasonably
evident on Mars the presence of:—
1. Days and seasons substantially like our own;
2. An atmosphere containing water vapor, carbonic acid, and oxygen;
3. Water in great scarcity;
4. A temperature colder than ours, but above the Fahrenheit
freezing-point, except in winter and in the extreme polar regions;
5. Vegetation.
First and foremost of these is air. In order to make it possible for
vital processes of any sort to take place, the body of a planet must be
clothed with an atmosphere, by the modesty of nature, the old
astronomers would have said. Such a covering subserves two purposes: it
keeps out the cold of space, thus permitting the maintenance of a
temperature sufficient to support life, and it affords a medium through
which metabolism can go on.
Now the presence of air is attested first and foremost by the fact of
change in the Martian markings, (12), (13), (26), (28), and (35). The
changes observed are conspicuous; are both inorganic (in the case of
the polar caps), (12), (13), and (35), and metabolic or organic, (26)
and (28), (in the case of the blue-green areas); that is, they consist
of building up as well as of pulling down and are planet-wide in
occurrence. Such changes could not occur in the absence of an
atmosphere. They show that this atmosphere consists of water vapor,
(5), carbonic acid, and oxygen, (28).
The limb-light, the apparent evidence of a twilight arc and the
planet’s low albedo indicate that this atmosphere is thin. The
appearance of the surface, (35), suggests cold, indicative again of a
thin air. Such tenuity is in accord with what _a priori_ principles
would lead us to expect, and tends to show that reliance on general
principles is here not misplaced, a point of some interest.
Lastly, the occurrence of clouds, (34), visibly floating and traveling
over the surface, and haze at times, (38), proves in another way the
existence of the medium in which alone this could be possible.
Water is the next substance vital to planetary life. As to its actual
presence the polar caps, (4)-(12), have most to say; as to its relative
absence, the rest of the disk, (17)-(22). The forthright conception of
the polar caps as composed of snow and ice is borne out by further
investigation into what could cause the observed phenomenon. Carbonic
acid, the only other substance we know capable in any way of resembling
what we see, turns out not capable of producing one important detail of
the caps’ appearance, the blue band, (5), which accompanies them in
their retreat. Water alone could do this.
The melting of the caps shows that water vapor must be a constituent of
the Martian atmosphere. Moreover, as the molecular weight of water
vapor is less than that of oxygen or nitrogen or carbon dioxide, if the
former can exist in the atmosphere of the planet, _a fortiori_ must
these other gases. So that from this we have knowledge of the
possibility of the presence of oxygen, nitrogen, and carbon dioxide
there. From (28) we saw that their actual existence is demonstrated.
The next step is the ascertainment that the water is in very small
amount. The extensive melting of the caps, (7), shows their quantity to
be inconsiderable, which is the first fact pointing to a dearth of
water. The second comes from the aspect and behavior of the
reddish-ochre regions which proclaim them deserts, (18) and (19); the
third from the detection of the character of the blue-green areas as
not seas, (20), (21), and (22). In several different ways, study of
these regions asserts their non-aquatic constitution, the easiest to
appreciate being that they are traversed by permanent dark lines and
other equally sedentary markings, (22). No bodies of water, therefore,
are to be seen outside of the ephemeral polar seas, immediately
surrounding the caps as they melt.
This leads us to the third presence on Mars indicative of a living
world: vegetation. The other two spoke of substances necessary to life,
the premises in the case, this one of organic existence itself, its
conclusion. The evidence consists of static testimony from the look of
the blue-green areas, (23), and of kinematic derived from their
behavior, (24), (25), (26), and (27). Vegetation would present exactly
the appearance shown by them, and nothing that we know of but
vegetation could. But suggestive as their appearance is, it is as
nothing compared with the cogent telltale character of their behavior.
The seasonal change that sweeps over them is metabolic, constructive as
well as destructive, that is, and proclaims an organic constitution for
them such as only vegetation could produce. In tint their metamorphoses
are those of the same substance. For the blue-green lapses into ochre
and revives again to blue-green just as vegetation does on our own
Earth at the proper season of the year, taking both the Sun and the
advent of water into the reckoning. Furthermore, certain of the largest
dark areas turn to a chocolate-brown at times, which is the color of
fallow ground and suggestive, at least, as occurring where the
blue-green at other seasons is the most pronounced. Lastly, the change
occurs at the epoch at which, from a knowledge of the melting of the
polar caps, theory demonstrates that it ought to take place if it be
due to the action of vegetation.
That this was the case was evident from much less information than is
forthcoming today; but what is significant, each new fact discovered
about the planet goes to show that it is unquestionably true.
PART II
NON-NATURAL FEATURES
CHAPTER XV
THE CANALS
From the detection of the main markings that diversify the surface of
Mars we now pass to a discovery of so unprecedented a character that
the scientific world was at first loath to accept it. Only persistent
corroboration has finally broken down distrust; and, even so, doubt of
the genuineness of the phenomena still lingers in the minds of many who
have not themselves seen the sight because of the inherent difficulty
of the observations. For it is not one where confirmation may be
summoned in the laboratory at will, but one demanding that the watcher
should wait upon the sky, with more than ordinary acumen. This
latter-day revelation is the discovery of the canals.
Quite unlike in look to the main features of the planet’s face is this
second set of markings which traverse its disk, and which the genius of
Schiaparelli disclosed. Unnatural they may well be deemed; for they are
not in the least what one would expect to see. They differ from the
first class, not in degree, but in kind; and the kind is of a wholly
unparalleled sort. While the former bear a family resemblance to those
of the earth; the latter are peculiar to Mars, finding no counterpart
upon the earth at all.
Introduction to the mystery came about in this wise, and will be
repeated for him who is successful in his search. When a fairly acute
eyed observer sets himself to scan the telescopic disk of the planet in
steady air, he will, after noting the dazzling contour of the white
polar cap and the sharp outlines of the blue-green seas, of a sudden be
made aware of a vision as of a thread stretched somewhere from the
blue-green across the orange areas of the disk. Gone as quickly as it
came, he will instinctively doubt his own eyesight, and credit to
illusion what can so unaccountably disappear. Gaze as hard as he will,
no power of his can recall it, when, with the same startling
abruptness, the thing stands before his eyes again. Convinced, after
three or four such showings, that the vision is real, he will still be
left wondering what and where it was. For so short and sudden are its
apparitions that the locating of it is dubiously hard. It is gone each
time before he has got its bearings.
By persistent watch, however, for the best instants of definition,
backed by the knowledge of what he is to see, he will find its coming
more frequent, more certain and more detailed. At last some
particularly propitious moment will disclose its relation to well-known
points and its position be assured. First one such thread and then
another will make its presence evident; and then he will note that each
always appears in place. Repetition _in situ_ will convince him that
these strange visitants are as real as the main markings, and are as
permanent as they.
Such is the experience every observer of them has had; and success
depends upon the acuteness of the observer’s eye and upon the
persistence with which he watches for the best moments in the steadiest
air. Certain as persistence is to be rewarded at last, the difficulty
inherent in the observations is ordinarily great. Not everybody can see
these delicate features at first sight, even when pointed out to them;
and to perceive their more minute details takes a trained as well as an
acute eye, observing under the best conditions. When so viewed,
however, the disk of the planet takes on a most singular appearance. It
looks as if it had been cobwebbed all over. Suggestive of a spider’s
web seen against the grass of a spring morning, a mesh of fine
reticulated lines overspreads it, which with attention proves to
compass the globe from one pole to the other. The chief difference
between it and a spider’s work is one of size, supplemented by greater
complexity, but both are joys of geometric beauty. For the lines are of
individually uniform width, of exceeding tenuity, and of great length.
These are the Martian canals.
Two stages in the recognition of the reality confront the persevering
plodder: first, the perception of the canals at all; and, second, the
realization of their very definite character. It is wholly due to lack
of suitable conditions that the true form of the Martian lines is
usually missed. Given the proper prerequisites of location or of eye,
and their pencil-mark peculiarity stands forth unmistakably confessed.
It is only where the seeing or the sight is at fault that the canals
either fail to show or appear as diffuse streaks, the latter being a
halfway revelation between the reality and their not being revealed at
all. Much misconception exists on this point. It has been supposed that
improved atmospheric conditions simply amount to bringing the object
nearer by permitting greater magnification without altering the hazy
look of its detail.[2] Not so. They do much more than this. They steady
the object much as if a page of print from being violently shaken
should suddenly be held still. The observer would at once read what
before had escaped him for being a blur. So is it with the canals. In
reality, pencilings of extreme tenuity, the agitations of our own air
spread them into diffuse streaks; an effect of which any one may assure
himself by sufficiently rapid motion of a drawing in which they are
depicted sharp and distinct, when he will see them take on the streaky
look. As the writer has observed them under both aspects, and has seen
them pass from the indefinite to the defined as the seeing improved, he
has had practical proof of the fact, and this not once, but an untold
number of times.
Atmospheric conditions far superior to what are good enough for most
astronomic observations are needed for such planetary decipherment, and
the observer experienced in the subject eventually learns how
all-important this is. Under these conditions the testimony of his own
eyesight upon the character of these markings is definite and complete.
And the first trait that then emerges from confusion is that the
markings are _lines_; not simply lines in the sense that any
sufficiently narrow and continuous marking may so be called, but lines
in the far more precise sense in which geometry uses the term. They are
furthermore straight lines. As Schiaparelli said of them: they look to
have been laid down by rule and compass. The very marvel of the sight
has been its own stumbling-block to recognition, joined to the
difficulty of its detection. For not only is the average observatory
not equipped by nature for the task, but what is not good air often
masquerades as such. Trains of air waves exist at times so fine as to
confuse this detail, or even to obliterate it entirely; while at the
same time they leave the disk seemingly sharp-cut, with the result that
one not well versed in such vagaries thinks to see well when in truth
he is debarred from seeing at all. When study of the conditions finally
ends in putting him upon the right road, the sight that rewards him can
hardly be too graphically described.
Next to the fact that they are _lines_, definiteness of direction is
the chief of their characteristics to strike the observer. The lines
run straight throughout their course. This is absolutely true of ninety
per cent of them, and practically so of the remaining ten per cent,
since the latter curve in an equally symmetric manner. Such directness
has I know not what of immediate impressiveness. Quite unlike the
aspect of the main markings, which show a natural irregularity of
outline, these lines offer at the first glance a most unnatural
regularity of look. Nothing on Earth of natural origin on such a scale
bears them analogue. Nor does any other planet show the like. They are,
in fact, distinctively Martian phenomena. This is the first point in
which they differ from the markings we have hitherto described. The
others were generic planetary features; these are specific ones,
peculiar to Mars.[3]
Equally striking is the uniform width of each line from its beginning
to its end, as it stands out there upon the disk. The line varies not
in size throughout its course any more than it deviates in direction.
It counterfeits a telegraph wire stretched from point to point. Like
the latter seen afar, the width, too, is telegraphic. For it is not so
much width as want of it that is evident. Breadth is inferable solely
from the fact that the line is seen at all, and relative size by
difference of insistency. Indeed, the apparent breadth has been
steadily contracting as the instrumental, atmospheric, and personal
conditions have improved. All three of the factors have conduced to
such emaceration, but the middle one the most. For the air waves spread
every marking, and the effect is relatively greatest upon those which
are most slender. As the currents of condensation and rarefaction pulse
along, their denser and their thinner portions refract the rays on
either side of their true place, and thus at the same time confuse a
marking and broaden it. The consequence is that the better the
atmospheric conditions and the more that has been learned about
utilizing them, the finer the lines have shown themselves to be.
Herein we have a specific intrinsic difference between the fundamental
features and these lines: the main markings have extension in two
dimensions, the latter in one.
Distinctive as they thus are, they have, in keeping with their
appearance, been given a distinctive name, that of canal. Useful as the
name is and, as we shall later see, applicable, it must not be supposed
that what we see are such in any simple sense. No observer of them has
ever considered them canals dug like the Suez Canal or the phœnix-like
Panama one. This supposition is exclusively of critic creation.
Their precise width is not precisable. They show no measurable breadth
and their size, therefore, admits for certain only of an outside limit.
They cannot be wider than a determinable maximum, but they may be much
less than this. The sole method of estimating their width is by
comparison of effect with a wire of known caliber at a known distance.
For this purpose a telegraph wire was stretched against the sky at
Flagstaff, and the observers, going back upon the mesa, observed and
recorded its appearance as their stations grew remote. It proved
surprising at what great distances a slender wire could be made out
when thus projected against the sky. The wire in the experiment was but
0.0726 of an inch in diameter and yet could be seen with certainty at a
distance of 1800 feet, at which point its diameter subtended only 0.69
of a second of arc. How small this quantity is may be appreciated from
its taking more than ninety such lines laid side by side to make a
width divisible by the eye. Such slenderness at the then distance of
Mars would correspond, under the magnification commonly used, only to
three quarters of a mile. Theoretically, then, a line three quarters of
a mile wide there should be visible to us. Practically, both light and
definition is lost in the telescope, and it would be nearer the mark to
consider in such case two miles as the limit of the perceptible. With
the planet nearer than this, as is often the case, the width which
could be seen would be proportionally lessened. Perhaps we shall not be
far astray if we put one mile as the limiting width which could be
perceived on Mars at present, with distance at its least and definition
at its best.
That so minute a quantity should be visible at all is due to the line
having a sensible length and by summation of sensations causing to rise
into consciousness what would otherwise be lost. A stimulus too feeble
to produce an effect upon a single retinal rod becomes recognizable
when many in a row are similarly excited.
The experiment furnished another criterion, of importance as regards
the supposition that the lines on Mars are illusory. It showed that
brain-begotten impressions of wires that did not exist could be told
from the real thing when the wire subtended 0.69 of a second of arc or
more; that below this the outside stimulus was too weak to differ
recognizably from optic effects otherwise produced; while when the real
wire was diminished to 0.59′′, it could not be seen at all. Now, the
majority of lines on Mars so far recognized and mapped lie in strength
of impression far above the superior limit of 0.69′′. To one versed in
Martian canal detection there is no possibility of self-deception in
the case, the canals being very much more salient objects to an expert
than those who have not seen them suppose. For it must not be imagined
that, when one knows what to be on the lookout for, they are the
difficult objects they seem to the tyro. Just as the satellites of Mars
were easily seen once they were discovered, so with these lines.
A mile or two we may take, then, with safety as the smallest width for
one of the lines. The greatest was got by comparing what is by far the
largest canal, the Nilosyrtis, with the micrometer thread. From such
determination it appeared that this canal was from 25 to 30 miles wide.
But it is questionable whether the Nilosyrtis can properly be termed a
canal, so much does it exceed the rest. It is certainly far larger than
the majority of them. From comparative estimates between its size and
that of the others, 15 to 20 miles for the width of the larger of the
Martian canals seems the most probable value, and 2 or 3 miles only of
the more diminutive of those so far detected.
[Illustration: Showing the Eumenides-Orcus.]
On the other hand, the length of the canals is relatively enormous.
With them 2000 miles is common; while many exceed 2500, and the
Eumenides-Orcus is 3540 miles from the point where it leaves the Phœnix
Lake to the point where it enters the Trivium Charontis. This means
much more on Mars than it would on Earth, owing to the smaller size of
the planet. Such a length exceeds a third of the whole circumference of
its globe at the equator. But what is still more remarkable, throughout
the whole of the long course taken by the canal, it swerves neither to
the right nor to the left of the great circle joining the two points.
Of these several peculiarities of the individual canal it is difficult
to know to which to allot the palm for oddity,—great circle
directness, excessive length, want of width, or striking uniformity.
Each is so anomalously unnatural as to have received the approving
stamp of incredulity. Yet so much, wonderful as it is, is encountered
on the very threshold of the subject.
-----
Footnote 2:
M. l’abbé Moreux.
Footnote 3:
As some misrepresentation has been made on this subject through
misapprehension of the writer’s observations on Venus and Mercury, it
may be well to state that the tenuous markings on both these other
planets entirely lack the unnatural regularity distinguishing the
canals of Mars. The Venusian lines are hazy, ill-defined, and
non-uniform; the Mercurian broken and irregular, suggesting cracks.
Neither resemble the Martian in marvelous precision, and have never
been called canals by the writer nor by Schiaparelli, but solely by
those who have not seen them and have misapprehended their character
and look.
CHAPTER XVI
THEIR SYSTEM
Much more stands beyond. For, outdoing in suggestiveness the individual
traits of the lines, is the relation shown by them to one another. It
is the communal characteristics of the phenomenon that are most
surprising.
The individual peculiarities of the lines impress themselves at once;
the communal, only as the result of experience, collation, and thought.
As the observer becomes trained, the more lines he is able to make out,
until they fairly seam the whole surface of the light areas of the
planet. Their name collectively is legion; while to name them
individually is fast getting, for the number detected, to be
impossible. As with the increasing family of asteroids, figures alone
will prove adequate to the task.
Interdependence, not independence, marks the attitude of the canals.
Each not only proceeds with absolute directness from one point to
another, but at its terminals it meets canals which have come there
with like forthrightness from other far places upon the planet. Nor is
it two only that thus come together at a common junction. Three, four,
five,—up to as many as fourteen,—thus make rendezvous, and it is a
poor junction that cannot show at least six or seven. The result is a
network which triangulates the surface of the planet like a geodetic
survey into polygons of all shapes and sizes, the Arian areolas. The
size of the pieces forming this tesselate ground depends solely upon
the fineness of the definition. With every increase in the power of
seeing, each areola is cut into still smaller portions, usually by
connection between its corners. Thus a polygon or rhombus is split into
triangles which may themselves be divided in like manner, the mosaic
breaking into bits, the sides of which, however, always remain
clean-cut.
From this arrangement it is at once evident that the canals are not
fortuitously placed. That lines should thus meet exactly and in numbers
at particular points, and only there, shows that their locating is not
the outcome of chance. If very thin rods be thrown haphazard over a
surface, the probability that more than two will cross at the same
point is vanishingly small. Increasingly assured is it that this would
not happen generally. The result we see is therefore not a matter of
chance, but of some law working to that end.
To the detection of what that law is precedes the easier ascertainment
of what it is not. The lines, for example, cannot be rivers, which was
the first explanation offered of them by Proctor many years ago,
because of their peculiar straightness. Nor can they be channels, the
name given to them by Schiaparelli, except in the non-committal sense
in which he used the term. For here again their geometric regularity is
bar to any estuary-like hypothesis. For quite another reason they
cannot be cracks, because of their uniform size throughout. Their
unbroken character is another fatal objection to the same suggestion.
For cracks in ground never pursue for any great distance a continuous
course, any more than they keep uniform or straight. The state of an
old ceiling is a case in point. When it breaks, it does so in fissures
that proceed a certain way, then give out to be continued by others
roughly parallel to the first, but parted from them. The same character
is shown by the rills on the moon. The ‘Straight Wall,’ so called, is
composed of three such sections, and the little rill to the right of
it, west of Birt, of four.
Thus were they seen at Flagstaff, and as, to the writer’s knowledge,
they have not been so depicted elsewhere, the fact may serve to give
some idea of the definition there.
That the underlying cause is not explosion or contraction is also
evidenced by the canals collectively as well as individually, their
arrangement into a system, for cracks, however produced, could only
originate from certain centres and could not fit into those starting
from others, as the canals invariably do. For each canal goes as
undeviatingly to one terminal as it left forthrightly from another. If
one wishes to see what explosion or contraction can do, he has only to
look at the moon through an opera-glass, when he will be shown a very
different sight from what the drawings of Mars detail. Thus just as,
considered individually, the lines cannot be watercourses because of
their straightness, so they cannot be cracks because of dovetailing
into one another.
The fact that they form a system shows that whatever caused them
operated over the whole planet, linked in cause as in effect throughout
each section. This at once negatives any purely physical cause of which
we have cognizance. For upon a globe still so subject to physical
vicissitude as Mars by its aspect shows itself to be, latitude must
tell in the phenomena its zones exhibit. Polar snows that wax and wane
speak of arctic conditions very diverse from temperate and tropic
states, and what would affect the one could not influence the other.
Yet the mesh rises superior to zonal solicitation as to local barrier.
It is not something dependent either on the temperament or the
complexion of the globe’s different parts. It transcends surface
restriction and becomes planet-wide in its working. The importance of
this omnipresence dilates in meaning as one dwells in thought upon it.
Ubiquitous as it is, the mesh which thus covers the Martian surface
like a veil spread completely over it, is unlike a veil in being of
irregular texture. Not only are the interstices of various shape and
pattern, but the mesh itself is of locally differing size. Though the
threads are straight and uniform throughout, they are not all alike,
besides being unsymmetrically interwoven. Some are at least of ten
times the coarseness of others, and from this fact and the bo-peep
effect of our air waves all are not visible at once. In consequence the
network is not so impressive at first glance as it becomes upon a
synthesis of the observations. When this is done, the surface proves to
be fairly evenly cut up, as recourse to the maps printed in this volume
will amply demonstrate. These maps, as on page 31, are made from the
results of but one opposition, and as at each opposition some zone is
in a more canal-showing state than others, owing to the Martian season
at the time, a still greater uniformity in canal distribution results
from a blending of many.
From the completeness of the mesh, it follows that in the course taken
severally by the canals no one direction preponderates over another.
Considered by and large, the canals seem to be equally distributed
round the compass points; and this at all longitudes and nearly all
latitudes. Tropic, temperate, and even arctic canals show a pleasing
impartiality in the matter of the course pursued. The only exceptions
occur in the neighborhood of the pole. There a slight tendency may be
seen to a north and south setting.
Though so much is visible in a general way from the map, it is of
interest to go into the subject with more particularity and to that end
to show it statistically. The several canals traversing each zone were
therefore counted, and the area of the zone computed. The manner of
canal distribution thus found is given in the following table, in the
second column of which stand the areas of the several zones upon the
planet, each ten degrees wide, except the one next the snow, and in the
third the number of canals found traversing them, reduced to
percentages of the 0°-10° zone. A fourth column shows the total length
of the canals in each zone, those from 0° to 20° being taken from the
1896 globe, those from 20° to 90° from the 1903. This is in order to
annul the effect of the seasons upon the showing of the canals as much
as possible.
===============+===============+===============+===============
ZONE | AREA | NO. OF CANALS | ACTUAL LENGTH
| | WTD. |
---------------+---------------+---------------+---------------
0°-10° | 1.00 | 1.00 | 1.00
10°-20° | .97 | .89 | .91
20°-30° | .91 | .93 | .72
30°-40° | .82 | .90 | .71
40°-50° | .71 | .78 | .66
50°-60° | .58 | .64 | .59
60°-70° | .42 | .43 | .42
70°-80° | .26 | .30 | .34
80°-85° | .07 | .12 | .11
===============+===============+===============+===============
The numbers continue fairly non-committal until we begin to approach
the pole, when they commence to increase. Much the same result is got
if we take the actual canal-lengths in each zone, as the fourth column
shows. The crowding of the canals poleward is marked. The canals,
therefore, are phenomena that stand in peculiar relationship to the
polar cap. This corroborates the inference about them due to their
running out of the edge of the snow. They not only emanate from it, but
they do so in numbers surpassing what is elsewhere observable over the
disk.
Otherwise is it with their departure-points. These are not scattered
haphazard over the surface, but bear to its general features definite
relations. If we consider the map, obliterating the lines, and then
seek to connect the most salient points of the planet’s topography by
direct avenues of communication, we shall find that our putative lines
fall exactly where the real ones occur. For the most part, the real
lines emanate from well-marked indentations in the dark regions, fitted
by natural position for departure-points, what, if these were seas, we
should call their most conspicuous bays. They thus leave in the
southern hemisphere the deeper folds of the great diaphragm, for the
most part; though on occasion they run out of them where they will.
From equally conspicuous points in the dark northern areas other lines
proceed; while in the centre of the continents, the canals make for
more or less salient spots, small patches of shading like the Trivium
or the Wedge of Casius, or simply round black radiants, like the Luci
Ismenii.
From this it appears that the lines are locally dependent upon the
general topography of the fundamental features of the surface. For
some reason they connect the very points most suggestive of
intercommunication. As from their characteristics it is perfectly
evident that the lines are neither rivers nor cracks, it follows that
such a communicating habit is of the most telltale character. To be
so dissimilar in kind from the main markings and yet so dependent
upon them, hints that their positioning occurred after the formation
of the main features themselves. We reach thus from the look of the
lines and their location a most striking deduction, that the lines
are not coeval with the main markings, but have come into being later
and with reference to the general topography of the planet. The
network is not only a mesh _de facto_, then, but one _de jure_,
which, subsequent to the fashioning of the seas and continents and
what these have now become, has been superposed upon them.
CHAPTER XVII
GEMINATION OF THE CANALS
Fraught with more difficulty than the detection of the lines alone is
the next discovery made upon the disk: the recognition of pairs of
lines traversing it.
In 1879, while Schiaparelli was engaged in scrutinizing the strange
_canali_ he had discovered on the planet the opposition before, he was
suddenly surprised to mark one of them double. Two closely parallel
lines confronted him where but a single one had previously stood. So
unaccountable did the sight seem, that he hesitated to credit what he
saw, being minded to attribute the vision to illusion of some sort and
the more so that it was not renewed. While he was still wondering what
it meant, the planet parted company with the Earth, carrying its enigma
with it.
When the two bodies again drew near to one another in 1882,
Schiaparelli set himself to watch for a recurrence of the strange
phenomenon. Before long it came, and more bewilderingly than at first;
for not one canal alone, but a score of them now showed in duplicate,
each presenting to his astonished gaze twin lines perfectly matched and
preserving throughout their distance apart. Suspecting diplopia or some
other optical trick, he tried various eyepieces to a test of the cause
but to no change in the effect. The twin lines continued visible, do
what he would, insisting on their own reality in spite of all
solicitation to merge. How cautious he was in the matter, and how
unwilling at first to believe the evidence of his eyes, is shown by the
care he took to guard against deception. It was not until he had
assured himself of the reality of the phenomena that he believed what
he had seen.
It so chanced that my first experience of the thing was almost equally
startling, so unexpected was it and so exceedingly sharp was the
definition at the time. It was in an autumn early twilight, through air
almost perfectly still, as the light went out of the sky and the
markings on the planet began to come forth that the Phison of a sudden
showed in duplicate to me, clear-cut upon the disk, its twin lines like
the rails of a railway track traversing Aeria. Not more vivid do those
of our transcontinental tracks appear as one sees them stretching off
into the distance upon our Western plains. More impressive was the
sight from the fact that I was not looking for it. It simply suddenly
stood forth, this strange parallelism of pencil lines. My surprise
matched the wonder of the sight.
Since then I have witnessed it several hundred times, but never with
more absolute certainty than at that first fortunate revelation. To
this distinctness is due the amazement it then aroused. Not simply
because of its surpassing novelty, but for the insistence with which it
proclaimed itself was the effect to be ascribed. Less well seen, doubt
had robbed it of its full surprise. It requires as a rule steady
definition for its initial unmistakable showing, if one would be
instantly convinced. Except for such it is not usually easy to the
unpracticed, though often discernible to the expert after it has once
been seen. But that it is real no one who had had a good view of the
sight could doubt; still less after the experience had been repeated
over and over again.
What appears to take place is this: where previously a single
pencil-like line joined two well-known points upon the disk, twin
lines, the one the replica of the other, stand forth in its stead. The
two lines of the pair are but a short distance apart, are of the same
size, of the same length, and absolutely equidistant throughout their
course. It is as if a second line had in some way been mysteriously
added to the first since the latter was last seen some weeks before.
This in a word is the phenomenon, technically called the gemination of
the canals, which has since its discovery called forth so much comment.
It is not in reality quite as simple or as sudden as it seems, but this
was the way in which the phenomenon was first seen and in which it
still continues to be criticised.
Self-assertive of reality, the double lines are patently objective to
him who is fortunate enough to see them well. Nevertheless the great
difficulty of detecting them, and the still greater difficulty of
conceiving how such things can be, has led many not versed in the
subject to disbelieve and from that to attempt to explain the sight as
illusory. Scepticism seeks self-justification; what is hard of
acceptance for its strangeness begetting hypotheses of committed error
which find easy credence for their comforting conservatism. Several
such have in consequence been propounded to account for the double
canals. There is the diplopic theory which credits them to
non-focusing; the interferential theory which would make them optical
products of the telescope; and the illusion theory which would have
them quite simply imaginary.
Inasmuch as in any research the assurance that a phenomenon is real is
the first point about it to be established, it is a scientist’s duty,
not only to scan the phenomena with jealous care to that end, but to
scrutinize every theory which would seek otherwise to account for
them—the testing such being only second in importance to observing the
things themselves. Accordingly I have examined each of the optical
theories that have been advanced and critically compared what they
assert and require with the results of observation. The outcome of this
research has proved as negativing to any other origin for the double
canals than reality as direct observations at the telescope are
positive on the point. To show this I shall review each in its
consequences, confronting it with what the telescope has to say on the
subject; for it is of the pith of the matter that the reality should be
as demonstrable on demand as on sight. Furthermore, I shall do this
before embarking on the general account of these strange things,
because it is vital to any interest that one should be assured from the
start of the truth of what he is to read. The preface may seem to him
abstruse and prosy, but it will introduce him to some curious optical
properties and will eventually enhance his concern by proving to him
that what reads like fiction is all the more wonderful for being fact.
_I. The Diplopic Theory_
Diplopia is the property of seeing double with one eye. Surprising as
it sounds it is an effect not unknown to students of optics, though it
usually requires training to produce. It is possible only when the eye
is not focused on the object, and is not always possible then. From my
experiments its feasibility seems to depend upon whether the focus be
beyond or before what it should be. If the eye be focused for a point
beyond the object, the object is doubled, if for a point this side of
it, the latter is simply blurred. When the double is formed, the amount
of the separation of the two images is a function of the distance the
focus is out. The greater the discrepancy, the wider apart is the
ensuing double. Nor does the image, of a line, for example, stop at
doubling. After a certain breadth of separation is reached a third line
appears, bisecting the interval between the other two. With yet greater
widening the third line itself splits into a pair and so the resolution
goes on. In my own experiments I have gone so far as to suspect a fifth
line. Far from being unconscious, the process of producing the
phenomenon is, with some people, of difficult accomplishment. Mr.
Lampland, for instance, of the Flagstaff Observatory, to whom we owe
the first photographing of the canals, and who sees the doubles of Mars
without difficulty, has hitherto found diplopic vision an impossible
feat. Even with the most practiced diplopia is never unconscious except
when the object viewed, as a micrometer wire, has nothing to locate it
in space. Now, the diplopic theory of the double canals supposes that
in all cases the eye of the observer is thus unconsciously out of focus.
To this method of their manufacture the telescopic phenomena prove
unamenable on five counts.
1. Focusing the eye on an object is now a reflex action, so automatic
has it become; in consequence one is commonly directly conscious when
an object is not in focus, always so when the object presents detail.
Were such not the case we should never, except by chance, see anything
defined. Observing through a telescope, after a modicum of practice,
differs in no respect from observing in everyday life. Consequently,
that an experienced observer should not know his business in so primary
a matter is preposterous. One may or may not believe that “the undevout
astronomer is mad,” but that the perpetually unfocused one would be is
beyond debate.
2. Generically unlikely, the failure to focus is here specifically out
of the question. For the observer does not use the canals to focus on
for the simple reason that he cannot. Like all delicate detail, the
doubles appear not continuously but by flashes of revelation, according
as the atmospheric waves permit of passage undisturbed. To focus on
them would be next to impossible even were it resorted to—which it
never is. By the exponents of the theory this important fact is
overlooked: the unforeseen showing of the canals and therefore the
absolute lack of complicity of the eye in the matter. What one focuses
on is the look of the main markings of the disk. Now, to suppose an
observer systematically out in his perceptions of so featureful a
planet as that of Mars, so that he does not know when he sees its image
sharp, implies a lack of knowledge of astronomic observation in the
supposer.
3. Study by the writer shows the width of a given double canal to be
constant for a given date. Within the errors of perception or recording
the twin lines are always at the same epoch the same distance apart.
The greater the number of determinations made, the nearer the result
approaches to this mean; and the greater the care used in delineation,
the less each value departs from it.
Now, if the thing were a matter of mistaken focusing, an eye could not
be thus true to its own mistakes. If it were out in its focus by a
certain amount at one time, it would be likely to be out by a different
amount at another. So that by the very terms of its making a diplopic
double would be sure to vary. Indeed, in laboratory experiments it is
impossible to prevent it. For the eye rests itself automatically by
change of focus, and if it be not consciously kept awry it reverts as
near to the true focus as it can of its own accord.
4. Diplopia might be a respecter of persons, but it certainly could not
be one of canals. For a given observer it must be objectively general
in its application to the same class of objects. Consequently, if the
doubling were diplopic, all canals inclined at the same angle to the
vertical—for the tilt might affect the result were the eye
astigmatic—should be similarly affected. Parallel canals should
parallel each other’s action. With the Martian doubles this is not the
case. Of two canals similarly inclined the one will be double, the
other not, at the same instant and under conditions that are alike. And
this persistently. For gemination is an attribute of certain canals and
never of others. At a given season of the Martian year, some canals are
regularly double, some invariably single. Night after night and
presentation after presentation these idiosyncrasies are preserved: the
doubles, always pairs, the single, always alone. Nor does the strength
of the line affect the action. The single canals are some of them
stronger, some of them weaker, than the doubles seen at the same time.
5. If of diplopic origin the mean width of all the doubles should be
the same. For though the diplopic width would vary for a given canal
according to the moment, a sufficient number of views would yield a
mean width which would be the same for all. Tilt apart, the mean width
of one canal would be that of another. Among Martian doubles, on the
contrary, I have found the width to be a specific property of the
particular canal. Each has its own mean width regardless of
inclination, and this individual width differs as between one and
another by as much as five to two, or, if we consider such canals as
the Nilokeras I and II, by more than ten to two.
Any one of these five points is fatal to the theory; _a fortiori_ all.
_II. The Interference Theory_
From the wave propagation of light it follows that the image of a
bright line made by a lens is not itself a simple bright line but a
bright band flanked by alternate dark and bright ones. It has,
therefore, been suggested that a bright medial line is here concerned
and that the double canal is the first of its dark pair of outriders.
But the suggestion does not bear scrutiny.
1. It presupposes a central streak brighter than the rest of the disk
to give birth to the twin dark lines. This should itself be visible in
the image; but no such bright backbone is seen.
2. It demands a perfectly definite width of separation for a given
aperture—which is not that observed.
3. It makes the width a function of the aperture, decreasing as this
increases—which is not sustained by observation. Different apertures
produce no effect on the widths of the Martian doubles, as the writer
has shown (Lowell Observatory Bulletin, No. 5) by a change of aperture
from twenty-four to six inches.
4. Under like optical conditions the optically produced doubles would
be all of a width; while the Martian ones show idiosyncratic widths,
each peculiar to itself.
_III. The Illusion Theory_
Known also as the Small Boy Theory from the ingenuous simplicity on
which it rests, this theory attacks the reality of the doubles by
questioning that of the canals _en bloc_. Because some boys from the
Greenwich (Reform or) Charity School, set to copy a canal-expurgated
picture of the planet, themselves supplied the lines which had
preceptorily been left out, the Martian canals have been denied
existence; which is like saying that because a man may see stars
without scanning the heavens, therefore those in the sky do not exist.
As to the instructions the boys received we are left in the dark. It
looks as if some leading questions had unconsciously been put to them.
At all events, English charity boys would seem to be particularly
pliant to such imagination, for when Flammarion retried the experiment
with French schoolboys, and even inserted spaced dots for the canals in
the copy, not a boy of them drew an illusory line.
The fact is, this is one of those deceptive half-truths which is so
much more deleterious than an unmitigated mistake. Under certain
circumstances it is quite possible to perceive illusory lines, due
either to shadings otherwise unmarked and thus synthesized or to
immediately precedent retinal impressions transferred to places where
they do not belong by rapid motion of the eye, as I had myself
discovered before the English experiment had been tried. But, as I have
also found out, these effects are produced only at the limit of vision,
and in that limbo of uncertainty the whole art of the observer consists
in learning to distinguish the true from the false. Strength of
impression, renewed effect _in situ_, and a peculiar sense of reality
or the reverse enable him to adjudge the two. More experience than the
boys possessed would have helped them to part the sheep from the goats.
But, furthermore, and fatally to the theory here in question, the
Martian canals when well seen are not at the limit of vision as its
framers supposed, but well within that boundary of doubt; so that the
premise upon which the whole theory rests gives way. Under good
atmospheric conditions the canals are comparable for conspicuousness to
many of the well-recognized Fraunhofer lines and are just as certainly
there.
Thus each attempt to prove the doubles non-objective turns out when
specifically examined to be inconsistent with the facts. With the
assurance of their reality thus made doubly sure, we pass to
consideration of the things themselves.
CHAPTER XVIII
THE DOUBLE CANALS
I
Rightly viewed, no more subtle tribute could be paid to the remarkable
character of the phenomenon of gemination than the scepticism with
which it was immediately received and which it still continues to
elicit. That the sight should be regarded as illusory speaks for its
surpassing strangeness; and so far as oddity goes the encomium is
certainly deserved. Of the bizarre features of this curiously marked
disk, the double canals were at the time of their discovery the
culmination, and though things stranger still if possible have since
been seen there, it is not wonderful that doubt should still
incredulously stare. If the mere account of them reads like romance, to
see them is an experience.
Nothing astronomical that I have ever seen has been so startlingly
impressive as my first view of a double canal. Even in narration the
thing justifies its effect. For a double canal consists of a pair of
twin dark filaments, perfectly parallel throughout their course and
inclosing between them ground of the same ochreish cast as that which
lies without. Only on occasion is this tint of their midway departed
from, and then only toward a darkening, never toward a lightening of
it. Except for appearing paired, the lines resemble precisely the usual
single canals. In length they vary from a few hundred to a few thousand
miles, while in width each component, for narrowness, hardly permits of
definite ascription.
Compared for strength with the usual canal the lines of a double seem
to hold on the average an intermediate position between the larger and
the smaller of the single canals so far detected. Owing, however, to
the massed effect of the pair by reason of their closeness, they have
an advantage in showing over the singles of two to one. And this
renders them among the most conspicuous and important meshes of the
canal network.
Like the single canals, they vary in strength with the Martian time of
year; at certain seasons developing into heavy pencil lines and at
others fading away to the merest gossamers, only just discernible like
cobwebs stretched across the face of the planet.
Although the individual constituent lines vary in aspect and never rise
at their most to cognizable breadth, the distance parting their
centres, or the width of the double, is quite measurable. The only
difficulty in the way of its determination lies in the absence of a
procurable unit small enough to mete it. The usual spider-threads of
the micrometer are colossal in comparison with these filaments and
present a standard only analogic at best. Nevertheless, by means of the
finest threads that could be got, estimates of the distance between the
pairs were made at Flagstaff in 1905, and the results agree as closely
as the means permit with those got by measurement of the doubles as
depicted in the drawings.
[Illustration: Martian doubles.]
Of what they look like, the following illustrations give a fair idea,
only that instead of being more geometrically regular in the drawing
than in reality the fact is the other way. Freehand draftsmanship at
the telescope is incapable of rendering their ruled effect. No railway
metals could be laid down with more precision. As to their size, the
following figures derived from a typical double canal, the Phison, give
some conception. This great artery of intercommunication between the
Sabaeus Sinus and the Nilosyrtis is, roughly speaking, 2250 miles long;
the distance between the centres of the two constituents is about 130
miles, and each line is perhaps 20 miles in breadth, when at its
maximum strength. The pair follow, apparently, the arc of a great
circle from the Portus Sigaeus on the Mare Icarium to the Pseboas Lucus
in latitude 40° north. The Portus Sigaeus consists of two little nicks
in the coastline, looking like the carets one makes in checking off
items down a list, if the space between the down and up strokes were
then filled in; the Pseboas Lucus, on the other hand, is a large round
dot like a small ink spot. To these two differently appearing spots,
the twin lines of the Phison behave differently. While each line leaves
centrally its own caret of the Portus Sigaeus at the south, at the
north each touches peripherally the Pseboas Lucus, on the east and west
sides respectively, the two thus just holding the Lucus between them.
In position the lines are invariable, though in visibility not.
Sometimes only one is seen, sometimes both show faintly, and sometimes
both are conspicuously strong. The delicacy of the observations by
which this detail was established is second only to its importance. It
destroys at a stroke all possibility of diplopic unreality, since were
that the fact the Pseboas Lucus should be doubled, which it is not. At
the same time it opens vistas into the true construction of the things
themselves, at present more suggestive than satisfactory.
[Illustration: Martian doubles (corroborating the above).]
In the great circle character of its course the Phison is quite normal.
The majority of the double canals pursue the like method, running
straight over the surface from one point to another, the constituents
remaining equidistant throughout. But such forthrightness of direction,
though the rule, is not without exceptions. The Thoth-Nepenthes, for
example, sweeps round in a seemingly continuous curve to the
west-southwest from the Aquae Calidae to the Lucus Moeris like some
mighty bow perpetually bent. Nevertheless its lines are no less careful
for all their curving to keep their distance from one end to the other
of their course. The quality of being paired rises superior to change
of direction.
II
Now, the first point to be noticed about the doubles is that
bilateralism, or the quality of being double, is not a universal trait
of the canals, either actually or potentially; it is not even a general
one. Out of the four hundred canals seen at Flagstaff, only fifty-one
have at any time displayed the quality; that is, one eighth roughly of
the whole number observed. This point is most important; for the fact
is of itself enough to disprove any optical origin for the phenomenon.
The characteristic of doubling so confidently ascribed by those who
have not seen it to general optical or ocular principles proves thus
the exception, not the rule, with the canals, and by so doing disowns
the applicability of any merely optical solution. We shall encounter
many more equally prohibitive bars to illusory explanation before we
have done with the doubles, but it is interesting to meet one in this
manner at the very threshold of the subject.
On the other hand, the characteristic when possessed is persistent in
the particular canal, _in posse_ if not _in esse_. Once shown by a
canal, that canal may confidently be looked to at a proper time to
disclose it again. In short, bilateralism, or the state of being dual,
is an inherent attribute of the individual canal, as idiosyncratic to
it as position and size.
The catalogue of canals possessing this property, so far as they have
been detected at Flagstaff to date, number fifty-one if we include in
the list wide parallels like the Nilokeras I and II. Eight of these
were observed in 1894; nineteen more were added in 1896, making
twenty-seven; in 1901 the total was raised to thirty; in 1903 to
forty-eight; and in 1905 to fifty-one. Arranged by years they are
tabulated below, where the numeral to the left registers for each its
first recording and the position held by it in the list. The starred
canals much exceed the others in width, and possibly denote a different
phenomenon.
DATE CONFUSED
1894
1. Ganges
2. Nectar
3. Euphrates
4. [*]Nilokeras I and II
5. Phison
6. Asopus
7. Jamuna
8. Typhon
1896-7
Ganges Typhon
Euphrates Avernus S.
Phison
9. Lethes
Jamuna
10. Dis S.
11. Titan
12. Laestrygon
13. Tartarus
14. Cocytus
15. Sitacus
16. Amenthes
17. Adamas
18. Cerberus N.
19. Cerberus S.
20. Cyclops
21. Gelbes
22. Erebus
23. Avernus N.
24. Gigas
25. Alander
26. Gihon
27. Hiddekel
1900-1
Phison Dis S.
Euphrates Boreas
Hiddekel Cerberus S.
Amenthes Jamuna
Cerberus N. Pyramus
Cyclops Laestrygon
Ganges
28. Deuteronilus
Sitacus
Adamas
29. Djihoun
Gihon
30. Is
1903
Djihoun Typhon
Hiddekel Orontes
Phison
Euphrates
31. Protonilus
Gihon
32. Marsias
Amenthes
Laestrygon
Cyclops
Gigas
*Nilokeras I and II
Ganges
Deuteronilus
33. Pierius
34. Callirrhoe
Jamuna
Sitacus
35. Astaboras S.
36. Nar
37. Chaos
38. Aethiops
39. Hyblaeus
40. Eunostos
41. Thoth
42. Nepenthes
43. Triton
44. Pyramus
45. Fretum Anian
46. Vexillum
Lethes
Cerberus S.
47. Nilokeras I
Cerberus N.
48. Tithonius
1905
Nilokeras Ganges
Hiddekel Chrysorrhoas
Djihoun
Sitacus
Phison
Euphrates
Amenthes
Vexillum
Astaboras S.
Adamas
Cyclops
Cerberus S.
Cerberus N.
Tartarus
49. [*]Propontis
Gigas
Gihon
Nepenthes
Thoth
Laestrygon
50. Polyphemus
Deuteronilus
Triton
Eunostos
Tithonius
Callirrhoe
Pyramus
Nar
Protonilus
51. Naarmalcha
In spite of possessing the property of pairing, a canal may not always
exhibit it. To the production of the phenomenon the proper time is as
essential as the property itself. So far as a primary scanning or first
approximation is capable of revealing, a canal will be single at one
Martian season and double at another. Thus these canals alternated in
their state to Schiaparelli and for the earlier of his own observed
oppositions to the writer. In consequence Schiaparelli deemed
gemination a process which the canal periodically underwent. Three
stages in the development were to him distinguishable: the single
aspect, a short confused aspect, and the clearly dual one.
In the single state the canal remained most of the time. It then
underwent a chrysalid stage of confusion to emerge of a sudden into a
perfect pair. Furthermore, he noted the times at which the pairing took
place, to the formulating of a law in the case—derived from the
observations of more than one opposition. His law was that the
gemination occurred, on the average, three months (ours) after the
summer solstice of the northern hemisphere, lasted four to five months,
then faded out to begin afresh one month after the vernal equinox of
the same hemisphere and continue for four months more. Expressed in
Martian seasonal chronology, the periods would be about half as long.
At certain times then the most pronounced specimens of doubles showed
obstinately single, while the periodic metamorphosis that transformed
them into duplicates was timed to the changes of the planet’s year.
Gemination, then, was a seasonal phenomenon.
Advance in our knowledge of the phenomenon since Schiaparelli’s time,
while still showing the thing to be of seasonal habit, has changed our
conception of it. It now appears that in some cases certainly, and
possibly in all, the dual aspect is not a temporary condition, but the
differing pronouncement of a permanent state, the fact of gemination so
called being confined to a filling out of what is always skeletonly
there. As the canals have come to be better seen, the three stages of
existence have in some cases become recognizable as only different
degrees in discernment of an essential double condition; the single
appearance being due to the relative feebleness of one of the
constituents and the confused showing to the weakness of both, which
are then the more easily blurred by the air waves. In certain canals
the last few oppositions, 1901, 1903, and 1905, have disclosed this
unmistakably to be the case, as with the Phison and Euphrates, for
example. With them the double character has been continuously visible,
appearing not only when by Schiaparelli’s law it should, but at the
times when it should not; only on these latter occasions it was harder
to see, whence the reason it was previously missed. So that further
scrutiny, while in no sense discrediting the earlier observations, has
extended to them some modification, and disclosed the underlying truth
to be the varying visibility, the thing itself, except for strength in
part or whole, persisting the same. Improvement in definition has
lowered the see-level to revelation of continuous presence of the dual
state. It is only on occasion that the improvement is sufficient for
the thing when at its feeblest to loom thus above the horizon of
certainty; yet at such moments of a rise in the seeing it is enough to
allow it to be glimpsed. Thus it fared with the Adamas at the
opposition of 1903, with the Gigas, and with many another in years gone
by. Separation has come with training and generally in the case of the
wider doubles, which leads one to infer that ease of resolution is
largely responsible for assurance of the permanency of the dual state.
Perplexing exceptions, however, remain, so that it is possible at
present only to predicate the principal of most of the double canals
but not of all. Leaving the exceptions out of account for the moment,
we pass to those general characteristics which are intimately linked
with what has just been said.
Inasmuch as the act of getting into a state antedates the fact of being
there, it is logical to let the description of the first precede. An
account of the process of gemination may thus suitably come before that
of its result.
Flux, affecting the double canals in whole or part, is the cause of the
apparent gemination. According as the flux is partitive or total is a
single or a dual state produced. At the depth of its inconspicuousness
the canal may cease to be visible at all; this occurs when both lines
fade out. On the other hand, the one line may outfade the other, and we
are presented with a seemingly single canal, at this its minimum
showing. In such seasons of debility the one line may appear and the
other not, or occasionally the other show and the one not, according to
the air waves of the moment. It is at these times that the double
simulates a single canal, and unless well seen and carefully watched
might easily masquerade successfully as such. The Hiddekel in the depth
of its dead season is peculiarly given to this alternately partitive
presentation. As the flux comes on, one or both lines feel it. If one
only we are likely to have a confused canal; if both, a difficult
double. The strength of the lines increases until at last both attain
their maximum, and the canal stands revealed an unmistakable pair, the
two lines paralleling one another in appearance as in position.
At the canal’s maximum and minimum the equality of its two constituents
is chiefly to be remarked, though it occurs on other occasions as well.
But, what is significant, when the two differ it is always the same one
that outdoes its fellow. It may be the right-hand twin in one pair, the
left-hand one in another; but whichever it be, for the particular canal
its preëminence is invariable. It is this canal which, except for
adventitious help or hindrance from the air-waves, alone shows when the
double assumes the seemingly single state. We may therefore call it the
original canal, the other being dubbed the duplicate. In some cases it
has been possible to decide which is which. It might seem at first
sight as if this point should always be ascertainable. But the
determination is more dilemmic than appears, not from any difficulty in
seeing the canal, but from the absence of distinguishing earmark at its
end. In a long stretch of commonplace coast, the precise point of
embouchure of a solitary canal cannot be so certainly fixed as to be
decisive later between two which show close together in the same
locality. It is only where some landmark points the canal’s terminal
that the problem admits of definite solution. This telltale tag may be
a bay like the Margaritifer Sinus, or double gulfs like the Sabaeus
Sinus, or portions of a marking not too large to permit of partitive
location like the Mare Acidalium, or a canal connection like the
Tacazze which prolongs the one line and not the other. In these and
similar instances the two lines become capable of identification, and
in such manner have been found those comprised in the following list:—
===================+===================+================
| | DATE OF
DOUBLE CANAL | ORIGINAL LINE | ASCERTAINMENT
-------------------+-------------------+----------------
Phison | The Eastern | 1894
Euphrates | The Western | 1894
Titan | The Western | 1896
Hiddekel | The Eastern | 1896
Gihon | The Western | 1896
Gigas | The Northwestern | 1896
Djihoun | The Western | 1901
Laestrygon | The Eastern | 1903
Nilokeras I and II | The Northern | 1903
Astaboras | The Southern | 1903
Jamuna | The Eastern | 1905
Ganges | The Western | 1905
===================+===================+================
In this list of originals the canals stand chronologically marshaled
according to date of detection. The Phison and Euphrates were the first
to permit of intertwin identification in 1894, while the Jamuna and
Ganges were the last to be added to the column in 1905. The list is not
long, though the time taken to compile it was. In the case of the
Ganges and the Jamuna, for example, although suspected for some time on
theoretic grounds, it was only at the opposition just passed that the
fact was observationally established. In his _Memoria_ V, Schiaparelli
has a list of similar detection, and if the present list be compared
with his, the two having been independently made, the concordance of
the result will prove striking, corroborative as it is of both. For the
necessary observations are very difficult.
Having thus realized the original by means of its superior showing, and
then identified it by its position, it is suggestive to discover that
the duplicate betrays its subordinate character, not only by its
relative insignificance, but by its secondary position as well. The
original always takes its departure from some well-marked bay,
seemingly designated by nature as a departure-point, or from a caret
belonging clearly to itself; the adjunct, on the other hand, leaves
from some neighboring undistinguished spot, as in the case of the
additional Djihoun, or makes use of a neighbor’s caret, as in the case
of the second Phison and the supplementary Euphrates. In either case it
plays something of the part of an afterthought; and yet the postscript
when finished reads as an integral part of the letter. An example will
serve to make the connection evident while leaving the character of the
connection as cryptic as ever.
In the long stretch of Aerial coastline bounding the Mare Icarium,
which sweeps with the curve of a foretime beach from the Hammonis Cornu
to the tip of the Edom Promontory, there stand halfway down its
far-away seeming sea-front two little nicks or indentations. Even in
poor seeing they serve to darken this part of the coast while in good
definition they come out as miniature caret-like bays. They are the
Portus Sigaei, and mark the spots where the Phison and the Euphrates
respectively leave the coast. About four degrees apart, the eastern
makes embouchure to the original Phison, the western to the original
Euphrates, and each in some mysterious manner is associated not only in
position but in action with the canal itself. In the single state each
canal leaves the Mare from this its own caret, the Phison proceeding
thence northeast down the disk, the Euphrates nearly due north, so that
starting four degrees apart at the south they are forty degrees asunder
at their northern termini. Clearly at these latter points they are not
even neighbors, and except for the accident of close approach at their
other ends have nothing in common anywhere. And yet when gemination
takes place a curious thing occurs: each borrows its neighbor’s
terminal as departure-point for its own duplicate canal. Having thus
got its base the replica proceeds to parallel its own original canal
without the least reference to the other canal whose own caret it has
so cuckoo-wise appropriated. What the Phison thus does to the
Euphrates, the Euphrates returns the compliment by doing to the Phison.
In this manner is produced an interrelation which suggests, without
necessarily being, an original community of interest; suggests it on
its face and yet appears to be rather of the nature of an adaptation to
subsequent purposes of a something aboriginally there.
[Illustration: _Mouths of Euphrates and Phison._
_June. 1903._]
That such latter-day appropriation is the fact is clearly hinted by the
behavior of another understudy of an original canal, in this case the
duplicate of the Djihoun, which in consequence of the position of its
original finds no neighboring embouchure already convenient to its use.
The single or original Djihoun leaves the tip of the needle-pointed
Margaritifer Sinus, which serves a like end to the Oxus and the Indus,
both single canals. The Sinus is itself a single bay, and so large that
for many degrees its shores on both sides converge smoothly to their
sharp apex. Because of this probably, the coast in the immediate
neighborhood is without canal connection, no canal being known along
either side till one reaches the Hydraotes at the Aromaticum
Promontorium, which marks the western limit of the gulf. The
consequence is that when the Djihoun doubles, the duplicate canal, not
having any terminus ready to its hand, has to make one for itself by
simply running into the Margaritifer Sinus, some distance up its
eastern side. It thus advertises its adjunctival character, and at the
same time the general fact that a neighbor’s terminus, though used from
preference, when convenient, is not an essential in the process.
Gemination occurs of its own initiative, but is conditioned by
convenience.
Whether one canal shows thus to the exclusion of the other, or whether
both stand so confused as not to be told apart, the fact remains that
the double is not always recognizable as such. If we turn to the list
of the doubles on page 222, we shall note that the same canals were not
always seen in the dual condition at successive oppositions. Some,
indeed, are so emphatically of the habit as to appear year after year
in a paired state, but others are not so constant to their
possibilities. Now, when it is remembered that at different oppositions
we view Mars at diverse seasons of its tropical year, we see that this
means that the phenomenon is seasonal; and furthermore that its
exhibition depends upon the canal’s position. Gemination, like the
showing or non-showing of the single canal, is conditioned by the place
of the canal upon the planet.
III
Turning from such generic characteristics to more specific traits, the
first thing to strike an attentive observer is that the doubles differ
in width; that they are not mensurably alike in the property they hold
in common of being paired. In some the twin lines are obviously farther
apart than in others, and the relation persists however repeated the
observations. Of two doubles the one will always surpass its fellow.
This contrasted individuality first struck me in the Phison and the
Euphrates; and from the first moment at which these doubles showed as
such. The Phison pair seemed perceptibly the narrower of the two. A
like distinction was evident at the next opposition and the next; in
fact, at every succeeding one to the present day. Nor was the
recognition of the fact confined to me. If we turn to Schiaparelli’s
Memoriae we shall find that that master had registered the same
idiomatic width for the two canals from first to last throughout his
long series of records. The observation thus made proved to apply to
each and all of these curious twins.
Diversity in width for different doubles appears plainly in drawings
where more than one double is depicted. As an example, two drawings are
here given in the text, made, the one on July 13, 1905, λ15°, and the
other on July 20, λ313°. In them the Phison, Euphrates, Djihoun, and
Thoth appear contrasted as unmistakably as either of them does with the
single canals apparent at the same time. That this drawing is typical
is borne out by all the best measures of the several doubles as seen at
successive oppositions, and marshaled in the subjoined list. How truly
individual the quality is stands proved by the relative values in
different years which are even more accordant than the absolute ones.
The canals were:—
=======================+=====================
| WIDTH
+------+-------+------
| 1903 | 1905 | MEAN
-----------------------+------+-------+------
1. Phison | 3.5 | 3.4 | 3.4
2. Euphrates | 4.0 | 4.2 | 4.1
3. [*]Protonilus | 2.8 | 2.0 | 2.4
4. Deuteronilus | 2.2 | 2.4 | 2.3
5. Pierius | 2.5 | -- | 2.5
6. Callirrhoe | 2.5 |[*]2.1 | 2.3
7. [*]Hiddekel | 3.8 | 4.9 | 4.3
8. [*]Gihon | 3.9 | 4.9 | 4.4
9. Djihoun | 2.0 | 1.9 | 1.9
10. Sitacus | 3.8 |[*]3.3 | 3.6
11. Jamuna | 4.5 | -- | 4.5
12. Ganges | 5.0 | 5.2 | 5.1
13. Nilokeras I and II | 11.0 | 11.7 | 11.3
14. Nilokeras I | 2.3 | -- | 2.3
15. Gigas | 3.5 | -- | 3.5
16. Laestrygon | 2.2 | -- | 2.2
17. Cerberus N. | 4.0 | -- | 4.0
18. Cerberus S. | 4.0 | -- | 4.0
19. Cyclops | 2.9 |[*]2.2 | 2.6
20. Nar | 2.6 | 2.0 | 2.3
21. Fretum Anian | 2.8 | -- | 2.8
22. Aethiops | 3.3 | -- | 3.3
23. Eunostos | 2.8 | -- | 2.8
24. Lethes | 2.9 | -- | 2.9
25. Marsias | 3.2 | -- | 3.2
26. Hyblaeus | 3.0 | -- | 3.0
27. Amenthes | 3.2 | 3.5 | 3.3
28. Thoth | 2.8 | 2.3 | 2.5
29. Nepenthes | 2.8 | 2.3 | 2.5
30. Triton | 2.7 |[*]2.3 | 2.5
31. Pyramus | 2.9 |[*]2.0 | 2.5
32. Astaboras S. | 3.2 | 3.1 | 3.1
33. Tithonius | 2.6 | 2.2 | 2.4
34. Vexillum | 3.5 | 2.9 | 3.2
35. Tartarus | -- | 2.7 | 2.7
=======================+======+=======+======
[*] Poor.
Here we have widths ranging from eleven degrees to two. The widths
given are those when the canal was at or sufficiently near its full
strength, and are measured from the centres of the constituents. We
notice two points: the agreement of the same canal with itself and its
systematic disagreement with others. But what is especially to the
point, if we compare the values found at successive oppositions, we
find that for different canals the values agree in their difference.
This shows that each of these values is, in most cases if not in all, a
norm for that particular canal; a value distinctive of it and to which
it either absolutely or relatively conforms. In other words, the width
of the gemination is a personal peculiarity of the particular canal, as
much an idiosyncrasy of it as its position on the planet.
Two general classes may be distinguished; those up to about five
degrees in width apart and those above this figure. Whether such very
widely separated lines as go to make up the second class, such as the
Nilokeras I and II, constitutes a double is a debatable point.
Schiaparelli thought they did, and so classed them. To me it did not at
first occur so to consider them, and in some instances, such as the
Helicon I and II, later observations seem to justify the omission. With
the Nilokeras I and II the outcome seems the other way. The reasons for
distrust of a physical relation between the constituents is not so much
the distance separating them, nor any lack of parallelism, as the
self-sufficient manner in which they show alone. Even this, however,
tends to be recognized in the narrower pairs as they come to be better
seen. It may be that width alone is wholly competent to selective
showing. For the farther apart two lines are on the planet, the more
opportunity is afforded the air waves to disclose the one without the
other, a relative revelation which is constantly happening to detail in
different parts of the disk. As long as any doubt exists of a physical
community of interest, it seems best to distinguish such possibly
merely parallel canals by suffixed numerals.
Of this class of doubles is the Nilokeras I and II. So wide is it that
Mr. Lampland succeeded in photographing it as such, the two
constituents showing well separated, and if it prove a true double it
will be the first Martian double to leave its impress on a sensitive
plate. Although separated by four hundred miles of territory, the two
lines are parallel so far as observation can detect, which, of course,
is not so very easy with the lines so far apart. In the country between
one crosswise canal certainly lies, the Phryxus, and much shading thus
far unaccounted for. Recent discoveries, however, point to the cause of
such shading as lines imperfectly seen. For in some cases the lines
have actually disclosed themselves, and warrant us in believing that it
is only imperfect seeing that keeps the others hid. Of the pair the
Nilokeras I is itself double, curiously reproducing what sometimes is
seen in the case of double stars, one of whose components turns out to
be itself a binary. The second line of the Nilokeras I lies close to
its primary on the north, and was on the only occasion of its detection
the merest of gossamers, while the Nilokeras I itself stood out strong
and dark. Thus do these Martian details increase and multiply in
intricacy the better the seeing brings them out.
In the case of the other doubles, the doubles proper so to speak, there
is every indication of a physical bond between the pair. What that bond
may be is another matter and seems to be of different divulging,
according to the particular instance. At one end of the subject, both
as the widest of these doubles and one of the most important, stands
the Ganges. The components of the canal are 5°.1 apart. This great
width, joined to the fact of scant extension, gives the canal a stocky
aspect, its breadth being but one sixth of its length. Its width draws
attention to it while the phenomena it exhibits intrigue curiosity.
As early as the first opposition of my observations in 1894, the canal,
as it underwent the process of doubling, showed phases of peculiarity.
It was first caught by me as a double over toward the terminator, or
fading edge of the disk; then as it was brought nearer the centre by
the gaining upon the longitudes, showed as a broad swath of shading of
a width apparently equal to any it later exhibited. In this appearance
it continued for some months, and then in October began to show a
clarification toward the centre. Once started, the lightening of its
midway advanced till at last, on November 13, it stood out an
unmistakable double, the two lines standing where the edges of the
swath had previously been. Had the observations here been all that one
could wish, the method of gemination would have been certain and of
great interest. Unfortunately, the observations left much to be
desired, and those repeated in 1896-1897 and 1901 were of like
doubtfulness. A period of swarthy confusion preceded the plainly dual
state, but whether the double simply clarified or widened as well it
was not possible to assure one’s self. That the canal exhibited plainly
the effects of seasonal development was as unmistakable as the steps
themselves were open to ambiguity. In 1903 the canal was at its minimum
and hardly to be made out. It seemed then to show an actual change in
width coincident with alteration of visibility. But this, too, could
not be predicated with certainty. It was also surmisable that the
westernmost line was the one from which the development proceeded.
In 1905 much more was made out about it, training in the subject and
increased proximity of the planet contributing to the result. It now
became clear to me that the canal did develop from the western side;
for the western edge made a dark line of definite boundary from which
shading proceeded to the eastern side, where it faded almost
imperceptibly off with no defined line to mark its limit. That this
shading gradually darkened was evident, but that when it could be seen
at all it extended to the extreme limit of the eventual double,
restricted the character if not the fact of an actual widening. At this
opposition, too, the canal passed through its period of minimum
visibility and was then seen, whenever it could be caught, as a
confused swath of full width. In the case of this canal, then, a
widening in the sense of a bodily separation of two lines seems
inadmissible. On the other hand, the gradual darkening of the swath,
and especially the advance of the darkening from the western side,
points to an interesting process there taking place.
[Illustration: Peculiar development of the Ganges.]
At the opposite end of the series stands the Djihoun. As the Ganges is
the widest of the instantly impressive doubles, so the Djihoun is the
narrowest the eye has so far been able to make out. Only two fifths of
the width of the Ganges pair, this slender double is very nearly at the
limit of resolvability. So well proportioned are its lines to the space
between them, however, that in ease of recognition it surpasses many
wider pairs. In form, too, it is distinctive, turning by a graceful
curve the trend of the Margaritifer Sinus into the Lucus Ismenius. With
its fundamental branch—the northern of the two—it joins what is
evidently the main line of the Protonilus—also the northern one—to
the Margaritifer Sinus’s tip.
[Illustration: Djihoun, the narrowest double.]
It differs from the Ganges in some other important particulars besides
width. In its case no band of shading distinguishes it at any time. It
has always been two lines whenever it has been seen other than as a
single penciling; the only confusion about it being evidently our own
atmosphere’s affair. These two lines, furthermore, have showed, within
the errors of observation, always the same distance apart. So that not
only no change of intercommunication between the lines but no change in
their places apparently occurs.
Between these extremes in width, two hundred miles more or less for the
Ganges and seventy-five miles for the Djihoun, the distance parting the
pairs of most of the double canals lies. From 3° to 3°.2 on the planet
may be taken as that of the average; the degrees denoting latitudinal
ones on the surface of Mars, the length of which is equal to
thirty-seven of our English statute miles.
Most of the canals conform apparently to the type of the Djihoun rather
than to that of the Ganges. Careful consideration of them fails to find
any increase or decrease of distance, between the pairs of the same
canal at different times, which cannot be referred to errors inevitable
to observation of such minute detail. In short, the double is made by
the addition of a second line in a particular position and not by a
growth out to it of a line coincident to begin with with the first.
I have said that the average width between the two lines of the doubles
was about 3°. It must not be supposed that this average width denotes
anything more than an average; or, in other words, that it denotes
anything in the nature of a norm. The remark is important in view of a
suggestion which I have heard made that we have here a system based on
fundamental Martian units, in which, or in multiples of which, the
dimensions of the canals are implicitly expressed. Such, however, does
not seem to be the case. In some instances, indeed, we have certain
evidence to the contrary and that the width of the double is
conditioned solely by antecedent place. The Phison and Euphrates offer
a case in point. These two important arteries in duplicate leave, as we
saw, from two carets in the Mare Icarium, the Portus Sigaei, held in
common tenancy by both. Each pair then proceeds down the disk inclined
at its own particular angle to the meridian in order to reach by a
great circle course a certain spot; the Pseboas Lucus in one case, the
Luci Ismenii in the other. As one of these angles is thirty-five
degrees while the other is only three, they must, from the
circumstances of their setting out, have not only different widths, but
widths determinately different in advance, since each is, roughly
speaking, foreshortened by the degree of divergence from the meridian.
The one, therefore, must be about four degrees to the other’s something
less than three and a half. This is what they actually are as
determined by measurement from observation. That the calculated value
agrees with that found from observation helps certify to a community of
starting-points, but it completely does away with comprehensive design
in the question of their widths. For if the one were so settled, the
other could not be.
Indeed, the next example seems to deny it to both. This example occurs,
too, not far away from the scene of the first, in the twin bays of the
Sabaeus Sinus, from which depart, _mutatis mutandis_, the double
Hiddekel and the two Gihon. These twin gulfs bear so little imprint of
being other than natural formations, that they have been universally
and very likely quite rightly taken for such ever since Dawes
discovered them in 1859, long before things like canals were dreamed
of. It is strange that when the Hiddekel and the Gihon were found by me
to be double in 1897, with a branch of both leading from each bay, the
connection between the sceptically scouted doubles and the thoroughly
believed-in bays should have been apparent. For to link a ghost to
materiality, if it does not discredit the materiality, serves to
substantialize the ghost. Furthermore, it shows that in this case
neither the one double nor the other can have had its width engineered
on any preconceived scale, unless the twin bays be themselves so
accounted for. So that it seems useless to seek for cryptic standards
in the canals or to think to find them a measure of value from the fact
of their being a medium of exchange.
[Illustration: The Sabaeus Sinus, embouchure for the double Hiddekel
and Gihon.]
A third instance of the same thing in the case of the Ganges and the
Jamuna was proved at the last opposition after having long been
suspected without my being able to make sure of it. These instances,
taken in connection with the wide range of values in the widths
presented by different canals, serve to show that the distance between
the twin lines is an individual characteristic of the particular canal,
and further to point to its cause, in some cases certainly and possibly
in all, as topographical. The duplicate line makes a convenience of a
neighbor, and suits its distance from its fellow to friendly
feasibility. To cut a ‘canal’ to conform to the country seems logical
if not obligatory, and quite in keeping with the nomenclature of the
subject; but here the starting-point appears to be the only thing
considered—the canal once safely launched being left to shift, or
rather not shift, for itself.
IV
Topography thus introduced to our notice for its effect on the breadth
of the doubles proves upon inspection to be of extended application to
the whole subject. Examined for position these canals turn out to have
something to say for themselves bearing on the question of their origin
and office.
With regard to position, probably the first query to suggest itself to
an investigator to ask is of the direction in which they run. Is there
a preponderance manifest in them for one direction over another? Do
they show an inclination to the vertical, to the horizontal, or to some
tilt between? To answer this we may box the compass, and taking the
four cardinal points with the twelve next most important points between
for sectional division segregate the doubles according to their
individual trend. As we have no means of determining in which sense any
direction is to be taken,—if indeed it is not to be taken alternately
in each,—we get eight compartments into one or the other of which all
the doubles must fall. This they do in the following manner:—
S. & N., Laestrygon, [+]Fretum Anian, Aethiops, Amenthes,
Titan, [+]Dis, [+]Is 7
S. S. E. & N. N. W., [+]Gihon, Ganges, [++]Tithonius, Euphrates,
Adamas 5
S. E. & N. W., [+]Eunostos, Triton, Tartarus, Naarmalcha 4
E. S. E. & W. N. W., [+]Astaboras, Typhon, [+]Pierius 3
E. & W., [+]Nar, [+]Protonilus, [*]Propontis, [++]Nectar,
[+]Cocytus, [+]Chaos 6
E. N. E. & W. S. W. [+]Deuteronilus, [+]Callirrhoe, [+]Cerberus N.,
Cerberus S., [+]Sitacus, [+]Erebus 6
N. E. & S. W., [+]Djihoun, [*]Nilokeras I & II, [+]Avernus,
[+]Nepenthes, Gigas, [+]Alander, Polyphemus, [+]Gelbes,
[+]Marsias, [+]Pyramus, [+]Nilokeras I, Asopus 12
N. N. E. & S. S. W., Jamuna, Phison, [+]Hyblaeus, Cyclops,
Lethes, [+]Thoth, [+]Vexillum, [+]Hiddekel 8
--
51
[*] Wide canals.
[+] Northern hemisphere exclusively.
[++] Southern hemisphere exclusively.
No conclusively marked preponderance for one direction over another
manifests itself by this partitionment. Nevertheless, a certain trend
to the east of north, as against the west of north, is discernible.
More than twice as many doubles run northeast and southwest or within
forty-five degrees of this as do similarly northwest and southeast,
there being twelve of the latter and twenty-six of the former. That
this seems to mean something the nearly equal pairing of quadrantal
points goes to show. Thus:—
N. & S. and E. & W. inclined canals number 7 + 6 = 13
N. N. E. & S. S. W. and E. S. E. & W. N. W. inclined
canals number 8 + 3 = 11
N. E. & S. W. and S. E. & N. W. inclined canals
number 12 + 4 = 16
E. N. E. & W. S. W. and N. N. W. & S. S. E. inclined
canals number 6 + 5 = 11
-- -- --
33 18 51
a fairly equable division in direction. A trend to the westward would
be given a particle descending from the north to the equator by the
planet’s rotation, thus turning it southwesterly; and one to the west
to a particle travelling equatorwards from the south, turning it
northwesterly. As the doubles lie in the northern hemisphere, either in
whole or part, to the extent of 93%, this might account for the
preponderating tilt to the east of north and west of south exhibited by
them. It would correspond with the lines of flow.
To see whether this be so we will take only those double canals that
lie exclusively in the northern and southern hemispheres respectively,
and note those in the former that trend to the west of south as against
those that run to the east of it, and _vice versa_ in the southern. In
the northern the proportion of the westerly to the easterly ones is 17
to 4; in the southern, 1 to 0 the other way.
Of those whose course is common to both hemispheres we find for the
ratio of the southwesterly to the southeasterly 8 to 7. But the
proportion of the course of these canals in the two hemispheres is on
the side of this same ratio.
From their direction we now pass to consideration of their distribution
in longitude. It appears that some meridians are more favored than
others. The hemisphere which has the Syrtis Major for centre is more
prolific in them than its antipodes. From longitude 80° to 200° there
are ten doubles, from 200° to 320° twenty-four, and from 320° to 80°
seventeen; or, roughly, in the proportion of 2, 5, and 3. That this
distribution means anything by itself is doubtful; it is much more
likely to be a general topographical consequence of their distribution
in another direction, which proves to be highly significant and which
we shall now expose—that of latitude.
If we separate the surface into zones, each ten degrees wide, and count
the doubles found traversing in whole or part the several zones, we
find the following arrangement:—
Column Headings:
A = At Opposition of 1903 Alone
B = At All Oppositions so far observed at Flagstaff
===========================================================+=====+=====
Double Canals of Mars | |
arranged according to Latitude | A | B
-----------------------------------------------------------+-----+-----
| |
Between 30° S. and 20° S. Tithonius, Nectar, Laestrygon | 2 | 3
| |
Between 20° S. and 10° S. Jamuna, Ganges, Gigas, | |
Laestrygon, Cyclops, Titan, | |
Tartarus, Polyphemus, Tithonius| 7 | 9
| |
| |
Between 10° S. and 0° Jamuna, Ganges, Gigas, | |
Laestrygon, Cyclops, Cerberus | |
S, Aethiops, Lethes, Amenthes, | |
Triton, Phison, Euphrates, | |
Titan, Tartarus, Adamas, | |
Typhon, Vexillum, Asopus, | |
Naarmalcha, Polyphemus | 15 | 20
| |
Between 0° and 10° N. Gihon, Djihoun, Jamuna, Ganges, | |
Gigas, Laestrygon, Cerberus N, | |
Cyclops, Cerberus S, Eunostos, | |
Aethiops, Lethes, Amenthes, | |
Triton, Nepenthes, Phison, | |
Euphrates, Sitacus, Hiddekel, | |
Tartarus, Adamas, Asopus, | |
Typhon, Vexillum, Cocytus, Is, | |
Avernus N, Naarmalcha, | |
Polyphemus | 21 | 29
| |
Between 10° N. and 20° N. Gihon, Djihoun, Jamuna, Nilokeras| |
I and II[4], Nilokeras I, Ganges,| |
Gigas, Eunostos, Aethiops, | |
Lethes, Amenthes, Thoth, | |
Astaboras, Phison, Sitacus, | |
Euphrates, Hiddekel, Adamas, | |
Asopus, Gelbes, Avernus N, | |
Erebus, Naarmalcha, Vexillum, | |
Is, Dis | 18 | 26
| |
Between 20° N. and 30° N. Gihon, Djihoun, Jamuna, | |
Nilokeras I & II,[4] | |
Nilokeras I, Alander, Hyblaeus,| |
Lethes, Amenthes, Thoth, | |
Sitacus, Astaboras, Vexillum, | |
Phison, Euphrates, Hiddekel, | |
Adamas, Eunostos, Aethiops, | |
Gelbes, Avernus N, Naarmalcha, | |
Is | 17 | 23
| |
Between 30° N. and 40° N. Deuteronilus, Alander, Nar, | |
Marsias, Fretum Anian, | |
Amenthes, Thoth, Vexillum, | |
Phison, Euphrates, Hiddekel, | |
Adamas, Eunostos, Djihoun, | |
Gihon, Nilokeras I, Chaos, | |
Gelbes, Aethiops, Naarmalcha | 12 | 20
| |
Between 40° N. and 50° N. Fretum Anian, Pyramus, | |
Protonilus, Propontis[4] | 3 | 4
| |
Between 50° N. and 60° N. Callirrhoe, Fretum Anian, | 3 | 3
Pierius | |
| |
Between 60° N. and 63° N. Pierius, Callirrhoe | 2 | 2
===========================================================+=====+=====