With the carets something of the same sort seems to take place—if we

may consider as betokening a general law the fact that in 1894 the

carets at the mouths of the Phison and Euphrates developed before their

affiliated canals. But about them much less is yet known, and we must

be content to say that the observations of 1905 made at the opposite

season of the canal’s year seem to bear this out.

PART IV

EXPLANATION

CHAPTER XXVIII

CONSTITUTION OF THE CANALS AND OASES

As rational science does not rest content with raw results, it now

becomes obligatory, by marshaling the facts to suitable discussion, to

seek to find out what they mean. Now, so soon as we scan these

phenomena for some self-interpretation, we perceive one characteristic

of the lines which at once appears to direct us to their nature and

justifies itself as a signpost with increasing certainty as we read on.

This trait is the very simple yet most significant one of showing

intrinsic change: the lines alter in visibility with time. This primary

proclivity we do not even need the cartouches to establish. That the

lines change is palpable to any one who will watch them long enough.

Schiaparelli was struck by the fact early in his study of the planet,

and it forces itself on the notice of any careful observer who compares

his own observations with one another at intervals. But though the

cartouches are not needed to a first revelation of mutability, they

serve to certify and precise it to much further information on the

subject. For, that these changes are not extrinsic, that is, are not

caused by varying definition, distance, or illumination, they make

patent even to those who have never seen the things themselves by

disclosing respective differences of behavior in lines similarly

circumstanced optically. The change is therefore intrinsic, and the

question arises to what can such intrinsic change be due.

In searching for cause, attention is at once attracted by another

series of transmutations that manifests itself upon the disk, in the

orderly melting of the polar caps. For the existence of the two sets of

metamorphoses suggests the possibility of a connection between them.

The inference is strengthened when we note that not only are both

periodic, but that furthermore the period of the two is the same. Each

polar cap runs through its gamut of change in a Martian year; the

canals also complete their cycle of growth and decay in a Martian

twelvemonth. The only difference between the two is that each polar cap

has but one maximum and one minimum in the course of this time, while

most of the canals have two of each, though the maxima are not alike

nor the minima either.

Not only is the period of the two series of changes the same, but the

one follows the other. For the development of the canals does not begin

till the melting of the polar cap is well under way. Now, as the polar

cap disintegrates it gives rise, as we have seen, to a dark belt of

blue-green which fringes its outer edge and retreats with it as it

shrinks. This tells, directly or indirectly, of a product let loose.

After this belt has been formed the canals nearest to it proceed to

darken, then those a little farther off follow suit, and so the wave of

visibility rolls in regular routine down the disk. Here, then, at the

outset we have a chronic connection between the two phenomena, the

disintegration of the cap and the integration of the canals.

Of water we saw that the caps were undoubtedly composed, and to water,

then, let loose by the melting of the cap, we may inferably ascribe the

thaumaturgy in the development of the canals. But it is not necessary

to suppose that this is done directly. That the increased visibility of

the canals can be due to a bodily transference of water seems doubtful,

if for no other reason than the delay in the action. Considerable time

intervenes between the disappearance of the cap and the appearance of

the canals, except in the case of such as have been covered by it.

Transformation consequent upon transference, however, would account for

hesitancy. A quickening to vegetal growth would produce the counterpart

of what we see. If, set free from the winter locking up, the water

accumulated in the cap then percolated equatorward, starting vegetation

in its course, this would cause the increased visibility of the canals

and at the same time explain the seeming delay, by allowing for the

time necessary for this vegetation to sprout. This is certainly the

most satisfactory explanation of the phenomena.

Thus started, the vegetal quickening would pass down the planet’s

surface and give rise to what we mark as seasonal change. But, though

in one sense of seasonal character, a little consideration will show

that it would be quite unlike the seasonal change which we know on

earth.

Could we see our earth from some standpoint in space, we should mark,

with the advent of spring, a wave of verdure sweep over its face. If

freedom from cloud permitted of an unimpeded view, this flush of waking

from winter’s sleep would be quite evident and could be seen to spread.

Starting from the equator so soon as the sun turned north, it, too,

would travel northward, and, distancing the sun, arrive by midsummer

well into the arctic zone. Here, then, we should note, much as we note

it on Mars, a tint of blue-green superpose itself successively upon the

ochre ground; but the mundane and the Martian vegetal awakening would

differ in one fundamental respect; the earthly wave would be seen to

travel from equator to pole, while the Arian travels from pole to

equator. Though clearly seasonal in character, both of them, the

transformations would be opposite in action. Some other cause, then,

must be at work from what we are familiar with on earth. This other

cause is the presence or absence of moisture.

Two factors are necessary to the begetting of vegetal life, the raw

material and the reacting agent. Oxygen, nitrogen, water, and a few

salts make up the first desideratum, the sun supplies the second.

Unless both be present, the quickening to life never comes. Now, the

one may be there and the other not, or the other there and the one not.

On earth the material including water is, except in certain destitute

localities, always present; the sun it is that periodically withdraws.

Observant upon the return of the sun is therefore the annual recurrence

of vegetal growth.

On Mars, on the contrary, water is lacking. This we now know

conclusively from other phenomena the disk presents which have no

connection with the present investigation and are, therefore,

unprejudiced witnesses to the fact. No permanent bodies of water stud

its surface. That the so-called seas are traversed by dark lines

permanent in place is one of several proofs of this. The only surface

water the planet knows comes from the melting of its polar caps.

Vegetation cannot start until this water reaches it. Consequently,

though the sun be ready, vegetation must wait upon the coming of the

water, and starting from near the pole follow the frugal flood

equatorward.

[Illustration: PHENOLOGY CURVES—EARTH.

* = Dead Point of Vegetation.

(From paper in _Proc. Amer. Phil. Soc._, by Percival Lowell.)]

[Illustration: PHENOLOGY CURVES—MARS.

* = Dead Point of Vegetation.

(From paper in _Proc. Amer. Phil. Soc._, by Percival Lowell.)]

Now, such contrariety of progression to what we should observe in the

case of the earth could we view it from afar is exactly what the curves

of visibility of the canals exhibit. Timed primarily, not to the return

of the sun but to the advent of the water, vegetal quickening there

follows, not the former up the latitudes but the latter down the disk.

For better understanding, the two curves of phenological quickening,

the mundane and the Martian, are shown in the diagrams. The plates

represent the surfaces of the two planets, that of the earth being

shown upside down with south at the top so as to agree with the

telescopic depiction of the topography of Mars. The stars mark the

epoch of the dead-point of vegetation at successive latitudes; the time

increasing toward the right. The curves, it will be noticed, are bowed

in opposite ways. The bowed effect is due in part to Mercator’s

projection; in part it may represent a real decrease in speed with

time. But what is strikingly noticeable is the opposite character of

the advance to the right, the one curve running up the disk, the other

down it. This shows that the development of vegetation proceeded in

opposite directions over the surface.

Thus is the opposed action upon the two planets accounted for, and we

are led to the conclusion that the canals are strips of vegetation fed

by water from the polar caps, and that the floral seasons there as

affecting the canals are conditioned, not as they would be with us,

directly upon the return of the sun, but indirectly so through its

direct effect upon the polar snows.

Once adventured on the idea of vegetation, we find that it explains

much more than the time taken by the wave of canal-development down the

disk. It accounts at once for the behavior of the canals in the three

northern zones: the polar, arctic, and sub-arctic. The mean cartouches

of these three zones dip down at their latter end instead of rising

there, as is the case with the cartouches of the mean canals farther

south. This dip denotes that the most northern canals were waning

already by the middle of their August, though the others showed no such

tendency; while the date of the deposition of the frost in these

northern latitudes shows that they were started upon their course

toward extinction before the snow itself had covered them. In other

words, they were not obliterated but snuffed out. That their decline

was thus preparatory to the coming of the first snowfall or frost-fall,

sufficiently severe to whiten the ground so that it did not melt the

next day, is suggestive of their constitution. It is clear that they

were not abruptly cut off by the frost, but were timed by nature to

such extinction. Vegetation would behave in just this way, since

evolution would accommodate the career of a plant to its environment.

The first question to present itself chronologically in the canals’

annual history is connected with the size of the cap. Unfortunately for

the simplicity of the phenomena, the cap is not an extensionless source

of flow, but an extended surface melting from the outer edge in. It

would seem, therefore, that water liberated from the outer parts should

have an effect before the main body of it were ready to begin its

general march down the disk. There should be, one would think, at least

a partial action, locally, before the main action got under way. Now,

there are certain canals that show cartouches increasing apparently

from the time observations began, and the most pronounced is the

Jaxartes, which lies of all the canals observed the farthest north.

Now, the cartouches were founded on canals quickened from the north

polar cap. The farther north the canal, therefore, the greater the

likelihood of its showing the phenomena.

That we note such canals is therefore not only not subversive, but

actually corroboratory, of the law it seems at first to shake. That all

the canals of these zones do not show a like cartouche-profile is not

necessary, a part of them being dependent, not upon the earlier, but

upon the later liberated flow, and thus partaking in the general law,

which grows uniform lower down the latitudes.

As the action from one polar cap proceeds, not only down to the

equator, but across it into the planet’s other hemisphere, it appears

that much, at least, of the surface of Mars has two seasons of vegetal

growth, the one quickened of the north polar cap, the other of the

southern. How far the polar spheres of action overlap it is not

possible at present to affirm, as the canals at this opposition were

only visible to 35° south latitude. That the north polar quickening

goes down so far is vouched for, and it is probable from other observed

phenomena that it goes farther.

The alternate semi-annual quickening also discloses itself directly in

the cartouches; the previous semestral growth from the south polar cap

actually showing in them before the impulse from the north began. The

slow falling of their curves to the minimum preceding their later rise

is nothing less than the dying out of the effect started six months

before from the south. The gentler gradient of their fall proclaims a

gradual lapse, just as the subsequent sharper rise points to the advent

of a fresh impulse. And this deduction seems to be borne out by another

circumstance. There is some evidence of decrease in the pre-minimal

gradient southward. This is telling testimony to the source whence the

impulse came. For if it originated at the south and traveled northward,

the southern canals would be the first to be affected and the first to

die out, and thus show a longer dead season, exhibited in the

cartouches as a more level stretch.

Lastly, the explanation of the canals as threads of vegetation fays in

with the one which has been found to meet the requirements of the

blue-green areas; while the fact that they prove to develop as they do,

reversely to what would take place on earth, is exactly what all we

have latterly learnt about the surface conditions of the planet would

lead us to expect.

From what has just been said we see that the latest observations at

Flagstaff confirm the earlier ones, and, what is especially

corroborative, they do so along another line. The former were chiefly

static, the latter kinematic. In other words, the behavior of the

canals in action bears out the testimony of their appearance at rest.

CHAPTER XXIX

LIFE

Study of the fundamental features of Martian topography has disclosed,

as we have seen, the existence of vegetation on the planet as the only

rational explanation of the dark markings there, considered not simply

on the score of their appearance momentarily, but judged by the changes

that appearance undergoes at successive seasons of the Martian year.

Thus we are assured that plant life exists on the planet. We are made

aware of the fact in more ways than one, but most unanswerably for that

trait to which vegetation owes its very name,—its periodic quickening

to life. Thus the characteristic which has seemed here most distinctive

of this phase of the organic, so that man even christened it in

accordance, has proved equally telltale there.

Important as a conclusion this is no less pregnant as a premise. For

the assurance that plant life exists on Mars leads to a further step in

extramundane acquaintance of far-reaching import. It introduces us at

once to the probability of life there of a higher and more immediately

appealing kind, not with the vagueness of general analogy, but with the

definiteness of specific deduction. For the presence of a flora is

itself ground for suspecting a fauna.

Of a bond connecting the two we get our first hint the moment we look

inquiringly into the world about us, that of our own earth. Common

experience witnesses to a coexistence which grows curious and

compelling as we consider it. For it is not confined to life of any

special order, but extends through the whole range of organisms of both

kinds from the lowest to the highest. Algæ and monera, orchid and

mammal, occur side by side and with a certain considerate poverty or

richness, as the case may be. Luxuriance in the one is matched by

abundance in the other; while a scanty flora means a poor fauna. This

of which we have been aware in regions round about us from childhood

grows in universality as we explore. Wherever man penetrates out of his

proper sphere he finds the same dual possession of the land or the sea,

and a similar curtailing or expanding of both tenantries together. No

mountain top so cold but that if it grow plants, it supports insects

and animals, too, after its kind; no desert so arid but that creeping

things find it as possible a habitat as life that does not stir. Even

in almost boiling geysers animalcula and confervæ share and share

alike. Only where extreme conditions preclude the one do they equally

debar the other.

Proceeding now from the fact to its factors we perceive reasons for

this tenure in common of the land by the vegetal and animal kingdoms.

Examination proves the two great divisions of the organic to be

inextricably connected. It strikes our notice first in the relation of

plants to animals. It is of everyday notoriety that animals eat plants,

though it is less universally understood that in the ultimate they

exist on nothing else. Plants furnish the food of animals; not as a

matter of partial preference but of fundamental necessity. For the

plant is the indispensable intermediary in the process of metabolism.

Without plants animals would soon cease to exist, since they are unable

to manufacture their own plasm out of the raw material offered by

inorganic nature. They must make it out of the already prepared plasm

of plants or out of other animals who have made it from plants. So that

in the end it all comes back to plant production. The plant is able to

build its plasm out of chemical substances; the animal cannot, except

in the case of the nitro-bacteria, begin thus at the lowest rung of the

alimentary ladder.

But the converse of this dependence is also largely true. Plants are

beholden to animals for processes that in return make their own life

possible. The latter minister to the former with unconscious service

all the time, and with no more arrogant independence than do our

domestics generally nowadays. The inconspicuous earthworm is the

fieldhand of nature’s crops, who gets his own living by making theirs.

Without this day and night laborer the soil for want of stirring had

remained less capable of grass. Above ground it is the same story.

Deprived of the ministrations of insects many kinds of plants would

incontinently perish. By the solicited visits of bees and other

hymenoptera—what generically may be classed by the layman as

flutter-bys—is the plant’s propagation made possible. Peculiarly well

named, indeed, are the hymenoptera, seeing that they are the great

matrimonial go-betweens, carrying pollen from one individual to another

and thus uniting what otherwise could not meet. Spectacular as this

widespread commerce is, it forms but portion of the daily drama in

which animals and plants alike take part. From forthright bargainings

of honey for help, we pass to less direct but no less effective

alliance where plants are beholden to animals for life by the killing

of their enemies or the weeding-out of their competitors, and from this

to generic furtherance where the interdependence becomes broadcast. In

the matter of metabolism the advantage is not all upon one side. In the

katabolic process of that which each discards are the two classes of

life mutually complimentary,—the waste of the one being the want of

the other,—carbonic acid gas being given off by the animal, oxygen by

the plant. In biologic economy it is daily more demonstrable that both

are necessary constituents to an advancing whole, and that each pays

for what it gets by what it gives in return.

That they are thus ancillary as well as coexistent today leads us to

confront for them a community of origin in the past; and further study

confirms the inference. Both paleontology and entomology, or the

science of the aged and the science of the young, prove such ancestry

to be a fact. By going back from the present into the past, or, what

amounts to substantially the same thing, by descending in the scale of

life to the lowest known forms of organism, we find proof of

concomitance, cogent because congenital. At the time when inorganic

chemical compounds first passed by evolution into organic ones, the

change was of so general a character that even such tardy

representatives of it as survive today tax erudition to tell to which

of the two great kingdoms they belong, the vegetal or the animal.

Simplest and most primitive of known organisms are the chromacea,

unnucleated single cells as Haeckel has shown, and next to them in

order come many of the bacteria, also of simple unnucleated plasm. So

little do the majority of the bacteria differ morphologically from the

chromacea, that on the score of structure the two are not to be

catalogued apart. Both are as elemental as anything well can be, which

only their diet serves to divide. Each is an organism without organs,

thus belying the dictionary definition of both animals and plants.

Etymologically they are not organic yet manifestly are alive, and only

in their action are unlike. The chromacea are plasm-forming beings, and

therefore they are plants; the bacteria are plasm-eating beings, and so

are animals. Even this distinction is not always preserved. As Haeckel

tells us: “the nitro-bacteria which dwell in the earth having the

vegetal property of converting ammonia by oxidation into nitrous acid

and this into nitric acid, using as their source of carbon the carbonic

acid gas of the atmosphere. They feed, like the chromacea, on simple

inorganic compounds.” Here, then, we have, close to the threshold of

organic life, unorganized organisms, roughly speaking coeval and

differing in a sense but little, either of them, from inorganic

crystals; and yet the one is an animal, the other a plant. Progenitors

of the two great divisions of life, they were themselves concomitantly

evolved, either side by side or as offshoots both of a common stock.

Now, if the ancestors of the two great organic kingdoms were thus

simultaneously produced here, we are warranted in believing that they

would similarly be produced elsewhere, given conditions suitably alike.

In consequence, if we detect the presence of the one, we already have

an argument for inferring the other. Not to complete our syllogism

would be to flaunt a lack of logic in nature’s face.

Rationally viewed, then, the general problem of life in other worlds

reduces itself to a question of conditions. Since certain physical

results follow inevitably upon certain physical premises, if we can

assure ourselves of the proper premises we may look to nature for their

conclusion. _A priori_, then, the possibility of life becomes one of

habitat. If the environment be suitable life will ensue. What makes for

such a mediary _milieu_ is, like most cosmic processes, in its

fundamentals of interesting simplicity; for the production of a proper

nidus depends primarily upon the mere size of the body parentally

concerned. If a planet be big enough it will inevitably bring forth

life, because of conditions suitable to its generating; if too small it

will remain sterile to the end of time.

That size should be the determining factor whether a planet shall be

fecund or barren may seem at first thought strange. Yet that it is so

admits of no rational doubt. All that we see of bodies about us shows

its truth, and what we have learnt of cosmic process enables us in some

sort to discern why. In order for evolution, such as we mark it upon

the earth, to be possible, the parent body must have been at one time

at a high temperature, since only under great heat can the primal

processes occur. But for this generation of caloric the aggregate mass

of the particles, the falling together of which makes the planet, and

their stoppage its internal heat, must be large. The sun’s rays alone

are insufficient to cause the necessary temperature; the heat must come

from within, though it be helped from without. Even here the action is

abetted by a large body. For a planet to entrap the sun’s rays or even

to preserve its own internal warmth, an atmosphere is needed, and it

takes a large body to retain an atmospheric covering sufficiently long.

Yet without it not only would there be no suitable state, but no medium

in which organic or even inorganic reactions could go on. Lastly,

water, the essential nidus for the organism’s early stages, has its

presence similarly conditioned. For this, like the atmosphere, would

from a small body speedily vanish away. Thus the planet itself is the

life-producing body, although the sun furthers the process when once

begun.

That the needed substances are planetarily present, what we know of the

distribution of matter astronomically sufficiently attests. What we

find in meteorites shows that the catastrophe which preceded our

present solar system’s birth scattered its elemental constituents

throughout its domain, and thus when they came to be gathered up again

into planets that these must have been materially the same. The manner,

not the matter, then, is alone that about which we are concerned.

Now, if the mass of matter gravitating together to form a planet be

sufficient to produce the proper inorganic conditions, the organic must

follow as a matter of course. That the organic springs from the

inorganic is not only shown by what has taken place on earth, but is

the necessary logical deduction from its decay back into the inorganic

again. As Nägeli admirably observes: “The origin of the organic from

the inorganic is, in the first place, not a question of experience and

experiment, but a fact deduced from the law of the constancy of matter

and force. If all things in the material world are causally related, if

all phenomena proceed on natural principles, organisms which are formed

of and decay into the same matter must have been derived originally

from inorganic compounds.”

The original oneness of the two, the fact that the organic sprang from

the inorganic, is shown by the cousinly closeness of the lowest organic

with the highest inorganic substances. The monera are suggestive of

crystals in their uniformity of structure. Both are homogeneous or

approximately so. Again, both grow by taking from what they come in

contact with that which they find suitable and so add to their body by

homogeneous accretion. Finally, when grown too large for single life,

they part into similar crystals or split into identical cells. The

difference between the division of the crystal and the fission of the

cell is small in kind; much less than that later differentiation in

genesis into parthenogenesis and sexual reproduction. Yet here we

unhesitatingly trace an assured relationship. It were straining at a

gnat to swallow a camel to doubt it in the other.

Just as the two behave analogically alike in their own action, so do

they observe a like attitude toward nature. They thus point to their

common origin. The monera are resemblant of chemical compounds in their

superiority to external influences. To outward conditions of

temperature and humidity the chromacea are much as sticks and stones.

Some species may remain for long frozen in ice, Haeckel observes, and

yet wake to activity so soon as it thaws. Others may be completely

desiccated, and then resume their life when put in water after a lapse

of several years. Thus both in their deathlike lives and in their

living immortality the chromacea are close to inorganic things.

From preference, however, these lowest forms of life affect what to us

would be unbearable temperatures. Many of the chromacea live in hot

springs at temperatures of 123° to 176° Fahrenheit, in which no other,

that is, no higher, organism can dwell. This choice of habitat is in

line with the other details of their evolutionary career. For it, too,

is in keeping with the conditions of crystalline growth, halfway as it

were on the road to them; the forming of crystals beginning at a

temperature higher still. And we perceive from it that the passing of

the inorganic into the organic is brought about by a lowering of the

temperature of the parent planet. This again, is in line with the

evolution of chemical complexity. Let the heat become less, and higher

and higher chemical compounds, finally the organic ones, become

possible. That evolution is nothing else than such a gradually

increasing chemical synthesis is forced on one by study of the facts.

Once started, life, as paleontology shows, develops along both the

floral and the faunal lines side by side, taking on complexity with

time. It begins so soon as secular cooling has condensed water vapor to

its liquid state; chromacea and confervæ coming into being high up

toward the boiling-point. Then, with lowering temperature come the

seaweeds and the rhizopods, then the land plants and the lunged

vertebrates. Hand in hand the fauna and flora climb to more intricate

perfecting, life rising as temperature lowers.

We perceive then that, considered _a priori_, the possibility of life

on a planet is merely a question of the planet’s size; and then

pursuantly that the character of that life is a matter of the planet’s

age. But age again is a question of size. For the smaller its mass the

quicker the body cools, and with a planet, growing cold means growing

old. Within the bounds that make life possible, the smaller the body

the quicker it ages and the more advanced its denizens must be. Just

how far the advance goes we may not assert dogmatically in a given

case, since not relative age alone but absolute time as well is

concerned in it. It may be that nature’s processes cannot be hurried,

and that for want of time development may in part be missed. But from

general considerations the limit of the time needed seems well within

most planetary careers.

Now, the aspect of the surface of Mars shows that both these conditions

have been fulfilled. Mars is large enough to have begotten vegetation

and small enough to be already old. All that we know of the physical

state of the planet points to the possibility of both vegetal and

animal life existing there, and furthermore, that this life should be

of a relatively high order is possible. Nothing contradicts this, and

the observations of the last ten years have rendered the conclusion

then advanced only the more conclusive. Even the evidence of the past

state of the planet confirms that given by its present one. That with

us life came out of the seas finds its possible parallel in the fact

that seas seem once to have existed there, leaving their mark

discernible to-day. Life, then, had there as here the wherewith to

begin. That we find air and water in both shows that it had the means

to continue once begun. That it then ran a like course is further

witnessed by what we now detect. The necessary premises, then, are

there. More than this. One half of the conclusion, vegetal life, gives

evidence of itself.

CHAPTER XXX

EVIDENCE

Of the existence of animal life upon a far planet any evidence must, of

necessity, assume a different guise from what its flora would present.

Plant life should be, as on Mars we perceive it is, recognizable as

part and parcel of the main features of the planet’s face. In no such

forthright manner could we expect an animal revelation. The sort of

testimony which would render the one patent would leave the other

obstinately hid.

So long as animate life was in the lowest sense animal, it would not be

seen at all, though it were as widespread as the vegetal life all about

it. Reason for this lies in their receptive character. Plants are

fixtures; where they start they stay; while from the nature of their

food, derived directly from the soil and from the air, and conditioned

chiefly by warmth and moisture, like forms inhabit large areas and by

their massed effect make far impression. With animals it is otherwise.

They feed by forage, from beetle to buffalo, roaming the land for

sustenance. Thus, both for paucity of number and from not abiding in

one stay they must escape notice at a distance such that as individuals

they fail to show; to say nothing of the fact that the flora usually

overtop the fauna, and so help to hide the latter while appearing

itself distinct. Any far view of our earth gives instance of this. Seen

from some panoramic height, forest and moorland lie patently outspread

to view, yet imagination is taxed to believe them tenanted at all.

Unless man have marred the landscape not a sign appears of any living

thing. One must be near indeed to note even such unusual sights as a

herd of buffalo in the plains or those immense flights of pigeons, that

in former years occurred like clouds darkening the air. From the

standpoint of another planet, through any such direct showing animal

existence would still remain unknown.

Not until the creatures had reached a certain phase in evolution would

their presence become perceptible; and not then directly, but by the

results such presence brought to pass. Occupancy would be first

evidenced by its imprint on the land; discernible thus initially not so

much by the bodily as by the mind’s eye. For not till the animal had

learnt to dominate nature and fashion it to his needs and ends would

his existence betray itself. By the transformation he wrought in the

landscape would he be known. It is thus we should make our own far

acquaintance; and by the disarrangement of nature first have inkling of

man.

That it is thus we should betray ourselves, a consideration of man’s

history will show. While he still remained of savage simplicity, a mere

child of nature, he might come and go unmarked by an outsider, but so

soon as he started in to possess the earth his handicraft would reveal

him. From the moment he bethought him to till the ground, he entered

upon a course of world-subjugation of which we cannot foresee the end;

but he has already advanced far enough to give us an idea of the

process. It began with agriculture. Deforestation with its subsequent

quartering of crops signalized his acquisition of real estate. His

impress at first was sporadic and irregular, and in so far followed

that of nature itself; but as it advanced it took on a methodism of

plan. Husbandry begot thrift, and augmented wants demanded an

increasing return for toil; and to this desirable end systematization

became a necessity. At the same time gregariousness grew and still

further emphasized the need for economy of space and time. In part

unconsciously, man learnt the laws that govern the expenditure of force

and more and more consciously applied them. Geometry, unloosed of

Euclid, became a part of everyday life as insidiously as M. Jourdain

found that he had been talking prose. Regularity rules to-day, to the

lament of art. The railroad is straighter than the turnpike, as that is

straighter than the trail. Communication is now too urgent in its

demands to know anything but law and take other than the shortest path

to its destination. Tillage has undergone a like rectification. To one

used to the patchwork quilting of the crops in older lands the

methodical rectangles of the farms of the Great West are painfully

exact. Yet it is more than probable that these material manifestations

would be the first signs of intelligence to one considering the earth

from far. Our towns would in all likelihood constitute the next; and,

lastly, the great arteries of travel that minister to their wants.

Their scale, too, would render them the first objects to be observed.

Farming as now practiced in Kansas or Dakota gives it a certain

cosmical concern; fields for miles turning in hue with the rhythm of

the drilled should impress an eye, if armed with our appliances, many

millions of miles away.

Even now we should know ourselves cosmically by our geometrical

designs. To interplanetary understanding it is this quality that would

speak. Still more so will it tell as time goes on. As yet we are but at

the beginning of our subjugation of the globe. We have hardly explored

it all, still less occupied it. When we do so, and space shall have

become enhancedly precious, directness of purpose with economy of

result will have partitioned so regularly the surface of the earth as

to impart to it an artificiality of appearance, and it becomes one vast

coördinated expanse subservient entirely to the wants of its

possessors. Centres of population and lines of communication, with

tillage carried on in the most economic way; to this it must come in

the end.

Nor is this outcome in any sense a circumstance accidental to the

earth; it is an inevitable phase in the evolution of organisms. As the

organism develops brain it is able to circumvent the adversities of

condition; and by overcoming more pronounced inhospitality of

environment not only to survive but spread. Evidence of this thought

will be stamped more and more visibly upon the face of its habitat. On

earth, for all our pride of intellect, we have not yet progressed very

far from the lowly animal state that leaves no records of itself. It is

only in the last two centuries that our self-registration upon our

surroundings has been marked. With another planet the like course must

in all probability be pursued, and the older the life relatively to its

habitat the more its signs of occupation should show. Intelligence on

other worlds could then only make its presence known by such material

revelation, and the sign-manuals of itself would appear more artificial

in look as that life was high in rank. Given the certainty of

plant-life, such markings are what one would look to find. Criticism

which refuses to credit detail of the sort because too bizarre to be

true writes itself down as unacquainted with the character of the

problem. For it is precisely such detail which should show if any

evidence at all were forthcoming.

If, now, we turn our inquiry to Mars, we shall be fairly startled at

what its disk discloses. For we find ourselves confronted in the canals

and oases by precisely the appearances _a priori_ reasoning proves

should show were the planet inhabited. Our abstract prognostications

have taken concrete form. Here in these rectilineal lines and roundish

spots we have spread out our centres of effort and our lines of

communication. For the oases are clearly ganglia to which the canals

play the part of nerves. The strange geometricism which proves

inexplicable on any other hypothesis now shows itself of the essence of

the solution. The appearance of artificiality cast up at the phenomena

in disproof vindicates itself as the vital point in the whole matter.

Like the cachet of an architect, it is the thing about the building

that established the authorship.

Though the Earth and Mars agree in being planets, they differ

constitutionally in several important respects. Even to us the curious

network that enshrouds the Martian disk suggests handicraft; it implies

it much more when considered from a Martian standpoint.

CHAPTER XXXI

THE HUSBANDING OF WATER

That the canals and oases are of artificial origin is thus suggested by

their very look; when we come to go further and inquire into what may

be their office in the planet’s economy, we find that the idea in

addition to its general probability now acquires particular support.

For this we are indebted in part to study of their static aspect, but

chiefly to what has been learnt of their kinematic action.

Dearth of water is the key to their character. Water is very scarce on

the planet. We know this by the absence of any bodies of it of any size

upon the surface. So far as we can see the only available water is what

comes from the semi-annual melting at one or the other cap of the snow

accumulated there during the previous winter. Beyond this there is none

except for what may be present in the air. Now, water is absolutely

essential to all forms of life; no organisms can exist without it.

But as a planet ages, it loses its oceans as has before been explained,

and gradually its whole water supply. Life upon its surface is

confronted by a growing scarcity of this essential to existence. For

its fauna to survive it must utilize all it can get. To this end it

would be obliged to put forth its chief endeavors, and the outcome of

such work would result in a deformation of the disk indicative of its

presence. Lines of communication for water purposes, between the polar

caps, on the one hand, and the centres of population, on the other,

would be the artificial markings we should expect to perceive.

Now, it is not a little startling that the semblance of just such signs

of intelligent interference with nature is what we discern on the face

of Mars,—in the canals and oases. So dominant in its mien is the

pencil-like directness of the canals as to be the trait that primarily

strikes an unprejudiced observer who beholds this astounding system of

lines under favorable definition for the first time, and its

impressiveness only grows on him with study of the phenomena. That they

suggested rule and compass, Schiaparelli said of them long ago, without

committing himself as to what they were. In perception the great

observer was, as usual, quite right; and the better they are seen the

more they justify the statement. Punctilious in their precision, they

outdo in method all attempts of freehand drawing to copy them. Often

has the writer tried to represent the regularity he saw, only to draw

and redraw his lines in vain. Nothing short of ruling them could have

reproduced what the telescope revealed. Strange as their depiction may

look in the drawings, the originals look stranger still. Indeed, that

they should look unnatural when properly depicted is not unnatural if

they are so in fact. For it is the geodetic precision which the lines

exhibit that instantly stamps them to consciousness as artificial. The

inference is so forthright as to be shared by those who have not seen

them to the extent of instant denial of their objectivity. Drawings of

them look too strange to be true. So scepticism imputes to the

draughtsman their artificial fashioning, not realizing that by so doing

it bears unconscious witness to their character. For in order to

disprove the deduction it is driven to deny the fact. Now the fact can

look after itself and will be recognized in time. For that the lines

are as I have stated is beyond doubt. Each return of the planet shows

them more and more geometric as sites are bettered and training

improves.

Suggestive of design as their initial appearance is, the idea of

artificiality receives further sanction from more careful

consideration, even from a static point of view, on at least eight

counts:—

1. Their straightness;

2. Their individually uniform size;

3. Their extreme tenuity;

4. The dual character of some of them;

5. Their position with regard to the planet’s fundamental features;

6. Their relation to the oases;

7. The character of these spots; and, finally,

8. The systematic networking by both canals and spots of the whole

surface of the planet.

Now, no natural phenomena within our knowledge show such regularity on

such a scale upon any one of these eight counts, _a fortiori_ upon all.

When one considers that these lines run for thousands of miles in an

unswerving direction, as far relatively as from London to Bombay, and

as far actually as from Boston to San Francisco, the inadequacy of

natural explanation becomes glaring.

These several counts become more expressive of design the farther one

looks into them. Straightness upon a sphere means the following of an

arc of a great circle. The lines, then, are arcs of great circles. Now,

the great circle course is the shortest distance connecting two given

points. The canals of Mars, then, practice this economy; they connect

their terminals by the shortest, that is, other things equal, by the

quickest and least wasteful path. Their preserving a uniform width

throughout this distance is an equally unnatural feature for any

natural action to exhibit, but a perfectly natural one for an unnatural

agent. For means of communication for whatever cause would probably be

fashioned of like countenance throughout. Their extreme tenuity is a

third trait pointing to artificiality; inasmuch as the narrower they

are, the more probable is their construction by local intelligence.

Even more inexplicable, except from intent, is their dual character.

For them to parallel one another like the twin rails of a railway

track, seems quite beyond the powers of natural causation. Enigmatic,

indeed, from a natural standpoint, they cease to be so enigmatic viewed

from an artificial one; and this the more by reason of what has lately

been learnt of the character of their distribution. That they are found

most plentifully near the equator, where the latitudinal girth is

greatest, and thence diminish in numbers to about latitude 60°, where

they disappear,—and this not relatively to the amount of surface but

actually,—is very significant. It is quite incapable of natural

explanation, and can only be accounted for on some theory of design

such as lines of communication, or canals conducting water down the

latitudes for distribution. So that this distribution of the doubles is

in keeping with the law of development disclosed by the canals _en

masse_. Channels and return-channels the two lines of the pair may be,

but about this we can at present posit nothing. The relation may be of

still greater complexity, and we must carefully distinguish between

surmise and deduction.

The position of the canals, with regard to the main features of the

disk, has a cogency of its own, an argument from time. The places from

which the lines start and to which they go are such as to imply a

dependence of the latter upon the former chronologically. The lines are

logically superposed upon the natural features; not as if they had

grown there, but as if they had been placed there for topographic

cause. Those termini are used which we should ourselves select for

stations of intercommunication. For the lines not only leave important

geodetic points, but they travel directly to equally salient ones.

The connection of the canals with the oases is no less telltale of

intent. The spots are found only at junctions, clearly the seal and

sanction of such rendezvous. Their relation to the canals that enter

them bespeaks method and design. Centring single lines, they are

inclosed by doubles, a disposition such as would be true did they hold

a pivotal position in the planet’s economy.

The shape of the oases also suggests significance. Their form is round,

a solid circle of shading of so deep a tone as to seem black, although

undoubtedly in truth blue-green. Now, a circular area has this peculiar

property, that it incloses for a given length of perimeter the maximum

of space. Any other area has a longer inclosing boundary for the

surface inclosed. Considering each area to be made up of onion-like

envelops to an original core, each similar in shape to the kernel, we

see that the property in question means that the average distance for

points of the circular area from the centre is less than the same

distance for those of any other figure. This has immediate bearing on

the possible fashioning of such areas. For sufficient intelligence in

the fashioners would certainly lead to a construction, where the

greatest area could be attended to at the least expenditure of force.

This would be where the distance to be traveled from the centre to all

the desired points was on the average least; that is, the area would be

round.

But last and all-embracing in its import is the system which the canals

form. Instead of running at haphazard, the canals are interconnected in

a most remarkable manner. They seek centres instead of avoiding them.

The centres are linked thus perfectly one with another, an arrangement

which could not result from centres, whether of explosion or otherwise,

which were themselves discrete. Furthermore, the system covers the

whole surface of the planet, dark areas and light ones alike, a

world-wide distribution which exceeds the bounds of natural

possibility. Any force which could act longitudinally on such a scale

must be limited latitudinally in its action, as witness the belts of

Jupiter or the spots upon the sun. Rotational, climatic, or other

physical cause could not fail of zonal expression. Yet these lines are

grandly indifferent to such compelling influences. Finally, the system

after meshing the surface in its entirety runs straight into the polar

caps.

It is, then, a system whose end and aim is the tapping of the snow-cap

for the water there semiannually let loose; then to distribute it over

the planet’s face.

Function of this very sort is evidenced by the look of the canals.

Further study during the last eleven years as to their behavior leads

to a like conclusion, while at the same time it goes much farther by

revealing the action in the case. This action proves to be not only in

accord with the theory, but interestingly explanatory of the process.

In the first place, the canals have shown themselves, as they showed to

Schiaparelli, to be seasonal phenomena. This negatives afresh the

possibility of their being cracks. But furthermore, their seasonal

behavior turns out to follow a law quite different from what we know on

earth and betokens that they are indebted to the melting of the polar

cap for their annual growth, even more directly than to the sun, and

that vegetation is the only thing that satisfactorily accounts for

their conduct. But again this is not all. Their time of quickening

proceeds with singular uniformity down the disk, not only to, but

_across the equator_. Now, this last fact has peculiar significance.

So large are the planetary masses that no substance can resist the

strains due to the cosmic forces acting on them to change their shape

till it becomes one of stable equilibrium. Thus a body of planetary

size, if unrotating, becomes a sphere except for solar tidal

deformation; if rotating, it takes on a spheroidal form exactly

expressive, as far as observation goes, of the so-called centrifugal

force at work. Mars presents such a figure, being flattened out to

correspond to its axial rotation. Its surface, therefore, is in fluid

equilibrium, or, in other words, a particle of liquid at any point of

its surface at the present time would stay where it was, devoid of

inclination to move elsewhere.

Now, the water which quickens the verdure of the canals moves from the

neighborhood of the pole down to the equator as the season advances.

This it does, then, irrespective of gravity. No natural force propels

it, and the inference is forthright and inevitable that it is

artificially helped to its end. There seems to be no escape from this

deduction. Water flows only downhill, and there is no such thing as

downhill on a surface already in fluid equilibrium. A few canals might

presumably be so situated that their flow could, by inequality of

terrane, lie equatorward, but not all. As we see on the earth, rivers

flow impartially to all points of the compass, dependent only upon

unevenness of the local surface conditions. Now, it is not in

particular but by general consent that the canal system of Mars

develops from pole to equator.

From the respective times at which the minima take place, it appears

that the canal-quickening occupies fifty-two days, as evidenced by the

successive vegetal darkenings to descend from latitude 72° north to

latitude 0°, a journey of 2650 miles. This gives for the water a speed

of fifty-one miles a day, or 2.1 miles an hour. The rate of progression

is remarkably uniform; and this abets the deduction as to assisted

transference. The simple fact that it is carried from near the pole to

the equator is sufficiently telltale of extrinsic aid, but the

uniformity of the action increases its significance.

But the fact is more unnatural yet. The growth pays no regard to the

equator, but proceeds across it as if it did not exist into the

planet’s other hemisphere. Here is something still more telling than

its travel to this point. For even if we suppose, for the sake of

argument, that natural forces took the water down to the equator, their

action must there be certainly reversed and the equator prove a

dead-line to pass which were impossible.

CHAPTER XXXII

CONCLUSION

That Mars is inhabited by beings of some sort or other we may consider

as certain as it is uncertain what those beings may be. The theory of

the existence of intelligent life on Mars may be likened to the atomic

theory in chemistry in that in both we are led to the belief in units

which we are alike unable to define. Both theories explain the facts in

their respective fields and are the only theories that do, while as to

what an atom may resemble we know as little as what a Martian may be

like. But the behavior of chemic compounds points to the existence of

atoms too small for us to see, and in the same way the aspect and

behavior of the Martian markings implies the action of agents too far

away to be made out.

But though in neither case can we tell anything of the Bodily form of

its unit, we can in both predicate a good deal about their workings.

Apart from the general fact of intelligence implied by the geometric

character of their constructions, is the evidence as to its degree

afforded by the cosmopolitan extent of the action. Girdling their globe

and stretching from pole, to pole, the Martian canal system not only

embraces their whole world, but is an organized entity. Each canal

joins another, which in turn connects with a third, and so on over the

entire surface of the planet. This continuity of construction posits a

community of interest. Now, when we consider that though not so large

as the Earth the world of Mars is one of 4200 miles diameter and

therefore containing something like 212,000,000 of square miles, the

unity of the process acquires considerable significance. The supposed

vast enterprises of the earth look small beside it. None of them but

become local in comparison, gigantic as they seem to us to be.

The first thing that is forced on us in conclusion is the necessarily

intelligent and non-bellicose character of the community which could

thus act as a unit throughout its globe. War is a survival among us

from savage times and affects now chiefly the boyish and unthinking

element of the nation. The wisest realize that there are better ways

for practicing heroism and other and more certain ends of insuring the

survival of the fittest. It is something a people outgrow. But whether

they consciously practice peace or not, nature in its evolution

eventually practices it for them, and after enough of the inhabitants

of a globe have killed each other off, the remainder must find it more

advantageous to work together for the common good. Whether increasing

common sense or increasing necessity was the spur that drove the

Martians to this eminently sagacious state we cannot say, but it is

certain that reached it they have, and equally certain that if they had

not they must all die. When a planet has attained to the age of

advancing decrepitude, and the remnant of its water supply resides

simply in its polar caps, these can only be effectively tapped for the

benefit of the inhabitants when arctic and equatorial peoples are at

one. Difference of policy on the question of the all-important water

supply means nothing short of death. Isolated communities cannot there

be sufficient unto themselves; they must combine to solidarity or

perish.

From the fact, therefore, that the reticulated canal system is an

elaborate entity embracing the whole planet from one pole to the other,

we have not only proof of the world-wide sagacity of its builders, but

a very suggestive side-light, to the fact that only a universal

necessity such as water could well be its underlying cause.

Possessed of important bearing upon the possibility of life on Mars is

the rather recent appreciation that the habitat of both plants and

animals is conditioned not by the minimum, nor by the mean temperature

of the locality, but by the maximum heat attained in the region. Not

only is the minimum thermometric point no determinator of a dead-line,

but even a mean temperature does not measure organic capability. The

reason for this is that the continuance of the species seems to depend

solely upon the possibility of reproduction, and this in turn upon a

suitable temperature at the critical period of the plant’s or animal’s

career. Contrary to previous ideas on the subject, Merriam found this

to be the case with the fauna of the San Francisco Peak region in

northern Arizona. The region was peculiarly fitted for a test, because

of rising a boreal island of life out of a sub-tropic sea of desert. It

thus reproduced along its flanks the conditions of climates farther

north, altitude taking the part of latitude, one succeeding another

until at the top stood the arctic zone. Merriam showed that the

existence of life there was dependent solely upon a sufficiency of

warmth at the breeding season. If that were enough the animal or plant

propagated its kind, and held its foothold against adverse conditions

during the rest of the year. This it did by living during its brief

summer and then going into hibernation the balance of the time. Nature

in short suspended its functions to a large extent for months together,

enabling it to resurrect when the conditions turned.

Hibernation proves thus to be a trait acquired by the organism in

consequence of climatic conditions. Like all such it can only be

developed in time, since nature is incapable of abrupt transition. An

animal suddenly transported from the tropic to a sub-arctic zone will

perish, because it has not yet learnt the trick of winter sleeping.

While still characterized by seasonal insomnia it is incapable of

storing its energies and biding its time. But given time enough to

acquire the art, its existence is determined solely by the enjoyment of

heat enough at some season to permit of the vital possibility of

reproducing its kind.

Diurnal shutting off of the heat affects the process but little,

provided the fall be not below freezing at the hottest season. So much

is shown by the fauna of our arctic and sub-arctic zones, but still

more pertinently to Mars by the zones of the San Francisco Peak region,

since the thinner air of altitude, through which a greater amount of

heat can radiate off, is there substituted for the thicker one of

latitudinally equal isotherms. Here again with the diurnal as before

with the seasonal it is the maximum, not the mean, or, till low, even

the minimum temperature, that tells.

Now, with Mars the state of things is completely in accord with what is

thus demanded for the existence of life. The Martian climate is one of

extremes, where considerable heat treads on the heels of great cold.

And the one of these two conditions is as certain as the other, as the

condition of the planet’s surface shows conclusively. In summer and

during the day it must be decidedly hot, certainly well above any

possible freezing, a thinner air blanket actually increasing the amount

of heat that reaches the surface, though affecting the length of time

of its retention unfavorably. The maximum temperature, therefore,

cannot be low. The minimum of course is; but as we have just seen, it

is the maximum that regulates the possibility of life. In spite,

therefore, of a winter probably longer and colder than our own, organic

life is not in the least debarred from finding itself there.

Indeed, the conditions appear to be such as to put a premium upon life

of a high order. The Martian year being twice as long as our own, the

summer is there proportionately extended. Even in the southern

hemisphere, the one where the summer is the shortest, it lasts for 158

days, while at the same latitudes our own is but 90 days. This

lengthening of the period of reproduction cannot but have an elevating

effect upon the organism akin to the prolongation of childhood pointed

out by John Fiske as playing so important a part in the evolution of

the highest animals. Day and night, on the other hand, alternate there

with approximately the same speed as here, and except for what is due

to a thinner air covering reproduce our own terrestrial diurnal

conditions, which as we saw are not inimical to life.

In this respect, then, Mars proves to be by no means so bad a habitat.

It offers another example of how increasing knowledge widens the domain

that life may occupy. Just as we have now found organic existence in

abyssal depths of sea and in excessive degrees of both heat and cold,

so do we find from exploration of our island mountains, which more than

any other locality on earth facsimile the Martian surface, its

possession there as well.

Another point, too, is worth consideration. In an aging world where the

conditions of life have grown more difficult, mentality must

characterize more and more its beings in order for them to survive, and

would in consequence tend to be evolved. To find, therefore, upon Mars

highly intelligent life is what the planet’s state would lead one to

expect.

To some people it may seem that the very strangeness of Martian life

precludes for it an appeal to human interest. To me this is but a

near-sighted view. The less the life there proves a counterpart of our

earthly state of things, the more it fires fancy and piques inquiry as

to what it be. We all have felt this impulse in our childhood as our

ancestors did before us, when they conjured goblins and spirits from

the vasty void, and if our energy continue we never cease to feel its

force through life. We but exchange, as our years increase, the romance

of fiction for the more thrilling romance of fact. As we grow older we

demand reality, but so this requisite be fulfilled the stranger the

realization the better we are pleased. Perhaps it is the more vivid

imagination of youth that enables us all then to dispense with the

hall-mark of actuality upon our cherished visions; perhaps a deeper

sense of our own oneness with nature as we get on makes us insist upon

getting the real thing. Whatever the reason be, certain it is that with

the years a narration, no matter how enthralling, takes added hold of

us for being true. But though we crave this solid foothold for our

conceptions, we yield on that account no jot or tittle of our interest

for the unexpected.

Good reason we have for the allurement we feel toward what is least

like us. For the wider the separation from the familiar, the greater

the parallax the new affords for cosmic comprehension. That which

differs little yields little to the knowledge already possessed. Just

as a longer base line gives us a better measure of the distance of the

sun, so here the more diverse the aspects, the farther back they push

the common starting-point and furnish proportionately comprehensive

insight into the course by which each came to be what it is. By

studying others we learn about ourselves, and though from the remote we

learn less easily, we eventually learn the more. Even on the side,

then, that touches most men, the personal, the strangeness of the

subject should to the far-seeing prove all the greater magnet.

One of the things that makes Mars of such transcendent interest to man

is the foresight it affords of the course earthly evolution is to

pursue. On our own world we are able only to study our present and our

past; in Mars we are able to glimpse, in some sort, our future.

Different as the course of life on the two planets undoubtedly has

been, the one helps, however imperfectly, to better understanding of

the other.

Another, more abstract but no less alluring, appeals to that desire

innate in man to know about the cosmos of which he forms a part and

which we call by the name of science. Study of Mars responds to this

craving both directly by revelation of the secrets of another world and

indirectly by the bearing of what we thus learn upon our understanding

of the laws of the universe. For the facts thus acquired broaden our

conceptions in every branch of science. Some day our own geology,

meteorology, and the rest will stand indebted to study of the planet

Mars for advance along their respective lines. Already the most alert

of those professing them are lending ear to information from this

source, and such cosmopolitanism can but increase as the years roll on.

Today what we already know is helping to comprehension of another

world; in a not distant future we shall be repaid with interest, and

what that other world shall have taught us will redound to a better

knowledge of our own, and of that cosmos of which the two form part.

[Illustration: _Lowell Observatory._ MARS 1905.]

INDEX

_Adamas_, unmistakable double in 1903, 214.

_Aeria_, white in, 76;

ruddy color of, 148.

Air (see Atmosphere), 86;

necessity of, to life, 166, 167;

as important to astronomical calculations, 7.

Air-waves, 250, 251, 273.

Albedo, low, 162, 167.

Algæ, 349.

_Amenthes_, hibernation of, 317-324.

Animalcula, in almost boiling geysers, 349.

_Aonium Sinus_, two doubles suspected in, 242.

_Aquae Calidae_, 208, 253, 315.

Archæan age of the earth, 132, 133, 138.

Areography, 20-31;

beginning and progress of, 109;

three periods in, 24.

Arizona, 16;

in desert belt, 13;

plateau of, 18.

_Arnon_, convergent double, 240.

Artificiality, of canal system, 366, 368, 369, 370, 374;

of oases, 366, 371.

_Ascraeus Lucus_, 331;

embraced by the double Gigas, 257.

_Astaboras_, connection with Lucus Ismenius, 260-263.

Atmosphere, of Mars, 62, 63, 71, 78, 79, 87;

shown to exist, 80, 82, 83, 84, 163, 167;

rare, 85, 86, 162, 167;

effect on temperature, 80;

constituents of, 162, 164, 166, 168.

Autumn, length of Martian, in northern hemisphere, 35, 48;

in southern, 35, 48.

Axial tilt, 34, 36, 55, 155, 161;

determinations of, 34, 36, 155;

determines character of seasons, 34, 36;

effect of, on presentation of arctic and antarctic regions, 70;

effect of, on temperature of arctic and temperate regions, 88.

Bacteria, plasm-eating beings, 353.

Barometric pressure, 63, 85.

Beer, 23, 26, 109.

Bilateralism, 208;

inherent attribute of canals, 209.

Blue band, surrounding polar caps, 39, 40, 42, 43, 56, 61, 63, 71,

161,

162, 168, 338, 339.

Blue-green areas (see Dark Regions), 32, 67, 163;

taken for seas, 110.

British Nautical Almanac, 35.

_Brontes_, development of, 304-312.

Cambrian era of Earth, 139.

Camera, the, 272;

advantage of, 273;

slower than the eye, 273;

stars the peculiar province of, 273, 274.

Canals, 11, 32, 163;

discovery of, 24, 26;

considered straits, 27;

regularity of, 28, 29;

unnatural in look, 173;

manner of introduction of, 174;

conditions necessary to seeing of, 174-177, 282, 283;

pencil-like lines, 177, 179, 367;

definite in direction, 178;

name, 180;

width of, 179, 180, 182;

length of, 183;

visible by virtue of length, 181;

oddities of, 183;

number of, 184;

systematic arrangement of, 184, 185, 187-191, 248;

connect with polar caps, 325, 339, 373;

import of system of, 338, 372, 373;

intrinsic change in, 283, 284, 337, 338;

what they are not, 185-187, 373;

zonal distribution of, 188, 189;

departure-points, 190;

dependent on general topography, 191;

of later origin than main features, 191, 247;

kinematic character of, 281-303;

effect on, of illumination, 284;

drawings of, numerous and

consecutive, 286;

coördination of data, 288, 289;

curves of visibility of (see Cartouches), 289, 290;

geometricism of, 175, 206, 365, 367, 368;

polar, 327.

Canals in the dark regions, 30, 31, 243-248;

of the southern hemisphere, 245;

of the northern hemisphere, 246, 247;

detection of, 243, 245;

deprived seas of marine character, 243;

part of canal system, 244, 245, 247.

Caps (see Polar Caps).

Carbon dioxide, 39, 161, 164-168.

Carbonic era of Earth, 134, 141, 142.

Carets, 265-270;

natural formations, 231, 232;

form and position of, 266, 267;

reason for shape of, 268;

associated with canals, 267, 269;

help in solution of riddle, 270;

act like oases, 333.

Cartouches of the canals, 289-303;

interpretation of, 291-293, 299-303, 344-347;

arranged by latitudes, 294;

showing first frosts, 299;

minimum points of, 297, 344;

maximum point of, 301;

mean canal, 297, 298.

Cenozoic times, 144.

_Cerberus_, obliterated by white spot, 75.

Change, 4, 281;

shown in polar caps, 37, 338;

in blue-green areas, 113, 114, 115, 120, 122-127, 163, 164;

in canals, 168, 169, 205, 283-285, 314, 337, 338;

in oases, 250-252, 330, 331, 337, 338.

Chromacea, 352;

plasm-forming beings, 353;

close to inorganic things, 357;

in hot springs, 357, 358.

_Chryse_, 90, 102.

Climate, 82-89;

one of extremes, 87;

temperature, theoretic and observed, 87;

non-glaciation the rule, 88.

Clouds, 55, 71, 73, 89, 163, 165, 283, 284;

but few exist, 83, 165;

none over blue-green areas, 92;

of tawny dust color, 106;

probably dust storms, 165;

prove existence of atmosphere, 167.

Cold, 87, 167, 299.

_Coloe Palus_, in connection with double canals, 257, 258, 263.

Color, 74, 148;

of Mare Erythraeum, 122.

Confervæ, in almost boiling geysers, 349, 358.

Cretaceous era of the earth, 136, 143, 151, 152.

Crystals, conditions of formation, 357.

Dana, 131, 139, 140.

Dark Regions, 122-125;

thought to be seas, 110, 111;

named in accordance, 110, 113;

change in aspect cast doubt on

marine character of, 113, 114;

change in, considered seasonal, 115, 120, 127, 163, 164;

marine character lost, 30, 115-118, 163, 164;

vegetation tracts, 119-127, 163, 164, 168, 169, 170;

below level of surrounding surface, 130, 164;

former ocean basins, 120, 129, 131;

latitudinal development in, 123, 124, 126, 127.

Dawes, 21, 23, 249, 250, 268.

Day, Martian, length of, 34, 160, 166.

Desert regions of the earth, 13, 149-155;

as observatory sites, 12, 13;

help explain Mars, 16, 17, 156;

color of, 149, 151;

compared with color of Mars, 150, 163;

vegetation in, 150;

position of, 153, 154;

due to winds, 154.

Desertism, 16, 89, 153-158.

Deserts (see Reddish-ochre regions).

_Deuteronilus_, 259-261.

Development of canals, latitudinal law of, 299, 302, 375;

follows melting of polar caps, 302, 338-340;

across equator, 373, 375.

Devonian era of the earth, 141.

Diaphragm, the great, 265.

Diplopia, 196.

_Djihoun_, narrowest double, 228-230;

embouchure of, 219-220;

connection with Luci Ismenii, 260, 262.

Double Canals, first seen by Schiaparelli, 28, 192;

impression of, 193, 204;

two classes of, 224;

require steady definition, 194;

phenomena of, 194, 205, 208, 212, 213;

physical bond between the constituents of, 226;

connection with bays, 232;

optical theories of, 196-203;

not illusions, 195-203, 209;

widths of, 205, 206, 221-224, 229, 230, 233;

length of, 205;

seasonal change in, 205;

constituents of, 204;

original line of, 216, 217;

number of, 205, 209;

list of, 210, 211;

gemination period of, 212, 213;

direction of, 234-236;

zonal distribution of, 236-239, 370;

distribution in longitude, 236;

tropical phenomena, 239, 240, 241, 242;

compared with single canals, 240;

convergent, 240;

avoid blue-green areas, 241;

connect with blue-green areas, 242.

Dust storms, 90, 165.

Earth, tilt of axis of, 34;

seasons on, 35;

polar caps of, 38, 41, 44, 45, 51, 54, 69;

rainfall on, 79;

viewed from space, 340;

vegetal quickening opposite to that on Mars, 344.

Eccentricity of orbit, effect on seasons, 46, 48, 52.

Elevations on limb, 96, 97;

measurement of, 98.

_Elysium_, white in, 75, 76.

Eocene era of the earth, 144.

Eopaleozoic era, 140.

_Euphrates_, 221, 231, 249, 258-261, 266, 267, 316;

continuously double, 213;

curious relation to the Portus Sigaeus and Phison, 218, 219.

Evolution, 362, 366, 367;

planetary, 363, 364;

advance in, dependent on environment, 145, 146.

Exploration, polar, 54.

Eye, relation to camera, 272-274.

Farms in Kansas and Dakota, 363.

_Fastigium Aryn_, 269;

origin of longitudes, 23, 74.

Fauna, 361;

of northern Arizona, 18;

linked with flora, 349, 350, 358.

Flagstaff, Arizona, 16.

Flammarion, 21, 23, 202.

Flora, 361;

linked with fauna, 349, 350, 358;

fixtures, 360.

Focal length, of objective in photographing canals, 275.

Franz Joseph Land, 45.

Frosts, first arctic, 299, 300, 345;

suggestive of, 87.

Galileo, 20, 39.

_Ganges_, 270;

peculiar development of, 226-228;

widest double, 228, 229.

Gemination, 214-221;

seasonal phenomenon, 212, 213;

conditioned by convenience, 218-221.

Geology, shows the growing of the land, 131-138.

_Gigas_, embracing the Ascraeus Lucus, 257.

_Gihon_, embouchure of, 232.

Gravitation, law of, 160.

Gravity, effect on atmosphere, 62;

force of, on Mars, 63.

Green, 21, 23, 24.

Habitability, 159.

Haeckel, 352, 353, 357.

Haze, at melting of caps, 56, 64-66, 90, 93, 165;

recurrent, 94.

Heat, 46, 47, 50, 146, 155.

_Hellas_, 81, 90, 91;

in winter, 58, 59;

ruddy color of, 148.

Herschel, Sir W., 34, 37.

Hibernation of canals, 313-324, 379.

_Hiddekel_, embouchure of, 232;

connection with Luci Ismenii, 260-262.

_Hippalus_, identical with rift, 326, 327.

Hoarfrost, 78, 79, 81;

at equator, 79;

in southern hemisphere, 80, 92.

Huyghens, 23, 26, 108.

Ice sheet, effect of, 52.

Illumination, oblique, 97;

for measuring elevations, 98.

Illusion theories of canals, disproved, 293.

Image of sun, not reflected from dark areas, 112.

Insolation, 47, 79, 91.

Intelligence on other worlds, method of making itself known, 364.

Islands south, 91, 244;

effect of, on isothermal lines, 92.

_Jamuna_, original line of, 216, 217.

_Jaxartes_, polar canal, 328.

Jupiter, 33, 372.

Jurassic era of the earth, 136, 143, 144.

_Juturna Fons_, a square oasis, 263.

Kaiser, 21, 23, 249.

Kinetic theory of gases, 83, 146, 147, 164.

_Kison_, convergent double, 240.

_Lacus Hyperboreus_, 246.

Lampland, 197, 225, 275.

Lick Observatory, 100.

Life, necessity of air and water to, 17, 166, 167, 341;

thin cold air no bar to, 18;

maximum temperature determinative of, 19, 378, 380.

Life on Earth, 349-353;

dependent on conditions, 349-355, 357, 379, 380.

Life on Mars, 169, 376;

vegetal, 348, 359;

probably of high order, 348, 359, 377, 378, 381, 382;

evidence of, 360-365.

Limb-light, evidence of atmosphere, 84, 162, 167.

Longitudes, origin of, 23, 74.

Lowell Observatory, Annals, 31, 81;

Bulletin, 201.

_Lucus Ismenius_, 19, 258;

only double oasis, 259;

association with canals, 260, 261.

_Lucus Lunae_, 330.

_Lucus Moeris_, 208.

Maedler, 21, 23, 26, 109.

Mammal, 349.

Maps, of Mars, 20-24, 26-29.

_Mare Acidalium_, 115, 242, 246-252;

white in, 80;

darker than the Mare Erythraeum, 127.

_Mare Cimmerium_, 267.

_Mare Erythraeum_, 113;

irregular lines in, 30;

in 1903, 122-124;

in 1905, 124-126.

_Mare Icarium_, 207.

_Mare Sirenum_, 92, 110, 114, 267.

Maria, on the moon, 109, 111;

not seas, 112, 113;

on Mars, 110;

not seas, 117;

southern hemisphere, 31.

Matter, distribution of, 355.

Mercator’s projection, 22, 344.

Merriam, 18, 19, 379.

Mesozoic times of the earth, 135, 142, 144, 151.

Meteorology of Mars, 63, 93.

Moisture, 86, 154.

Monera, 349, 357;

suggestive of crystals, 356.

Months, Martian, different from our own, 36.

Mountains, not visible on Mars, 100;

measurement of, 97-100;

limit of height visible, 100;

on Moon, 98, 99.

_Naarmalcha_, association with Luci Ismenii, 260, 261.

Nägeli, 356.

Nansen, 54.

Naval Observatory at Washington, 16.

_Nectar_, shows white, 59.

Neopaleozoic times of the Earth, 140.

Neptune, 33.

Nicks in the coastline (see Carets).

_Nilokeras_, double, 209;

photographed, 225.

_Nilosyrtis_, unlike other canals, 262.

Nitro-bacteria, 350, 353.

Nitrogen, 83, 164, 166, 341.

_Nix Olympica_, 74, 78.

North America, geologic history of, 133-137.

Oases, detected later than canals, 30, 249;

three stages in appearance of, 250-252;

number of, 252;

kinds of, 252-254, 263;

shape of, 253, 371;

position of, 254-257, 263;

connected with canals, 256, 257, 262, 371;

disprove diplopic theory, 258;

objectivity of, 263;

in dark regions, 163, 244, 263, 264;

kinematic character of, 330-333;

latitudinal progress of change in oases, 331;

evolution of, 331, 332;

intrinsic change in, 337, 338;

at junction of canals only, 255, 371.

Observations, mutual corroboration of, 165, 166;

among mountains, 7.

Organic Evolution, origin of, 356.

Orology, of Mars, 62.

Ovid, 25.

Oxygen, 83, 164, 166, 167, 341.

Paleozoic times on the Earth, 135.

Permian period, 142.

Personal equation, eliminated, 287.

Phenological quickening, on Earth, 342;

on Mars, 343.

_Phison_, 221, 231, 249, 258, 266, 267, 316;

continuously double, 213;

connection with Euphrates and Portus Sigaeus, 218, 219.

_Phœnix Lake_, 330.

Photographs of the canals, 225, 275-277.

Photography, celestial, 271-277.

Physiographic conditions, on Mars, 68, 128.

Pickering, W. H., 330.

_Pierius_, 71.

Polar caps, phenomena of, 37, 41, 61;

key to comprehension of planet, 37;

compared with those of earth, 41, 46;

composition of, 39, 161, 168, 339;

making of new, 94;

position of, 68;

aspect of, 56, 57;

maxima and minima of, 38, 41-44, 47-53, 55-57, 66-68, 162;

fission of, 61.

Polar seas (see Blue band);

fresh water, 162.

Poles, Martian, determination of, 36.

_Pons Hectoris_, 78.

_Portus Sigaeus_, nicks in the coastline, 207, 266, 267;

embouchure to Phison and Euphrates, 218.

Precipitation, 51, 79, 154, 155;

effect on glaciation, 52.

Presentation, a, defined, 287, 288.

Probability, law of, 160.

Projections on the terminator, 77, 81, 96, 100, 104, 165;

color of, 102;

cause of, 104-107;

great one of 1903, 101-104;

of 1900, 104.

_Propontis_, the, 242;

canals in, 247;

oases in, 256.

_Protonilus_, association with Luci Ismenii, 260.

_Pseboas Lucus_, 207, 250, 253, 263;

anomalous position of, 262.

Quaternary epoch of the Earth, 137.

Reddish-ochre regions, 153, 155;

deserts, 149, 156, 163;

variations of tint in, 32, 148, 149, 151.

Rifts in polar cap, 61-63, 67, 162, 325-329;

permanent in place, 61, 62;

not depressions, 62, 63, 162;

coincide with canals, 326-328;

explanation of, 328, 329.

Rotation, early noted, 108, 109;

how determined, 34;

time of, 34, 160;

disclosed by markings, 32-34, 108.

_Sabaeus Sinus_, 23, 207, 268, 269.

San Francisco Peaks, 18, 19, 149, 379, 380.

Saturn, 33.

Scepticism, 27, 28, 204.

Schaeberle, 30.

Schiaparelli, 11, 15, 21, 23, 24, 26, 27, 29, 30, 31, 34, 68, 74, 75,

81, 114, 115, 120, 121, 173, 177, 186, 192, 212, 217, 221, 247, 249,

265, 282, 313, 314, 325, 337, 367, 373.

Seas (see Dark Regions).

southern, 92;

formerly on Mars and the Moon, 129;

internal absorption of, 147.

Seasonal change, metabolic, 169;

in canals, 168, 169, 285, 373.

Seasons, like our own, 34, 35, 166;

length of, 48, 79, 161;

of vegetal growth, 346, 347.

Secular change, in canals, 314.

Silurian era of the Earth, 134, 138, 140.

Sky, blotting out of, 14;

measure of extinction of, 16.

Sky, Martian, 89;

clear, 165.

Slipher, 101, 103.

Snow, 345;

limits of, on Earth and Mars, 108.

_Solis Lacus_, 23, 242.

Spring, Martian, 35, 48;

haze in, 94.

S.S. Challenger, concerning south polar cap of earth, 45.

S.S. Pagoda, 45.

Subsidiary snow patches, 67, 73.

Summer, Martian, length of, 35, 48, 381.

Surface, relatively flat, 62, 76, 97, 164;

covered by canal network, 243;

clear-cut in good air, 258;

in fluid equilibrium, 374;

indicative of thin air, 162, 167.

Surface features, reality of, proved, 26, 33.

_Syrtis Major_, 22;

first marking made out, 23.

_Tempe_, white in, 77, 80.

Temperature, 78, 147, 165, 166;

effect on life, 358.

Terminator, projections on, 77, 81, 96, 100-107, 114, 165;

depressions on, 164.

Terrane, 108, 265.

Terraqueousness, shown by earth, 128, 131.

Terrestriality, follows terraqueousness, 129, 131, 137, 144-146;

earth’s oceans contracting in size, 131;

inevitably, 131, 146;

as shown by Mars and the Moon, 128, 130, 131;

as shown by the geologic history of earth, 131-137;

as shown by paleontology, 138-144;

making a better habitat, 145, 146.

Tertiary times of the Earth, 137, 151.

_Thoth-Nepenthes_, peculiar course of, 208;

hibernation of, 315-324.

_Titan_, 305.

Triassic era, 136, 142, 152.

_Trivium Charontis_, canals and oases in, 251, 252, 256.

Twilight arc, shows thin air, 85, 162.

Uranus, 33.

Vegetation, 79, 119-127, 163, 166, 169, 301;

color of Mare Erythraeum, 122-126;

proof of, 170;

theory supported by rifts in polar cap, 329;

most satisfactory explanation of phenomena of canals, 339, 341, 344,

345, 347, 348, 373;

two seasons of growth of, 346;

melts snow, 328.

Water, dearth of, 128, 161, 163, 166, 168, 169, 341, 366;

loss of, inevitable, 131;

speed of flow of, 375;

from polar caps, 340, 374.

Water-vapor, from polar caps, 83;

in atmosphere, 162, 168.

Weather, 66, 89, 95.

_Wedge of Casius_, 242;

canals in, 247;

oases in, 251, 252, 256.

Welkin, man-manufactured, 13-15.

White spots, 32, 165;

similar in look to polar caps, 73;

location and season of, 74, 76-79, 80, 81;

White spots, permanency of, 73, 76;

indication of temperature, 80, 165.

Winds, 154.

Winter, Martian, 35, 48.

World, Mars another, 4, 5, 169;

evolution of a, 16, 128, 131, 155-158, 358.

Year, of Earth, 35;

of Mars, 35, 161.

A COMPENDIUM OF SPHERICAL ASTRONOMY

With its applications to the determination and reduction of positions

of the fixed stars

By SIMON NEWCOMB

Cloth 8vo $3.00 net

--------------

CONTENTS

PART I. PRELIMINARY SUBJECTS

CHAPTER I. INTRODUCTORY. NOTES AND REFERENCES.

CHAPTER II. DIFFERENCES, INTERPOLATION, AND DEVELOPMENT. NOTES AND

REFERENCES.

CHAPTER III. THE METHOD OF LEAST SQUARES. Section I. Mean Values of

Quantities. II. Determination of Probable Errors. III. Equations of

Condition. NOTES AND REFERENCES.

PART II. THE FUNDAMENTAL PRINCIPLES OF SPHERICAL ASTRONOMY

CHAPTER IV. SPHERICAL COÖRDINATES. Section I. General Theory. II.

Problems and Applications of the Theory of Spherical Coördinates.

CHAPTER V. THE MEASURE OF TIME AND RELATED PROBLEMS. Section I. Solar

and Sidereal Time. II. The General Measure of Time. III. Problems

Involving Time.

CHAPTER VI. PARALLAX AND RELATED SUBJECTS. Section I. Figure and

Dimensions of the Earth. II. Parallax and Semi-diameter.

CHAPTER VII. ABERRATION.

CHAPTER VIII. ASTRONOMICAL REFRACTION. Section I. The Atmosphere as a

Refracting Medium. II. Elementary Exposition of Atmospheric

Refraction. III. General Investigation of Astronomical Refraction.

Notes and References to Refraction.

CHAPTER IX. PRECESSION AND NUTATION. Section I. Laws of the

Precessional Motion. II. Relative Positions of the Equator and

Equinox at Widely Separated Epochs. III. Nutation. Notes and

References to Precession and Nutation.

PART III. REDUCTION AND DETERMINATION OF POSITIONS OF THE FIXED STARS

CHAPTER X. REDUCTION OF MEAN PLACES OF THE FIXED STARS FROM ONE EPOCH

TO ANOTHER. Section I. The Proper Motions of the Stars. II.

Trigonometric Reduction for Precession. III. Development of the

Coördinates in the Powers of the Time. NOTES AND REFERENCES.

CHAPTER XI. REDUCTION TO APPARENT PLACE. Section I. Reduction to Terms

of the First Order. II. Rigorous Reduction for Close Polar Stars.

III. Practical Methods of Reduction. IV. Construction of Tables of

the Apparent Places of Fundamental Stars. Notes and References.

CHAPTER XII. METHOD OF DETERMINING THE POSITIONS OF STARS BY MERIDIAN

OBSERVATIONS. Section I. Method of Determining Right Ascensions. II.

The Determination of Declinations.

CHAPTER XIII. METHODS OF DERIVING THE POSITIONS AND PROPER MOTIONS OF

THE STARS FROM PUBLISHED RESULTS OF OBSERVATIONS. Section I.

Historical Review. II. Reduction of Catalogue Positions of Stars to a

Homogeneous System. III. Methods of Combining Star Catalogues.

NOTES AND REFERENCES

List of Independent Star Catalogues.

Catalogues made at Northern Observatories.

Catalogues made at Tropical and Southern Observatories.

APPENDIX

EXPLANATION OF THE TABLES OF THE APPENDIX.—I. Constants and Formulæ in

Frequent Use. II. Tables Relating to Time and Arguments for Star

Reductions. III. Centennial Rates of the Precessional Motions. IV.

Tables and Formulæ for the Trigonometric Reduction of Mean Places of

Stars. V. Reduction of the Struve-Peters Precessions to the Adopted

Values. VI. Conversion of Longitude and Latitude into R. A. and Dec.

VII. Refractions. VIII. Coefficients of Solar and Lunar Nutation. IX.

Three-place Logarithms and Trigonometrical Functions.

--------------

THE MACMILLAN COMPANY, 64-66 Fifth Avenue, New York

Transcriber's Notes

Ditto marks have been replaced by the text they represent.

Some presumed printer's errors have been corrected, including

normalizing punctuation. Further corrections are listed below:

Printed text Corrected text Page

MITGLIED DER MITGLIED DER

ASTRONOMISCHE GESELLSCHAFT ASTRONOMISCHEN GESELLSCHAFT Title page

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