by Mark Wicks
CHAPTER XX
THE SECRET OF THE "CARETS"--THE SUN AS SEEN FROM MARS
The next day, accompanied by Merna and Tellurio, we started off at anearly hour on an air-ship trip to the northern edge of the SinusTitanum.
This is really the bed of an ancient sea, from which all water has longsince disappeared. Nearly all the blue-green patches which are seen onthe planet by our observers are also old sea-beds, and they are now themost fertile areas upon its surface.
The object of our visit was to inspect the machinery and apparatus bywhich the water is lifted and forced along the canals; and rememberingwhat Merna had told him, M'Allister was looking forward to seeing themwith eager anticipation.
Professor Lowell has arrived at the conclusion that, owing to the shapeof the planet and other conditions, gravitation upon Mars is in a stateof stable equilibrium, and that consequently water would not flow bygravitation, as it does upon our earth, but merely spread out as itwould on a level floor. If turned into a canal it would not flow alongwithout artificial propulsion, except so far as it might be carried byits own "head."
We found, on inquiry, that this conclusion is very nearly correct, butthere is just a small amount of gravitation which is sufficient toproduce an extremely slow movement of the water in the canals.
_From a Globe made by M. Wicks_ Plate XII
MARS. MAP V.
The dark wedge-shaped area near the centre is "Syrtis Major." It was onthe desert area to the left of this that Professor Lowell discoveredseveral new canals on 30th September, 1909.]
I have already mentioned the discovery of the "carets" which exist incertain places on the planet. They are seen as small V-shaped markingswhich are dark in tint; and perhaps might better be described asresembling our Government's "broad-arrow," the central line representingthe end of a single canal which enters the caret centrally.
Professor Lowell is of opinion that these carets must fulfil someimportant purpose, as they only appear where some of the canals connectwith the dark areas of the old sea-beds. He is quite right in thisconclusion, for they are very important indeed in connection with theworking of the canal system.
They are, in fact, all situated on or adjoining the slopes of thesea-beds, and the dark sides of the V are really two high embankmentscovered with dense vegetation, and thus are sufficiently conspicuous tobe seen through our telescopes. The whole encloses an area on each sideof the canals within which large and important engineering works aresituated.
The canals which run along the bottom of the sea-beds are, of course, ata much lower level than the adjoining red area, and the canals on thelatter area are therefore at a higher level. Those canals which crossthe sea-beds cannot be carried by means of viaducts or embankments so asto place them upon the same level as the canals on the red areas,because that would defeat the purpose of irrigation, which is theirchief use. It is therefore necessary to lift the water from thelow-level canals and discharge it into those upon the higher ground.
This is accomplished by means of apparatus somewhat resembling anAmerican "grain-elevator," on a large scale; and it consists of a longseries of very large buckets, V-shaped in cross-section, attached toendless chain-bands, which, as they are carried round by the machinery,scoop up the water from the low-level canals and carry it up to therequisite height, from whence it is automatically discharged into thehigh-level canals. Of course it will be understood that the ends of thelatter canals are entirely closed by embankments so that no water canpass that way.
The buckets are an enormous size, and the electric machinery by whichthey are kept in motion is of the most ingenious description.
Besides this there is an immense amount of equally ingenious electricalmachinery for forcing the water along the canals.
Merna and Tellurio showed us all over the area, and carefully explainedthe construction and working of the various machines. I do not thinkM'Allister ever spent a more enjoyable time in his life, for he wentabout amongst the different machines examining them with the keenestinterest and manifestations of delight; and his note-book was inconstant requisition for making sketches and notes of what he saw.
We noticed that he was frequently smiling and chuckling to himself as ifhe were intensely pleased; and presently he came over to us, rubbing hishands together in high glee, and said to John, "Heh, mon, I reckon I seemy way to making a fortune when we return home, out of the ideas andwrinkles I'm getting here from the work of the Martian engineers!"
John laughed, and congratulated him heartily on his brilliant outlookfor the future, remarking that he did not appear to regret coming toMars.
"Indeed, I don't," M'Allister replied; "I'm thinking it will prove thevery best thing I've done in my life."
"Well, sir," said Merna, "I told you those machines would suit you as anengineer; are you satisfied now you have seen them?"
"More than satisfied," answered M'Allister; "they are the mostextraordinary and most ingenious machines I ever saw, and I wouldn'thave missed them for anything!"
At the sides of each high-level canal we saw a series of locks and weirsso constructed that vessels can pass on, in successive stages, from thehigh-level to the low-level canals, and _vice versa_.
These locks and weirs are all within the area enclosed by theembankments forming the carets, which accounts for the long andextensive space the latter cover, as the locks are necessarily aconsiderable distance apart from each other to allow for a length ofcanal to be traversed before the next lock is reached. They are,however, not in themselves sufficiently conspicuous to be separatelydiscerned from the earth by our telescopic observers.
Machinery for forcing the water along the canals is also provided atmost of the junctions everywhere on the planet. In this connection itmust be remembered that the water is carried by the canals from onehemisphere to the other, and, after passing the equator, must thereforemove in a direction contrary to that of ordinary gravitation.
Thus at one season of the year the water passes from the north polarregions down into the southern hemisphere, and at the opposite period ofthe year it is carried in the same way from the south polar regionsright into the northern hemisphere.
Gravitation being almost non-effective as regards the flow of water onMars, the movement would be extremely slow everywhere were it not forthe machinery, which adds to the speed of the flow. The average rate ofthe movement of the water in the canals is about fifty-one miles a day,and it takes about fifty-two days for the water to pass from aboutlatitude 72 deg. down to the equator, a distance of 2650 miles.
This rate of flow, as indicated by the darkening arising from the growthof vegetation which follows the flow of the water down the canals, hasbeen observed and noted many times at Flagstaff Observatory.
It was now perfectly clear to us why the "carets" are only seen in theparticular places in which they have been observed by Professor Lowelland his colleagues. They are, in fact, only needed in connection withwater-lifting apparatus, and locks and weirs, at the places wherehigh-level canals connect with those at a lower level!
We were all very pleased at finding the solution of a problem which hadbeen much discussed between us without arriving at any satisfactoryconclusion.
John then asked Tellurio if he would be good enough to explain to us howit was that our observers on the earth saw some of the Martian canalsdoubled at some periods of the year and single at other times; andsometimes one of the twin canals was seen alone, and at other times thesecond one only was visible.
"It is a very simple matter, sir," replied Tellurio. "You willunderstand that we do not wish to waste any of our water, and as it isquite unnecessary to use all our canals at the same time, we only usethose which are actually required. This arrangement also allows us tohave a much greater depth of water in the canals than would be the caseif they were all in use at once.
"Many of the canals are only required for irrigating seasonal crops; soas soon as the requisite amount of moisture has been acquired by thesoil the wa
ter is turned from that canal into another one, passingthrough an area where a later seasonal crop is to be grown. Thisarrangement, moreover, applies not only to our double canals, but alsoto very many of the series which you have regarded as single canals."
Thus the mysteries connected with Mars were being cleared up one afterthe other; and having regard to the very simple and natural explanationswe received, we could not help laughing as we talked the matter over andrecalled the immense amount of discussion and wrangling which hadoccurred amongst our scientific men in connection with these matters,and especially at the difficulty they seemed to experience in believingthat the canals could exist at all. Then there were those charges andtheories of overstrained eyes, diplopia, and defective focussing, to saynothing of other suggestions. Well, I will not say any more upon thispoint.
In continuation of our discussion of the canal question, I askedTellurio "Whether the canals and irrigation system had been the means ofreclaiming any large areas of land which had previously been deserts?"
"Oh yes, sir," he answered, "that has been the case in many parts ofour world; some very large areas indeed which were once deserts have nowbecome very fertile. Quite apart from such reclamations, however, ourcanals and irrigation systems have also effectually checked the spreadof desertism. If it had remained unchecked, probably by this time theentire surface of our planet would have become a desert."
I then explained that I asked the question because our observers hadseen and noted upon their charts several large areas which seemed tohave become fertile. Thus, along the eastern side of Thaumasia it hadbeen noted that, during a period of about twenty-three years, the greenarea had advanced at least 400 miles nearer to the place we called the"Solar Lake." On measuring this area on the map it appeared to me thatat least 200,000 square miles which had previously been desert hadbecome fertile.
Similar extensions of vegetation had also been charted in several otherplaces, for instance, on the east side of the large area known to us as"Syrtis Major." I had, however, been rather surprised not to have comeacross any comment by our scientists on the significance of this verylarge increase of fertile land, as, taken in connection with the greatcanal system, it seemed to me very significant and full of meaning.
Merna, continuing his remarks, then said that "Lately considerableextensions of their canal system had been carried out. New canals hadbeen dug, others altered or extended, and vast areas had beenconsiderably changed by replanting in some places and fallowing inothers. The result of all this work," he said, "would produce astriking alteration in the configuration of some of the dark areas. Suchchanges," he remarked, "were carried out very rapidly, so rapidly indeedthat it would probably be almost incredible to terrestrials; but it mustbe remembered that excavation, loading and removal of soil, as well asmost other operations, were accomplished by special machinery. He had nodoubt these changes would be noted by our observers, as Mars was sofavourably situated in regard to the earth at the present time. Besidesthis," he continued, "many of our canals have been dealt with, and someof them will disappear, either temporarily or permanently."
"Well, Merna," said John, "if that is the case our observers will soonmiss them; and I can imagine some of them gazing on your planet throughtheir telescopes and exclaiming, 'Lo! here is the symbol of the death ofMars. Where we used to see canals there is now only blank space; thecanals are disappearing, and the Martians must be rapidly decreasing innumbers and no longer able to maintain their vast canal system; orperhaps their water supply is diminishing so rapidly that it is becominginsufficient to keep the canals in working order; so ere long all lifeupon Mars must come to an end!'"
"If that should be so," said Merna, "they will be altogether wrong intheir surmises, for the disappearance of several of our canals will notindicate death but life. Some of those canals will only be temporarilyput out of use, but others, having served their purpose, will bediscontinued permanently. They are like our flowers that have doneblooming, which may be allowed to grow again next season, or the groundmay be fallowed and fresh flowers planted elsewhere; so the vanishedcanals may be succeeded by fresh ones where they are needed; and whenyour people see these new canals they will _know_ that they indicate thecontinued existence of vigorous and enterprising life upon Mars."
We then started upon our return home, and on the way I drew M'Allister'sattention to the smaller size of the sun as we saw it now as comparedwith the size it appeared to us when on the earth. I told him that Marswas then about 131,000,000 miles from the sun, so the sun's apparentdiameter was only about 22-1/4 minutes.
On the earth that day the sun's apparent diameter would be about 32minutes. So to the Martians the sun only appeared about two-thirds thesize it appeared to the people on the earth.
When, on 13th August this year, Mars was at its "perihelion," or nearestpoint to the sun, the latter was 129,500,000 miles distant, and wouldappear rather more than 22-1/2 minutes in diameter.
At the opposite point of its orbit, where it will be in "aphelion," orfarthest from the sun, the sun will only appear about 19 minutes indiameter.
I then explained that, although the sun is so distant, Mars receives avery much larger percentage of the total heat and light available thanwe do on the earth, because of the thinness and generally cloudlesscondition of the atmosphere. It is estimated that our atmosphere andclouds shut out nearly 50 per cent. of the light and heat which wouldotherwise reach us in the course of the year. On the other hand, their"blanketing" effect considerably lessens the amount of heat radiatedinto space; thus, by keeping in the heat we have received, compensatingto some extent for the original loss in quantity.
But, owing to its thin clear atmosphere, Mars receives nearly 99 percent. of the total amount of heat and light proceeding to it from thesun; so that, although the sun is more distant from the planet, thewarmth on Mars does not compare so unfavourably with the warmth on theearth as many have imagined it to do.
M'Allister replied that "He had expected to find it very cold indeedupon Mars in consequence of its distance from the sun, but was surprisedto find it so warm," and added, "what you have now told me, Professor,explains why this is so, and I can only say that at present I find theclimate a delightful one--pleasantly warm, yet bracing and invigorating.Even in the tropical regions, although it is hot, it is not theoppressive and enervating heat that I have experienced in the tropics onour own world."
He then remarked that "He knew the planets all moved through space andhad read that some of the stars did too, and he would like to knowwhether our sun had any motion in space?"
"Yes," I replied; "as the result of a long series of observations andcalculations it has been determined that the sun is moving through spaceand carrying with it all the planets in our system. Its rate of movementis not known with certainty, but it is estimated at about 1,000,000miles a day. Whether it is moving in a straight line or in a vast orbitaround some far distant sun is also an open question, and it may takecenturies to arrive at a definite result. This motion of our sun, rapidthough it is, is very slow compared with the motion of some of thestars. One that appears only a small star to us, but which is probablya sun enormously larger than ours, is moving through space at a ratewhich cannot be less than 200 miles a second; and unless that movementis direct across our line of sight its rate must be still more rapid.Yet it is so enormously distant that, in 500 years, it would only appearto have moved over a space of one degree on the sky! It is calculatedthat Arcturus moves still more rapidly.
"The movements of several other stars have been calculated; but thedistance of the stars is so enormously great that the majority appear tohave no movement at all, though probably not one of the heavenly bodiesis at rest.
"It is estimated that the light of the nearest star we know of takes atleast four years to reach the earth, yet light travels at the rate of186,000 miles a second. We know of others whose light takes centuries toreach us, and, with regard to most of the stars, the light we seeprobably left them thousands of
years ago.
"It is only when a star is so near to us that the earth's revolution inits orbit is sufficient to cause a change in the apparent position ofthe star which can be measured with our instruments that any calculationcan be made to determine its distance from us. In nearly all cases wherethe distance has been calculated, the change in position is so minuteand difficult to measure accurately, that the results obtained can onlybe regarded as very rough approximations to the real distances.
"The universe is infinite in extent, and the human mind is quite unableto conceive what is really implied in the distances of the planetsbelonging to our own solar system; yet they are as nothing whencompared with the distances of the fixed stars, either from the earth orfrom each other. We equally fail to realise the immense numbers of thestars. The camera, it is estimated, shows at least one hundred millionsin the heavens; and our great telescopes can penetrate throughinconceivable distances of space and render visible millions which thesmaller instruments fail to reveal. Every increase of instrumentalpower, however, carries us still farther, and reveals more and morestars in deeper depths of the illimitable abysses of space.
"In these matters there is no finality, for though with telescopic aid:
'World after world, sun after sun, star after star are past, Yet systems round in myriads rise more glorious than the last: The wondrous universe of God still limitless is found, For endless are its distances, and none its depths can sound!'"
