by Mark Wicks
CHAPTER XI
THE GREAT MARTIAN CONTROVERSY (_continued_)
"As the result of very long continued and systematic observation of thelines on Mars, together with carefully plotting them down on a globe, itwas found that every line was continuous, uniform in width, and wentstraight from one definite point to another, not one breaking off inopen space. Moreover, on being tested, nearly all were found to be arcsof great circles, and therefore the shortest possible lines which couldconnect any two points on a sphere. This fact strongly supports the ideathat they are not natural but artificial formations. For a long time thelines were only seen on the red, or lighter, parts of the planet, but in1892 an expedition was sent from Harvard Observatory to Arequipa, inPeru, for the purpose of observing the planet under very favourableconditions, and this resulted in important discoveries. Professor W.H.Pickering, who accompanied the expedition, was fortunate enough toobserve that the canal lines extended over the dark or blue-greenportions of the disc; and later observations have proved that this isthe case all over the planet, and the lines are visible from pole topole.
"These observations also led Professor Pickering to the importantconclusion that all the dark areas were covered with vegetation, andthat the bright or red areas were deserts, the colour of the latterbeing exactly that of our deserts when viewed from a great distance.Herschel's idea had been that the red areas were land covered withvegetation of a red colour, and that the dark areas were seas.
"It was, however, now quite clear that permanent lines in such numbersand length could not exist in seas; and other observations havedemonstrated that, instead of appearing smooth and uniform as waterwould, these areas are full of detail and variations, and that they passthrough all the changes of colour, according to seasons, that landcovered with vegetation does upon our earth. In the winter time, whenthe land is fallow, it appears brown or chocolate colour; in the spring,the time of early vegetation, it becomes a pale blue-green tint; as theseason advances the blue-green becomes darker; whilst in the autumn ittends to a light brown, and at length changes into chocolate colour inthe winter. This has been carefully noted time after time when theplanet has been in a position to be observed; and the same sequence ofchange--which can only be associated with vegetation--has alwaysoccurred.
"It may, therefore, now be accepted as a proved fact that the dark areasare land upon which vegetation grows, ripens, and dies away according tothe seasons of the Martian year.
"Professor Pickering also made another discovery, viz. a large number ofisolated, round, darkish spots, most of which occurred where canal linesjoined or crossed each other. Some of these had been seen much earlierby other observers, but Professor Pickering was the first to see them inlarge numbers and call attention to them. He termed them 'lakes,' butlater discoveries from continued observation showed that they were notwater, and they were then given the name of 'oases.' Some are seventy oreighty miles in diameter, and nearly two hundred are now marked on themaps. They mostly occur in certain definite positions--in the pointwhere single canals join or cross each other, or, in the case of doublecanals, between the two lines. It has been noted that they undergo thesame seasonal changes as the dark areas do, but only as regards theouter portion of the circle, which gradually fades away in the latterpart of the Martian year; whilst the central portion becomes fainter butdoes not disappear.
"Of course it was at once declared that these oases were illusions whichwould naturally be seen where two lines crossed each other and wereviewed from a great distance. But they only occur in some cases at suchcrossings, and there are many junctions without any oases. Moreover,they are also seen between the double canals where there are nojunctions nor anything which could give rise to illusion.
"At Flagstaff Observatory it was also noted that the canal linesthemselves underwent seasonal changes. Those viewed during the winterseason were always so faint as to be scarcely discernible, but at theperiod when vegetation would naturally begin to grow they became moreeasily visible, and still more distinct as the season advanced.
"Then Professor Lowell announced his great conception, which has givenrise to so much controversy, and has also been much misunderstood andmisrepresented.
"Briefly, his conclusions were as follows:--'Science teaches that asmall planet will become cool and develop life much sooner than a largeone. Similarly a small iron casting will become cool in a few days,whilst a large one will be many weeks or even months in cooling. A smallplanet will also develop more rapidly, and reach its final stage when itwill be incapable of supporting life, very long before a larger planetlike our earth will have reached that stage. Applying this to Mars, amuch smaller planet than our earth, it is scientifically reasoned thatMars has passed through nearly all its stages and is approaching itslast. It has lost much of its atmosphere, all its large bodies of water,such as oceans or seas, and, as regards the land, that has becomelevelled by erosion, and about five-eighths of the whole area has becomedesert.
"'Science also shows that in such circumstances rain would cease to fallover the larger part of the planet, but the water vapour in the airwould be carried by natural circulatory currents of air to the polarregions, and there deposited in the form of snow or hoarfrost, thusforming a large snow-cap at the north pole in one season of the year,and a still larger snow-cap at the south pole in the opposite portion ofthe year.
"'These snow-caps would begin to melt in the spring as soon as the tiltof the planet brought the pole to the position where the sun would takeeffect, and would continue during the early summer. As there is nopermanent glaciation on a planet which has lost its water, the snow-capwould melt to a very large extent, and the resultant water must gosomewhere.
"'The inhabitants of the planet could not exist without water, andtheir land would become entirely desert unless supplied with moisture.It will, therefore, be seen that the only thing possible, as a means ofself-preservation, would be for them to make channels to carry the waterin the most economical way from the poles to the parts where it wasneeded. Unless they found a means of doing this death stared them in theface. What greater incentive could there be!'
"This is what Professor Lowell is convinced has actually beenaccomplished upon Mars, with the result that there is a network ofcanals all over the planet by which water is conveyed from each pole andcarried across from one hemisphere into the other. The lines seen showwhere the canals are, but not the canals themselves, because they aretoo narrow to be seen. The lines really are broad bands of vegetationirrigated by the canals which run through them, hence the seasonalchanges which have been noted in their colour.
"All this seems very reasonable, deduced as it is from scientific factand from the many different things which have actually been seen andconfirmed by many thousands of observations, but it has met with themost bitter opposition on the part of many astronomers, bothprofessional and amateur. Theory after theory has been brought forwardwith the object of disproving the existence of the canal lines; some ofthese, such as eye-strain, diplopia, bad focussing, illusion, andimagination, have already been mentioned.
"Proofs of the reality of the lines having become too strong for most ofthe objectors, they then turned their endeavours to the overthrowing ofthe theory that the lines were canals, suggesting that they were all ofnatural origin.
"Amongst these suggestions it was stated they were edges of shadings,natural growths of long lines of trees and vegetation, cracks in thesurface of the planet or foldings caused by contraction, trap-dykes,&c., but not one of these suggestions will bear investigation. I havealready pointed out the impossibility of shadings having straight edgesfor thousands of miles in so many hundreds of cases. It is equallyimpossible to imagine natural growths of trees and vegetation in bandsof uniform width and thousands of miles long, and nearly all formingarcs of great circles.
"They cannot be cracks, for they are of uniform width throughout theirlength, and always run direct from one definite point to another, nomatter how distant apart they may be.
"Cracks, such as we see on the moon, though sometimes straight, areusually wide near the centre of disturbance which caused them, andnarrow off to a fine point, and often end anywhere out in open space;moreover, they are usually very irregular in width, and take a zig-zagcourse instead of a straight one. This, as I have said, is not the casewith a single canal line on Mars. If they were cracks, some at leastwould be irregular and end in open space. The same remarks apply in thecase of foldings or ridges.
"The oases, once declared to be illusions, were then said to be largeopenings in the soil at the junctions of the cracks; or they might becraters, and so on. But this does not account for the appearance of theoases between twin canals, or the systematic manner in which the canalseffect a junction with the oases. Again, therefore, the theory fails tofit the known circumstances of the case.
"Dr. A.R. Wallace rather favours the idea of natural cracks or faults inthe surface of the planet; and suggests that the outer crust of Mars maybe a crystalline or similar formation which would lend itself to theproduction of numerous cracks in the surface. He points to a few cracksand faults in the earth's surface, all of small size, as confirming thisidea; but the cases he adduces only seem to prove that there is on ourearth absolutely no natural formation which can in any way properly becompared with the lines seen on Mars. Moreover, there seems to me noground whatever, beyond the needs of the theory, for supposing that thecrust of Mars is of a crystalline nature, or such as would predispose tothe formation of cracks. On the contrary, all the evidence is againstit--the existence of vegetation in some parts, the general appearance ofthe red portion, and the large clouds of sand which have been observed,all being indicative of a sandy formation, in the red portion at least.
"The theory also fails to take into consideration the most importantpoint of all, viz. that every canal runs direct from one definite pointto another, perhaps over two thousand miles distant. In very many casesnumerous lines connect with one small area, or even with one point. TheLucus Ascraeus has no less than seventeen of these canals connecting withit, and appears to be a kind of Martian Clapham Junction.
"The deserts on Mars serve the same purpose as our seas, as lines ofcommunication may be established anywhere across them. A map of Mars,showing the canals converging towards some one part, bears a greatresemblance to our maps showing the courses taken by vessels fromdifferent parts all converging upon one seaport.
"Much has also been said about the widths of the canals as renderingthem impossible of construction, so let us consider how wide they are.
"The lines seen vary from two or three miles up to nearly thirty milesin width; but there are only one or two of the latter, and the majorityare five to ten miles wide. Notwithstanding Professor Lowell's repeatedstatements that they represent bands of vegetation, these widths areoften referred to as the widths of his canals. I have frequently seenthem described as 'fifty miles,' a 'hundred miles,' and even as'hundreds of miles' wide. These exaggerations usually appear innewspapers and journals, and evidently arise from insufficient knowledgeon the part of the writers.
"Owing to the small gravitation upon Mars, the work of digging canalswould be extremely easy upon that planet (even assuming the Martians tobe without machinery) as compared with the same work on our earth; butthere is neither necessity nor reason for the construction of suchenormously wide canals as those mentioned. Moreover, it seems to me thatvery wide canals would defeat the object for which they wereconstructed; and Professor Lowell does not regard the widest lines asbeing canals. They may be remains of natural channels or arms of theseas, as they do not run so straight as the canal lines proper.
"Our people," I remarked, "have argued both against the possibility ofconstructing such canals and of forcing water along them, because, asthey say, none of our engineers would be able to accomplish such work. Icertainly have more confidence in the skill and capabilities of ourengineers, and doubt not that if they were required to solve a similarproblem they would overcome all difficulties and carry out the worksuccessfully."
"I'm with you there, mon!" exclaimed M'Allister.
"I may remind you," I proceeded, "that when steam navigation was firstmooted, it was confidently asserted that no steamship would ever succeedin crossing the Atlantic Ocean, and I can remember when it was learnedlydemonstrated that it would be quite impossible to construct a canalacross the Isthmus of Suez! How small the prophets must have felt whenthe work was accomplished!
"I am afraid it is usual to take a very limited view of all suchmatters, and we judge of them entirely from what we know ourselves,never looking ahead, as it is considered unscientific to go beyond ourown knowledge. Because something may be quite impossible to us, it doesnot follow that it is impossible to more advanced people.
"Think how many great scientific facts which are quite commonplace atthe present time were unknown and undreamed of even so recently as ourgrandfathers' time! Who then can forecast what may be possible fivehundred years, or even a century hence; and who will be bold enough tofix a limit to the possibilities of science! I freely admit I am anoptimist in these matters."
"I think, Professor," said John, "that your view is really the morescientific of the two. While it may not be possible accurately toforecast all the facts, intelligent anticipations may logically beformed from a survey of our own past history."
Proceeding, I then remarked, that "Another discovery made at FlagstaffObservatory was that at the ends of certain canals, where they joinedthe dark areas, were small V-shaped dark markings which Professor Lowellhas termed carets. From their occurrence in these positions only, andfrom his observations of the peculiar and extremely systematic manner inwhich the canals, especially the double ones, run into the carets, hehas concluded that they must serve some special and important purpose.
"We have been told upon high authority that the carets are illusions,and could not possibly be seen, as the planet is so distant from us. Butthe fact remains that they have frequently been seen and drawn; theyalways appear the same, and are never seen except in connection withcanals which join dark areas. These dark areas, I may say, are believedto be the beds of ancient seas, from which the water has long sincedeparted.
"In connection with all these disputed lines and markings it has oftenbeen urged that though they are seen through comparatively smalltelescopes they are not seen when a very large instrument is used; andit has also been said that observers, knowing what they wished to see,simply imagined they did see it. We have, however, abundant proof thatboth these arguments are unreliable and incorrect.
"It is a well-known fact that when a faint object has been once seenthrough a telescope, others are able to see it through a smallerinstrument. This was the case with the satellites of Mars, which havebeen seen with much smaller instruments than that used to discover them.
"The fact that such objects are really seen is proved by the observermarking them on his drawing in their correct position, although they mayhave moved from the point at which they were originally seen.
"I will give you an illustration of the ease with which it is possibleto overlook something that should be clearly visible to you, yet it isnot seen by you until your attention is called to it by some one else.Almost every one has had some such experience:--
"You may have on the front of your coat a small stain, or grease-spot,in a position where you could plainly see it, yet might wear the coatfor days or even weeks in complete unconsciousness of the existence ofthe stain until some one pointed it out to you. After that you cannotlook at the coat without seeing the stain, and it becomes sopersistently obtrusive that you are compelled to have it removed. Thereis, however, no imagination about your seeing the mark."
John here said to me: "Professor, I noticed you said that many who donot believe in the actuality of the lines and markings on Marsfrequently refer to the fact that, while they are stated to be seenthrough small telescopes, they are quite invisible through a very largeinstrument, and they regard this as proving that the
lines or markingsdo not exist. Is there not something in this argument?"
"Well, John," I replied, "the argument sounds not only plausible, butreasonable, and inexperienced persons might use the argument, believingit to be a sound and good one. I must, however, confess that I havebeen surprised to see this argument used by persons who must surely knowthat there is no weight in it at all.
"It is well known to all practical observers, and indeed to all who havestudied optical matters, that, for several reasons, very largetelescopes are quite unsuited for the observation of fine planetarydetail.
"The real advantage of these enormous instruments lies in their great'light-grasp,' which enables observers to see very faint points oflight, such as small satellites of planets, faint stars, double stars,distant comets, or nebulae, which could not be seen with a smallerinstrument necessarily having less 'light grasp.' Yet this very excessof light, which is the great advantage of a large instrument, is one ofthe things that spoils the definition of faint planetary details; itdrowns them all out, or 'breaks them up.'
"Again, these large instruments are much more liable than smaller onesto what is termed 'chromatic' and 'spherical' aberration; and this alsois detrimental to definition. No very large refractor is entirely freefrom these defects.
"Another objection is that, in using such large and long-focussedinstruments, a much higher power must necessarily be employed than inthe case of smaller instruments. This high power magnifies all thelittle movements and disturbances in our atmosphere to exactly the sameextent as it magnifies the object looked at, with the result that thesedisturbances blur out all fine detail. The canal lines on Mars couldnever be seen in such circumstances. If the object were looked atthrough a smaller instrument, with lower power, it might be fairly wellseen, for the atmospheric disturbances would not be magnified to suchan extent as to spoil definition.
"There are very few nights in the year when these immense instrumentscan be used to advantage on the planets, whilst a smaller instrumentmight define well three or four nights out of every six. It is on recordthat the user of Lord Rosse's great reflector stated that there wereonly about three nights in the year when its best definition could beobtained; and its use has produced very meagre results, compared withwhat had been anticipated.
"It is also almost universally recognised that in using these greatinstruments, whether for photography or for the visual observation offine detail, it is absolutely necessary to stop down the aperture to avery large extent, by reducing it to about 12 inches in diameter or evenless. The big telescope is thus really converted into a small one oflong focus.
"There is, in addition, the acknowledged fact that nearly everydiscovery of new detail on planets has been made with a comparativelysmall telescope, although the same objects may have been under constantobservation for years with big telescopes. The new detail was nevernoticed until after it had been seen with a smaller instrument, andperhaps only then when atmospheric conditions were unusually good.
"As an instance, I may mention that the faint 'crape ring' of Saturn wasseen by Dawes when using an 8-inch aperture to his telescope; yet it hadnever been discovered with the large instruments, although the planet isone that is under constant observation when in a position to be seen.
"I could give innumerable instances of similar cases, but enough hasbeen said to show that because some object cannot be seen in a verylarge telescope, it is no proof at all that the object does not exist.
* * * * *
"Amid the chaos of varied, and often self-contradictory, theoriesrespecting Mars--some abandoned by their own authors; others in whichfacts and conditions had to be assumed for which there was not only noevidence, but actual disproof by many recorded observations--ProfessorLowell's conceptions stand out clearly and boldly.
"They are all founded on the results of prolonged and systematic work inthe observation of the planet, not only by himself but by numerouscolleagues--work in which many of his critics have had little or noexperience under favourable conditions. His conceptions fit in withobserved facts with all the accuracy of the pieces in a child's picturepuzzle; whilst his logical deductions are supported and enhanced by hiswide knowledge of physical science and planetology.
"Yet, as I have both heard and read, his views and discoveries have beendescribed as 'sensational,' 'fanciful,' 'fairy tales,' and by otherterms which I would rather not quote.
"Underlying some of these objections there seems to be an idea that somereason _must_ be found for opposing anything and everything which wouldtend to indicate the possibility of intelligent life existing upon anyother planet than the earth; although it is difficult to understand whysuch a possibility should be so abhorrent. It is a view that does notcommend itself to me, but I need not say more on that point.
"Nicola Tesla, the great electrician, is, however, convinced of theexistence of life upon Mars, and he has expressed in very emphatic termshis opinion of the opposite view, which, however, I refrain fromquoting. He says that Mars must have passed through all terrestrialchanges and conditions, and that the whole arrangement of the canals, asdepicted by Professor Lowell, would seem to be artificially designed. Hethen goes on to state that he has discovered electrical disturbances onthe earth which must have come from Mars and no other planet.
"In the treatment he has received from some of his smaller critics(whose vehemence is usually in inverse proportion to their knowledge ofhis work and writings) Professor Lowell has had an experience similar tothat of many other observers who have done good work.
"If an observer be blessed with the happy combination of good eyesight,a good instrument, and favourable atmospheric conditions, and publisheswritings and drawings showing that he has seen something which has notpreviously been observed, he at once becomes a target for captiouscritics who seem to be under the impression that all astronomicalknowledge begins and ends with themselves, and that anything they cannotsee does not exist. It matters not that the observer attacked may havegiven months to particular observations where his critics have onlyspent a few hours: he is told that his drawings are incorrect and do notrepresent the planet; that they may be works of art, but do notrepresent facts; that he possesses a very vivid imagination, and so on.This procedure may be persisted in until at last the victim either turnsand rends his critics or ceases to publish his drawings or records, tothe great loss of many others who take an intelligent interest in hiswork.
"Professor Lowell's telescope is over 32 feet in focal length, and hasan object glass of excellent quality 24 inches in diameter, the work ofthe celebrated Alvan Clark. Thus, whilst not one of the giants, it isnot exactly what would be termed a small instrument, and few indeed ofthe critics have anything approaching it in capacity, while none enjoysthe advantage of such ideal conditions in the situation of hisobservatory.
"I was therefore much amused in reading an effusion by one critic who,in discussing the question of the canal lines, remarked that he couldnot accept 'these one-man discoveries,' oblivious of the fact that theyare the discoveries of many observers. He then very naively gives theilluminating information that his astronomical experience is confined tothe 'observation' of the _moon_ for about six months, by the aid of a1-1/4-_inch hand-telescope_! Surely, when confronted with a critic ofsuch vast experience and so wonderfully equipped, Professor Lowell mustretire discomfited from the field!"
At the conclusion of my remarks both John and M'Allister expressed theirthanks, saying that "Now they were informed as to the points on whichour scientists were not agreed, they would look forward with stillgreater interest to our arrival at our destination, for they were asanxious as I was to solve the mysteries of the red planet."
