one hemisphere into the other. The lines seen show where the canals are, but not the canals themselves, because they are too narrow to be seen. The lines really are broad bands of vegetation irrigated by the canals which run through them, hence the seasonal changes which have been noted in their colour.
“All this seems very reasonable, deduced as it is from scientific fact and from the many different things which have actually been seen and confirmed by many thousands of observations, but it has met with the most bitter opposition on the part of many astronomers, both professional and amateur. Theory after theory has been brought forward with the object of disproving the existence of the canal lines; some of these, such as eye-strain, diplopia, bad focussing, illusion, and imagination, have already been mentioned.
“Proofs of the reality of the lines having become too strong for most of the objectors, they then turned their endeavours to the overthrowing of the theory that the lines were canals, suggesting that they were all of natural origin.
“Amongst these suggestions it was stated they were edges of shadings, natural growths of long lines of trees and vegetation, cracks in the surface of the planet or foldings caused by contraction, trap-dykes, &c., but not one of these suggestions will bear investigation. I have already pointed out the impossibility of shadings having straight edges for thousands of miles in so many hundreds of cases. It is equally impossible to imagine natural growths of trees and vegetation in bands of uniform width and thousands of miles long, and nearly all forming arcs of great circles.
“They cannot be cracks, for they are of uniform width throughout their length, and always run direct from one definite point to another, no matter how distant apart they may be.
“Cracks, such as we see on the moon, though sometimes straight, are usually wide near the centre of disturbance which caused them, and narrow 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-zag course instead of a straight one. This, as I have said, is not the case with a single canal line on Mars. If they were cracks, some at least would be irregular and end in open space. The same remarks apply in the case of foldings or ridges.
“The oases, once declared to be illusions, were then said to be large openings in the soil at the junctions of the cracks; or they might be craters, and so on. But this does not account for the appearance of the oases between twin canals, or the systematic manner in which the canals effect a junction with the oases. Again, therefore, the theory fails to fit the known circumstances of the case.
“Dr. A.R. Wallace rather favours the idea of natural cracks or faults in the surface of the planet; and suggests that the outer crust of Mars may be a crystalline or similar formation which would lend itself to the production of numerous cracks in the surface. He points to a few cracks and faults in the earth’s surface, all of small size, as confirming this idea; but the cases he adduces only seem to prove that there is on our earth absolutely no natural formation which can in any way properly be compared with the lines seen on Mars. Moreover, there seems to me no ground whatever, beyond the needs of the theory, for supposing that the crust of Mars is of a crystalline nature, or such as would predispose to the formation of cracks. On the contrary, all the evidence is against it—the existence of vegetation in some parts, the general appearance of the 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 important point of all, viz. that every canal runs direct from one definite point to another, perhaps over two thousand miles distant. In very many cases numerous lines connect with one small area, or even with one point. The Lucus Ascr?us has no less than seventeen of these canals connecting with it, and appears to be a kind of Martian Clapham Junction.
“The deserts on Mars serve the same purpose as our seas, as lines of communication may be established anywhere across them. A map of Mars, showing the canals converging towards some one part, bears a great resemblance to our maps showing the courses taken by vessels from different parts all converging upon one seaport.
“Much has also been said about the widths of the canals as rendering them impossible of construction, so let us consider how wide they are.
“The lines seen vary from two or three miles up to nearly thirty miles in width; but there are only one or two of the latter, and the majority are five to ten miles wide. Notwithstanding Professor Lowell’s repeated statements that they represent bands of vegetation, these widths are often referred to as the widths of his canals. I have frequently seen them described as ‘fifty miles,’ a ‘hundred miles,’ and even as ‘hundreds of miles’ wide. These exaggerations usually appear in newspapers and journals, and evidently arise from insufficient knowledge on the part of the writers.
“Owing to the small gravitation upon Mars, the work of digging canals would be extremely easy upon that planet (even assuming the Martians to be without machinery) as compared with the same work on our earth; but there is neither necessity nor reason for the construction of such enormously wide canals as those mentioned. Moreover, it seems to me that very wide canals would defeat the object for which they were constructed; and Professor Lowell does not regard the widest lines as being canals. They may be remains of natural channels or arms of the seas, as they do not run so straight as the canal lines proper.
“Our people,” I remarked, “have argued both against the possibility of constructing such canals and of forcing water along them, because, as they say, none of our engineers would be able to accomplish such work. I certainly have more confidence in the skill and capabilities of our engineers, and doubt not that if they were required to solve a similar problem they would overcome all difficulties and carry out the work successfully.”
“I’m with you there, mon!” exclaimed M’Allister.
“I may remind you,” I proceeded, “that when steam navigation was first mooted, it was confidently asserted that no steamship would ever succeed in crossing the Atlantic Ocean, and I can remember when it was learnedly demonstrated that it would be quite impossible to construct a canal across the Isthmus of Suez! How small the prophets must have felt when the work was accomplished!
“I am afraid it is usual to take a very limited view of all such matters, and we judge of them entirely from what we know ourselves, never looking ahead, as it is considered unscientific to go beyond our own knowledge. Because something may be quite impossible to us, it does not follow that it is impossible to more advanced people.
“Think how many great scientific facts which are quite commonplace at the present time were unknown and undreamed of even so recently as our grandfathers’ time! Who then can forecast what may be possible five hundred years, or even a century hence; and who will be bold enough to fix a limit to the possibilities of science! I freely admit I am an optimist in these matters.”
“I think, Professor,” said John, “that your view is really the more scientific of the two. While it may not be possible accurately to forecast all the facts, intelligent anticipations may logically be formed from a survey of our own past history.”
Proceeding, I then remarked, that “Another discovery made at Flagstaff Observatory was that at the ends of certain canals, where they joined the dark areas, were small V-shaped dark markings which Professor Lowell has termed carets. From their occurrence in these positions only, and from his observations of the peculiar and extremely systematic manner in which the canals, especially the double ones, run into the carets, he has 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. But the fact remains that they have frequently been seen and drawn; they always appear the same, and are never seen except in connection with canals which join dark areas. These dark areas, I may say, are believed to be the beds of ancient seas, from which the water has long since departed.
“In connection with all these disputed lines and markings it has often been urged that though they are seen through comparatively small telescopes they are not seen when a very large instrument is used; and it has also been said that observers, knowing what they wished to see, simply imagined they did see it. We have, however, abundant proof that both these arguments are unreliable and incorrect.
“It is a well-known fact that when a faint object has been once seen through a telescope, others are able to see it through a smaller instrument. This was the case with the satellites of Mars, which have been seen with much smaller instruments than that used to discover them.
“The fact that such objects are really seen is proved by the observer marking them on his drawing in their correct position, although they may have moved from the point at which they were originally seen.
“I will give you an illustration of the ease with which it is possible to overlook something that should be clearly visible to you, yet it is not seen by you until your attention is called to it by some one else. Almost every one
