Unfortunately there is little chance that terrestrial observers will ever be able to watch the progress of great waves athwart the oceans of Mars, and still less that any disturbance of the frame of Venus should become discernible to us by its effects. We can scarce even be assured that there are lands and seas on Venus, so far as direct observation is concerned, so unfavourably is she always placed for observation; and though we see Mars under much more favourable conditions, his seas are too small and would seem to be too shallow (compared with our own) for great waves to traverse them such as could be discerned from the earth.
Yet it is well to remember the possibility that changes may at times take place in the nearer planets—the terrestrial planets, as they are commonly called, Mars, Venus, and Mercury—such as telescopic observation under favourable conditions might detect. Telescopists have, indeed, described apparent changes, lasting only for a short time, in the appearance of one of these planets, Mars, which may fairly be attributed to disturbances affecting its surface in no greater degree than the great Peruvian earthquakes have affected for a time the surface of our earth. For instance, the American astronomer Mitchel says that on the night of July 12, 1845, bright polar snows of Mars exhibited an appearance never noticed at any preceding or succeeding observation. In the very centre of the white surface appeared a dark spot, which retained its position during several hours: on the following evening not a trace of the spot could be seen. Again the same observer says that on the evening of August 30, 1845, he observed for the first time a small bright spot, nearly or quite round, projecting out of the lower side of the polar spot. “In the early part of the evening,” he says, “the small bright spot seemed to be partly buried in the large one. After the lapse of an hour or more my attention was again directed to the planet, when I was astonished to find a manifest change in the position of the small bright spot. It had apparently separated from the large spot, and the edges alone of the two were now in contact, whereas when first seen they overlapped by an amount quite equal to one-third of the diameter of the small one. This, however, was merely an optical phenomenon, for on the next evening the spots went through the same apparent changes as the planet went through the corresponding part of its rotation. But it showed the spots to be real ice masses. The strange part of the story is that in the course of a few days the smaller spot, which must have been a mass of snow and ice as large as Novaia Zemlia, gradually disappeared. Probably some great shock had separated an enormous field of ice from the polar snows, and it had eventually been broken up and its fragments carried away from the Arctic regions by currents in the Martian oceans. It appears to me that the study of our own earth, and of the changes and occasional convulsions which affect its surface, gives to the observation of such phenomena as I have just described a new interest. Or rather, perhaps, it is not too much to say that the telescopic observations of the planets derive their only real interest from such considerations.
I may note in conclusion, that while on the one hand we cannot doubt that the earth is slowly parting with its internal heat, and thus losing century by century a portion of its Vulcanian energy, such phenomena as the Peruvian earthquakes show that the loss of energy is taking place so slowly that the diminution during many ages is almost imperceptible. As I have elsewhere remarked, “When we see that while mountain ranges were being upheaved or valleys depressed to their present position, race after race and type after type lived out on the earth the long lives which belong to races and to types, we recognize the great work which the earth’s subterranean forces are still engaged upon. Even now continents are being slowly depressed or upheaved, even now mountain ranges are being raised to a different level, table-lands are being formed, great valleys are being gradually scooped out; old shore-lines shift their place, old soundings vary; the sea advances in one place and retires in another; on every side nature’s plastic hand is still at work, modelling and remodelling the earth, and making it constantly a fit abode for those who dwell upon it.”
STRANGE SEA CREATURES.
“We ought to make up our minds to dismiss as idle prejudices, or, at least, suspend as premature, any preconceived notion of what might, or what ought to, be the order of nature, and content ourselves with observing, as a plain matter of fact, what is.”—Sir J. Herschel, “Prelim. Disc.” page 79.
The fancies of men have peopled three of the four so-called elements, earth, air, water, and fire, with strange forms of life, and have even found in the salamander an inhabitant for the fourth. On land the centaur and the unicorn, in the air the dragon and the roc, in the water tritons and mermaids, may be named as instances among many of the fabulous creatures which have been not only imagined but believed in by men of old times. Although it may be doubted whether men have ever invented any absolutely imaginary forms of life, yet the possibility of combining known forms into imaginary, and even impossible, forms, must be admitted as an important element in any inquiry into the origin of ideas respecting such creatures as I have named. One need only look through an illuminated manuscript of the Middle Ages to recognize the readiness with which imaginary creatures can be formed by combining, or by exaggerating, the characteristics of known animals. Probably the combined knowledge and genius of all the greatest zoologists of our time would not suffice for the invention of an entirely new form of animal which yet should be zoologically possible; but to combine the qualities of several existent animals in a single one, or to conceive an animal with some peculiarity abnormally developed, is within the capacity of persons very little acquainted with zoology, nay, is perhaps far easier to such persons than it would be to an Owen, a Huxley, or a Darwin. In nearly every case, however, the purely imaginary being is to be recognized by the utter impossibility of its actual existence. If it be a winged man, arms and wings are both provided, but the pectoral muscles are left unchanged. A winged horse, in like manner, is provided with wings, without any means of working them. A centaur, as in the noble sculptures of Phidias, has the upper part of the trunk of a man superadded, not to the hind quarters of a horse or other quadruped, but to the entire trunk of such an animal, so that the abdomen of the human figure lies between the upper half of the human trunk and the corresponding part of the horse’s trunk, an arrangement anatomically preposterous. Without saying that every fabulous animal which was anatomically and zoologically possible, had a real antitype, exaggerated though the fabulous form may have been, we must yet admit that errors so gross marked the conception of all the really imaginary animals of antiquity, that any fabulous animal found to accord fairly well with zoological possibilities may be regarded, with extreme probability, as simply the exaggerated presentation of some really existent animal. The inventors of centaurs, winged and man-faced bulls, many-headed dogs, harpies, and so forth, were utterly unable to invent a possible new animal, save by the merest chance, the probability of which was so small that it may fairly be disregarded.
This view of the so-called fabulous animals of antiquity has been confirmed by the results of modern zoological research. The merman, zoologically possible (not in all details, of course, but generally), has found its antitype in the dugong and the manatee; the roc in the condor, or perhaps in those extinct species whose bones attest their monstrous proportions; the unicorn in the rhinoceros; even the dragon in the pterodactyl of the green-sand; while the centaur, the minotaur, the winged horse, and so forth, have become recognized as purely imaginary creatures, which had their origin simply in the fanciful combination of known forms, no existent creatures having even suggested these monstrosities.
It is not to be wondered at that the sea should have been more prolific in monstrosities and in forms whose real nature has been misunderstood. Land animals cannot long escape close observation. Even the most powerful and ferocious beasts must succumb in the long run to man, and in former ages, when the struggle was still undecided between some race of animals and savage man, individual specimens of the race must often have been killed, and the true appearance of the animal determined. Powerful winged animals might for a longer time remain comparatively mysterious creatures even to those whom they attacked, or whose flocks they ravaged. A mighty bird, or a pterodactylian creature (a late survivor of a race then fast dying out), might swoop down on his prey and disappear with it too swiftly to be made the subject of close scrutiny, still less of exact scientific observation. Yet the general characteristics even of such creatures would before long be known. From time to time the strange winged monster would be seen hovering over the places where his prey was to be found. Occasionally it would be possible to pierce one of the race with an arrow or a javelin; and thus, even in those remote periods when the savage progenitors of the present races of man had to carry on a difficult contest with animals now extinct or greatly reduced in power, it would become possible to determine accurately the nature of the winged enemy. But with sea creatures, monstrous, or otherwise, the case would be very different. To this day we remain ignorant of much that is hidden beneath the waves of the “hollow-sounding and mysterious main.” Of far the greater number of sea creatures, it may truly be said that we never see any specimens except by accident, and never obtain the body of any except by very rare accident. Those creatures of the deep sea which we are best acquainted with, are either those which are at once very numerous and very useful as food or in some other way, or else those which are very rapacious and thus expose themselves, by their attacks on men, to counter-attack and capture or destruction. In remote times, when men were less able to traverse the wide seas, when, on the one hand, attacks from great sea creatures were more apt to be successful, while, on the other, counter-attack was much more dangerous, still less would be known about the monsters of the deep. Seen only for a few moments as he seized his prey, and then sinking back into the depths, a sea monster would probably remain a mystery even to those who had witnessed his attack, while their imperfect account of what they had seen would be modified at each repetition of the story, until there would remain little by which the creature could be identified, even if at some subsequent period its true nature were recognized. We can readily understand, then, that among the fabulous creatures of antiquity, even of those which represented actually existent races incorrectly described, the most remarkable, and those zoologically the least intelligible, would be the monsters of the deep sea. We can also understand that even the accounts which originally corresponded best with the truth would have undergone modifications much more noteworthy than those affecting descriptions of land animals or winged creatures—simply because there would be small chance of any errors thus introduced being corrected by the study of freshly discovered specimens.