by Anthology
"Quite right, Professor, so you did," said M'Allister; "but I did not fully understand the reason of your instructions."
"But," interrupted John, "are we not going rather out of our way?"
"Yes, that is so, John," I replied, "but a few thousand miles more or less will make very little difference to us at the rate we shall travel, especially if you allow for the fact that the earth and moon are both moving nearly in the direction we wish to go. Besides, I hope to approach sufficiently near the moon to enable us to add a little more power to our store, so it will not all be lost time; and we can also use the moon to give us a fresh start. But for the fact that it would be best for us to reach the moon before it has waned to any large extent we might have delayed our start for many days, and, whilst considerably shortening our journey, still arrived at Mars on the date we have fixed."
Our chronometer was housed in a substantial non-magnetic cubicle, with a very thick glass window, in order to protect it from the magnetism and electricity which pervaded our vessel. On looking at the chronometer I found the time was nearly eleven o'clock. We had, therefore, been nearly two hours on our journey and had travelled some three hundred miles, mostly in an upward direction from the earth; so if there were any of the earth's atmosphere around our vessel it must be of the most extreme tenuity, and we might safely increase our speed.
I accordingly gave M'Allister the order to switch on the power gradually, up to our full speed, and it was not long before we were rushing through space at the rate of over eighty-three thousand miles an hour. At this rate, as I told them, we might expect to reach the moon in a little over sixteen hours, allowing for loss in slackening down at the latter part of the journey.
"It so happens," I said, "that the moon's present distance from the earth is rather less than 226,000 miles, being its nearest approach to the earth during this month."
John at once asked, "How it happened that, if the moon were only this comparatively short distance away from us, I reckoned it would require over sixteen hours to reach it at the tremendous speed we were now moving"; and added, "I thought we should be there in about three hours."
"Ah, John," I replied, "you have forgotten that the earth is rushing along and carrying the moon with it nearly as fast as we are travelling, and you are reckoning as though they were standing still all the time. As a matter of fact we are only gaining on the moon by a little over fifteen thousand miles an hour, and we must allow for slackening speed long before we reach the moon, so we cannot expect to cover the distance in less than sixteen hours. You will see that if we did not travel faster than the moon is moving away from us we should never catch it up at all!"
"That explains it all, Professor," said John, "and I must confess I felt rather puzzled at the length of time required to reach the moon, so was altogether out in my calculations."
After we had been proceeding at this rate for nearly two hours, M'Allister came hurrying into our compartment in a state of great excitement.
"Professor," he exclaimed with a gasp, "something's gone wrong altogether, and I don't know what to do!"
"Gone wrong!" I repeated. "Why, what is the matter?"
"Mon," he answered, "everything is the matter! A while back we were rushing towards the moon, but just now when I looked ahead there wasn't any moon to be seen. I happened to go round to the other window and look back and, my word! if there wasn't the moon right behind us! We have been travelling so very fast that we must have run past it without knowing we had done so."
"Oh, we could not possibly have done that!" I exclaimed.
"But there's more to come, Professor," continued M'Allister. "When I last saw the moon it was nearly full and not so very much bigger than when we saw it at starting, but now this moon behind us is an enormous thing; yet it is only a new moon, or rather what folks call a new moon with the old moon in its arms!"
"Oh, now I understand," I replied. "It's all right, M'Allister, and you can make your mind quite easy. You were not able to see the moon when you first looked through the window because it was nearly in a direct line with your course, and therefore just hidden by the prow of the vessel. It's still ahead of us and still nearly full: if you had looked out of the conning tower or used the periscope you would have seen it."
"Heh, Professor," he interjected, "I know I couldn't see the moon if it was straight ahead of our course, but then what about that enormous new moon that's behind us? I saw that right enough."
"That enormous new moon, M'Allister, is only our own little world which we left a few hours ago," I replied.
He stared at me as though bewildered, and after pondering a while, exclaimed, "Losh, mon, you surely don't mean to say that our own little world changes about in the same way as the moon does—sometimes new and sometimes full?"
Here John interposed. "Yes, M'Allister, you can take it from me that it is just what our world does do. I think you are aware that, like the moon, our world simply reflects the light it receives from the sun, and does not shine by its own light. So one side is light and the other side is dark, according to its position in regard to the sun. From our present position we are only able to see a small portion of the lighted side, the remainder being dark except for the moonlight shining upon it, so it looks just like a large new moon. It really serves as a moon to our moon, but its phases follow each other in reverse order. Thus, when the moon is full, the earth's disc is all dark, and when the moon is in its first quarter the earth, as seen from there, would be in its third quarter, and so on through all its phases. Do you follow all that, M'Allister?"
"Well, mon," replied M'Allister, with a sly grin, "I've just heard you say it; but"—and here he turned to me—"is it all correct, Professor?"
"Yes, quite correct," I answered, greatly amused at his distrust of John's statements.
"M'Allister, you're like the Apostle Thomas," commented John, evidently a little nettled; "so you really doubted my word after all!"
"Heh, mon," he answered, "you're not the Professor, you know; and I thought maybe you were pulling my leg!"
"Well," laughed John, "perhaps you will get your leg pulled the next time I condescend to give you a lesson in astronomy!"
After this little spar between my two colleagues we proceeded to the machine-room, which John and I carefully inspected, to make sure that all was working properly; and having satisfied ourselves on this point, we gave M'Allister his instructions for the 'night'; though of course there was no night now.
Mounting the steps of the conning turret, we then had a look at the earth, from which we were so rapidly moving away. It appeared about fifteen degrees in angular diameter, showing that we had travelled some thirty thousand miles from it.
The full moon, as seen from the earth, appears just about half a degree in diameter—sometimes a little more, sometimes rather less; so the earth was apparently about thirty times the diameter the moon usually appears to us. It was only a thin crescent where lighted by the sun, but well might M'Allister describe it as "enormous," for it appeared still larger to him when he saw it some thirty minutes earlier and mistook it for the new moon.
When we came down again John, very thoughtfully, said to me, "Professor, you have had a very long, tiring day; and when we reach the moon, we shall probably stay up several hours to look at it, so you had better take as long a sleep as possible. There will be no need to break your rest, for I'm the younger, and will get about by six o'clock, and relieve M'Allister, who can go on all right up to then, as he has three hours less work to his credit than we have to-day. If your advice is needed, I will call you at once; but, no doubt, we shall do very well till we arrive within a few thousand miles of the moon. We will slacken speed very gradually from about two o'clock in the afternoon, so as not to approach the orb too rapidly."
I had, indeed, as he said, had a long, tiring day, having risen soon after four o'clock yesterday morning, and it was now nearly 2 "A.M." by terrestrial time; so, thanking him for his kind consideration, I bade them both
"good night," and gladly proceeded to bed, John following soon after.
He was as good as his word, and actually allowed me to sleep on until nearly half-past three in the "afternoon," when he roused me, and, having dressed, I snatched a hasty meal and then at once proceeded to the machine-room, where my first act was to look at the moon. There it was below us, but still slightly ahead of the Areonal; and its magnificence was so overpowering, that it almost seemed to take my breath away, although I was fairly well prepared for the sight. Many times when viewing it through the telescope I have almost lost myself in admiration of the sublime spectacle it presents; but what I had seen on those occasions could not be compared with the splendour of the view now before us.
Here, without any atmosphere to dim or otherwise mar the view, the brilliancy of the lighted portion of the disc was absolutely dazzling, whilst the extreme delicacy of its varied tints and the subtle nuances of colour, which we now saw to perfection, were most charming and delightful to any one endowed with artistic perceptions. We were only about four thousand miles from this beautiful orb, its angular diameter measuring about thirty degrees, or nearly sixty times its apparent diameter, as seen from the earth; thus it appeared to cover a very large circle on the sky.
John and M'Allister told me they had both been gazing upon the splendid scene for a very long time with astonishment and delight equal to my own; and the latter went on to say, "Professor, did you ever see such a sight in your life? I never did, and could never have imagined that anything could be so beautiful! Mon, it's worth many a journey like this to see such a bonnie thing!"
"You are quite right in saying that, M'Allister," I answered; "it is, indeed, a grand and marvellous sight! I can assure you that when I have been observing the moon in its full and glowing splendour, it has often seemed to me the most exquisitely beautiful object I have ever looked upon; yet now it appears far more beautiful than when seen through the telescope!"
Chapter IV
CLOSE TO THE MOON—I GIVE SOME INFORMATION ABOUT IT
We were now moving at a comparatively slow speed, yet the size of the moon's disc was very rapidly expanding as we approached nearer and nearer to it. In the course of a little over half-an-hour we were within ten miles of its surface, which now seemed to fill the whole space below us; and its rotundity was most impressive. The shadows of the mountains and other elevated portions near the terminator[4] were jet black, owing to the absence of an atmosphere; and, seen contrasted with the brilliant lighting of the parts exposed to the full glare of the sun, appeared almost like deep holes in the lunar surface.
John now remarked, "Professor, you are aware that I have only a rather vague general knowledge of astronomy, although I take an interest in the subject, and that I know still less about the dimensions and physical character of the moon and planets; so perhaps you will be good enough to give us a little detailed information respecting this beautiful orb. Most of it will be news to me, and probably it will all be fresh to M'Allister."
"Heh mon," the latter replied, "just put me among machinery and I'll tell you what's what, but I never learned anything about astronomy, so will not pretend to any knowledge of it, but now I should be very glad to hear what the Professor has to say about it."
"Well, friends," I replied, "it is not my wish to lecture you upon the subject, so I will merely just run over a few of the bare facts.
"To begin with—the moon is very much smaller than the earth, its diameter being only 2160 miles, while the earth's diameter is 7918 miles. Being a smaller globe its mass is much more loosely compacted than that of the earth, so, although it would take nearly fifty globes the same as the moon to make one globe as large as the earth, it would require nearly eighty such globes to make one as heavy as the earth.
"The moon's distance from the earth is generally given as being about 238,000 miles, but this is its mean distance. When farthest away from our world its distance is about 260,000 miles, but at its nearest it is less than 220,000 miles distant. This difference of course arises from the eccentricity of the moon's orbit, and it explains why we sometimes see the moon a trifle larger than it appears at other times. By this I mean that it really is seen larger, because it is closer to us. But you have no doubt often noticed that when the moon is near the horizon it seems to be very large indeed. This apparent increase of size is, however, an illusion, owing to our unconsciously comparing it with the apparent size of terrestrial objects.
"The surface of the moon shows evidence of very violent volcanic action having occurred in every part of it, and astronomers in the past were much puzzled to account for the excessive volcanic energy which was indicated by what they saw, as such a small globe as the moon would not, in the ordinary course of events, have ever possessed sufficient heat to have developed such violent action. A theory of later years has, however, provided a reasonable explanation. It is that the moon was at one time a part of the same mass as the earth, which became separated from it before the earth had quite cooled down and solidified into its present form, and was then gradually driven farther and farther away from the earth by natural forces. It was therefore originally as hot as the rest of the mass which formed the earth, but being formed into a smaller globe of much less gravity—only one-sixth of that of the earth—volcanic action of the same intensity as that on the earth would have a much more far-reaching effect. A force which on the earth would project volcanic lava and scoriæ a distance of three miles would, on the moon, project it a distance of eighteen miles. This accounts for the very high mountains we see on the moon, some of which are comparatively, for the size of the globe, much higher than those on the earth. It also accounts for the vast size of the lunar craters, ring-plains, and ring-mountains.
"These latter are formations quite unknown upon our earth, but on the moon they are numbered by hundreds of all sizes, from a few miles up to one hundred and fifty miles in diameter. They are large plains, roughly circular in shape, and surrounded by mountains; in a few cases the ring is in some parts a double range of mountains. Sometimes the plain (or 'floor,' as it is termed) is many thousands of feet below the general level of the lunar surface; in a few cases it is raised considerably above it, and in one or two instances, instead of being flat, the floor is convex. Some of the mountain rings are comparatively low, but in other cases the mountains are fifteen to twenty thousand feet in height, or even higher. Frequently a mountain rises near the centre of the floor, some rings containing more than one such mountain, whilst others have none at all.
[Illustration: Drawn by M. Wicks Plate II
IDEAL VIEW OF LUNAR SCENERY
As there is no atmosphere on the moon, the sky is a dense black, and the stars shine brilliantly in the daytime. The view is a typical one, showing numerous craters and cracks, and a small ring-mountain with terracing. Ring-mountains and plains vary from a few miles to 150 miles diameter, some mountains being nearly 20,000 feet in height.]
"There are numerous instances where one mountain ring has overlapped or cut into another, thus indicating that it was a later formation; and in many cases the mountains are 'terraced,'[5] as it is termed, either owing to a series of landslips or to the rise and fall of a sea of lava, which cooled as it sank down, thus forming terraces. Small craters abound all over the surface of the moon and on the floors of the rings; cracks in the lunar surface are also numerous.
"As regards the lunar mountains, it may truly be said that we have a fairly accurate knowledge of peaks and mountains which would either be too precipitous to be climbed, or quite inaccessible to us, if we could actually land upon the moon; and the whole visible surface has been more carefully and thoroughly mapped out and studied than is the case with many parts of our own earth.
"If the moon has any atmosphere it must be so very attenuated indeed that human beings could not possibly live in it at all; but nothing has yet been detected which would enable us to say positively that any atmosphere does exist there, although there have been some indications observed which
support the supposition that there may be an extremely thin air.
"Nor does it appear possible that there is any water upon its surface at the present; in fact, many astronomers are of opinion that the moon never did have any water upon it. Personally, from a study of many of the formations as seen through the telescope, it seems to me quite impossible that they could owe their existence in their present state to anything but the action of water. They present much the same appearance as formations on our own earth which we know have been fashioned by that means. There is no water upon the moon now, I think, though several large depressions are still called oceans, seas, lakes, or marshes, because at one time they were believed to be such. Probably in some of those places, if not in all, water existed millions of years ago; but ages since they must have lost it either by evaporation or by absorption into the soil.
"I will not say any more just now, but as we pass above the lunar surface I will point out a few of the natural features that may be of interest to you."
M'Allister here paid me the compliment of saying, "Well, Professor, I always thought astronomy was a very dry and difficult subject; but your remarks were really very interesting, and quite easy to understand. There is only one thing that seemed to me rather strange as coming from a scientific man, and I would like you to explain that."
"Certainly; if there is anything you do not quite understand, you have only to ask and I will try to clear the matter up," I answered. "What is it you wish to know?"
"Well," he answered, "I noticed that when you were speaking about the distance of the moon you always said it was about so far away. Why didn't you tell us the exact distance? I'm not a scientific man by any means, but if any one were to ask me the length of a connecting rod on one of my machines I should say '25 inches,' not 'about 25 inches,' for that would not do for a practical man!"