"Yes, certainly I should," replied M'Allister.
"Now," I continued, "suppose that the other vessel, instead of being at rest, was moving away from you at the rate of six miles an hour; after you had steamed one hour it would still be six miles ahead of you, and it would take you exactly another hour to catch it up. So you would be just double the time reaching it when moving as compared with the time required to do so when it was at anchor. This is very similar to the cases of the satellites of Mars, and much the same thing happens in regard to Mars and the earth. If they are opposite to each other at a certain point, Mars will have taken much more than one revolution round its orbit before they will be opposite to each other again, because they are both moving in the same direction. Do you see it now?" I asked.
"Yes, Professor," he replied. "I know now, because you have cleared it all up. It's simple enough when one understands it."
Merna then asked me if I would like to see some of their astronomical instruments, and, on my replying that I should very much like to do so, he took us to an observatory where Corontus was at work.
I was at once struck by the small size of the telescopes; and, on inquiring about them, Corontus told me that very large instruments had long become obsolete, for these small ones could be used for all the purposes for which a large one had been required, and gave better results.
I examined one of them and found, to my surprise, that it embodied the very ideas that I had long been trying to carry into effect. With this view I had made many experiments, as it seemed to me that it ought to be possible to construct an instrument of moderate and convenient dimensions which would show as much as our monsters will show, and yet be capable of being used with low powers when occasion required. I had endeavoured to attain this result by the aid of electricity, but failed to do so. Evidently I had missed something, but here was the thing itself in successful working, as I found upon testing it.
On looking at some drawings of Saturn, which were hanging up in the observatory, I noticed that this planet was depicted with two faint outer rings which do not appear on our drawings of the planet. One of these rings has, however, been discovered by M. Jarry-Desloges, but the outermost ring is still unknown to our observers. This ring is a very broad one, its particles being widely scattered, hence its extreme faintness.
The Martians have also discovered two planets far beyond the orbit of Neptune, and their knowledge of the other planets and also of the sun and the stars is far ahead of ours.
I was also shown a comet which had recently become visible through their telescopes, and found from its position that it was undoubtedly Halley's comet, for which our astronomers were so eagerly watching. I wondered whether any of them had been fortunate enough to discover it early in August, as the Martian astronomers did. Its last appearance was in the year 1835.
John remarked that "He thought Halley's comet might be termed 'Britain's Comet,' for several of its appearances had coincided with the occurrence of very important events and turning-points in our national history, such as the Battle of Hastings, the Reformation, &c.," and he added, "as it will be a conspicuous object in our skies in 1910, I wonder whether any important event will occur in our country? In 1835, when it last appeared, we had a political crisis!"
"Well, John," I replied, "I do not attach much importance to comets as affecting mundane affairs; we have got rather beyond such beliefs as that. Besides, when we left England early in August things were going on all right in our political world, and there was no indication of any serious crisis."
"Still," said John, "it would be rather curious if we did have a crisis next year; and I should not be surprised!"
As we were walking home next day, M'Allister suddenly tripped over some little projection and fell prone to the ground. John ran to his assistance and raised him up, at the same time asking "If he were hurt?"
"No, not at all," said M'Allister; "I seemed to fall so lightly that I scarcely felt it when I touched the ground."
"Ah, M'Allister!" I exclaimed, "if you had fallen like that upon our earth, I think you would not have come off quite scatheless. You see, upon Mars the gravitation is much less than on the earth, being only three-eighths of what it is there, so one does not fall so swiftly, nor so heavily, as on the earth.
"You can prove that very easily. Just take up a stone and hold it out higher than your head, and let it fall; at the same time note, by the second hand of your watch, how long it takes for the stone to reach the ground."
He did so, and said that "As near as he could tell, the stone was just about one second of time in passing from his hand to the ground."
"Just so," I replied. "On Mars a falling body only moves through a space of about six feet in the first second of time. On the earth, however, the gravitation is so much greater that a falling body passes through a space of a little over sixteen feet during the first second.
"In addition to that, although you weighed twelve stones when on the earth, you only weigh about four and a half stones here upon Mars. Now you can understand why it was you seemed to fall so lightly."
"Yes, Professor," he replied, "and I'm glad I fell here, and not upon the earth!"
Then, picking up the stone again and throwing it high in the air, he watched its fall, and turning to me, remarked, "Professor, you were quite right; that stone seemed to be quite a long time coming down again, much longer than it would have been on our own world."
"Well, M'Allister," I replied, "now you know for certain that upon a small planet gravitation really is much less than upon a larger planet of the same kind.
"That's another little wrinkle for you, and you have found it all out through tripping over a stone!"
"Losh, mon," replied he, "I seem to have learnt something almost every day since I have been here; even a tumble down teaches me something!"
I then drew his attention to the birds flying near us, and pointed out that they had a much wider spread of wing than our birds have, and that this was owing to the fact that the air being so thin a wide spread of wing was absolutely necessary to support them in the air and enable them to fly. I further explained that, if the gravitation upon Mars were as great as upon the earth, the birds' wings must necessarily have been still larger, as the pull of the planet would have been so much the greater, and would thus have prevented the birds from flying at all in such thin air if their wings had been small.
"M'Allister," I then remarked, "you will, no doubt, have noticed the same thing with regard to those large and beautiful butterflies we have seen. Why, the outspread wings of the largest must have measured ten or twelve inches across, and many of the smaller varieties were more than six inches across. I wonder what our naturalists would say if they could see some specimens of these large and splendidly coloured insects!"
"Well, Professor," he answered, "I never saw such large butterflies anywhere else, not even when I was in the tropics on our own world. It had never occurred to me that gravitation, or even the density of the air, had anything to do with their size. Even now I do not understand how it is the small insects are able to fly, for they are heavy for their size, and do not possess very large wings, yet they can move very swiftly."
"Let me explain then," I answered. "Large birds can only move their wings with comparative slowness, and it is therefore necessary that their wings should be large to enable them to keep their balance and be able to fly. Their wings are somewhat in the nature of aeroplanes, and they shift them to different angles to take advantage of the varying currents of air.
"In the case of humming-birds and small insects, the wings are capable of intensely rapid vibrations, so rapid indeed that, when flying, the wings are almost, if not quite, invisible. This intensely rapid movement enables them to fly, and is somewhat analogous to the rapid movements of the vertical spiral screws, which you have seen on some of the Martian air-ships that screw their way up into the air.
"Such rapid movements would not be suited to larger creatures, because their muscular powers would have to be so enormously great that their bodies would require to be larger and heavier in proportion. They would thus be very unwieldy."
CHAPTER XXIII.
I HAVE A SERIOUS TALK WITH JOHN.
For some days past it had been becoming more and more evident to me that John was quite infatuated with Siloni, and also that she was not unwilling to receive his attentions. I could, therefore, no longer remain a silent spectator, so took the first opportunity of our being alone to broach the subject to him.
I began by saying, "John, have you any idea of remaining upon this planet for the rest of your life?"
He looked round at me and flushed up. Then, after a little hesitation, said, "No, Professor; why do you ask such a question as that?"
"Because, John," I answered, "it seems to me a very necessary question to ask. If you are going away from here very shortly, what is the meaning of your attentions to our handsome young friend Siloni? You must excuse my speaking of this, but I do not like to see you placing yourself in a false position. Don't you think it would be wise to see a little less of the lady in question during the remainder of your stay here?"
"Well, perhaps so, Professor," he replied rather reluctantly. "I never thought it would come to this with me, considering that I am now on the wrong side of forty. It has been said that a man does not know what love really is until he has passed that age, and certainly I never did. Candidly, Professor, I must confess that I am very hard hit; and I know pretty well now what it means to be over head and ears in love with the most charming girl I ever met in my life!
"Do not imagine I have not seen the difficulty of the situation; but, really, I am puzzled to know what to do for the best. I am sure that dear girl would have me, and if I take her to England----"
"John," I interrupted, "my dear boy, what can you be thinking of? How is it possible that you can take to England as your wife a Martian girl, who stands considerably over seven feet in height!
"Even supposing it were possible that she could live in the atmosphere and climate of our country, she would be entirely isolated from every one, and, moreover, would be an object of public curiosity wherever she went.
"It would really be most unjust, humiliating, and cruel to Siloni; and you would be made very unhappy owing to the way she would be treated."
John looked down and fidgeted his feet about on the floor as he pondered in deep thought for some minutes, then looking up at me, he said, "I suppose you are right, Professor; you generally are; and that I have been rather foolish; but really I was thoroughly caught in the toils before I realised it. Now, what would you advise me to do in the matter?"
"I should advise you now as I did at first," I replied--"see less of Siloni. I suppose you have not actually spoken to her on the subject yet?"
"Oh no," he answered quickly, "I have not gone so far as that; but Siloni must be aware of my regard for her."
"Well, that being the case," I said, "you cannot very well say anything now, for it would place her in a most awkward and unpleasant position. You cannot tell her you were going to propose, but have thought better of it. Your only course, John, is to keep away from her as much as possible without appearing to do so intentionally."
"But won't she think it very strange behaviour on my part if I avoid her now, after being so much in her company?" he asked desperately, as if in hopes that I might not press him to give up the idea of continuing as before.
"No, John, I do not think so," I replied. "You know she is a Martian, and if she has not already some intuition of the situation, the very next time you see her this trouble will be on your mind, and she will become aware of the exact position of affairs; and I have no doubt she will accept the situation, though it will probably cause her considerable pain. You should have thought of all this sooner, my boy. It is a great pity this has happened, but there is no help for it now, and no other honourable way out of it that I can see. I am, however, extremely sorry for you both."
"Thank you, Professor," he exclaimed, grasping me fervently by the hand; "but it is very hard luck indeed."
He was very quiet and self-absorbed for several days after that, but things turned out just as I anticipated. The next time he and Siloni met and conversed together, she became aware of the change in him, and divined the reason of it. She said nothing, but he knew she understood; and, except that she was quieter, she never made any difference in her behaviour towards him when they met occasionally afterwards.
So, though I was sorry in some respects, I was very glad that this awkward matter was settled.
CHAPTER XXIV.
THE MARTIAN SEASONS.
Our earliest records of Mars date back to a very remote period, viz. 2300 years before the birth of Christ! Professor Hilprecht, in the course of his investigations on the site of the ancient city of Nippur, made extensive excavations, and dug down and down through the ruins until he had penetrated through those of no less than sixteen different cities, which, at various times, had been built one over the other. He unearthed the famous Temple of Bel, together with its great library, consisting of over 23,000 tablets, containing the chronicles of Bel.
When a number of these tablets had been deciphered, they were found to contain a complete system of philosophy, science, and religion, and proved that those ancient people knew many things about astronomy, and in some of the fundamental matters would not have much to learn from astronomers of the present day. These tablets contained, amongst other things, records of observations of Mars! It is claimed that Chinese records go back to a still more remote date.
Since the discovery of the telescope our knowledge of Mars has gradually extended, and its general surface configuration is now well known to all students of the planet.
[Illustration: From a Globe made by M. Wicks Plate XIII MARS. MAP VI.
"Syrtis Major" is seen on the extreme left just below the Equator. "Sabaeus Sinus" is again in view just to the right of the centre, thus this map completes the circuit of the Globe of Mars.]
The polar snow-caps were early depicted on drawings, also some of the dark areas; especially the striking one which has been known as the Kaiser Sea and the Hour Glass Sea, but is now usually termed Syrtis Major. It has an outline somewhat resembling that of India; and, if we include the southern portion, it is nearly as large in area.
Our maps of Mars are now practically uniform as regards the naming of the places marked upon them. Formerly this was not so, as each country had its own map and the places marked thereon were named after different astronomers, and usually after those belonging to the country in which the map was prepared. Much confusion arose from this practice, because the same spot on Mars might have a different name on each map; thus it was difficult to identify any particular spot when only the name was known.
Some international jealousy also arose owing to the patriotic desire of observers to identify particular spots upon Mars with the names of the great men of their own country.
To remove this cause of friction and misunderstanding a system has now been almost generally adopted of giving classical names to Martian markings. Some of these are of portentous length and strange spelling, but still the adoption of a uniform nomenclature has been a great convenience to observers and others who have occasion to use or refer to the maps.
On looking at a complete chart of the planet it will be seen that the largest area of dark patches (which are believed to be areas capable of supporting life) is situated in the southern hemisphere, and that several of these are wedge-shaped, with the points trending northward. On the earth it is just the opposite, the largest area of land being in the northern hemisphere, and the wedge-shaped masses trend southward.
Our earth's surface comprises an area of about 193,000,000 square miles, of which some 143,000,000 square miles are water, and the remaining 50,000,000 square miles land.
Mars has a surface area of about 56,000,000 square miles, about 35,000,000 square miles being desert, and the remaining 21,000,000 square miles land which may be habitable, as most of it is covered with vegetation. There are no large areas of water anywhere upon Mars. This calculation, however, makes no allowance for the lines of vegetation which cross the desert, and contain canals, and, with the oases, may have a very large population.
From the 50,000,000 square miles of land upon the earth must be deducted the very large areas which are frozen during the greater part of the year, and also the large areas which are deserts or bare rocks. This would probably bring down the really habitable area to about 30,000,000 square miles.
Making a similar deduction in the case of Mars, but remembering that more of the regions near the poles would be habitable during part of the year than is the case on the earth (as there is practically no permanent glaciation and the temperate zones extend nearly to the poles) the habitable area would be reduced to, say, 15,000,000 square miles.
It will thus be seen that although the total surface area of Mars is only rather more than one-quarter of that of the earth, the area of its habitable land, even under its present unfavourable circumstances, amounts to about half of the habitable area of the earth.
Looking at Mars from this point of view, it does not contrast so unfavourably with the earth as is usually thought, especially when it is remembered how small a proportion of the earth's area is really populated.
Were it not for the great eccentricity of the planet's orbit, the seasons upon Mars would be very much the same in the different zones as they are on our world, as the inclination of the planet's equator is only very slightly less than that of the earth. According to the latest determination, the inclination in the case of Mars is 23 and 13'.
As the Martian year is nearly twice as long as ours (being 668 Martian days, which are equal to 687 of our days) the seasons are of course proportionately longer in duration. The eccentricity of the orbit, however, causes a much greater difference between the lengths of summer and winter in the two hemispheres.
In the northern hemisphere of Mars, spring lasts 191 Martian days; summer, 181 days; autumn, 149 days; and winter, 147 days.
In the southern hemisphere spring lasts 149 days; summer, 147 days; autumn, 191 days; and winter, 181 days.
Thus, in the northern hemisphere spring and summer together amount to 372 days, and autumn and winter to 296 days.
In the southern hemisphere, however, spring and summer have 296 days, whilst autumn and winter last 372 days; so that the winter period of the year is 76 days longer than in the northern hemisphere.
On the earth the winter portion of the year is seven days longer in the southern hemisphere than it is in the northern hemisphere.
For this reason, our south polar snow-cap is larger than the north polar cap; and we should naturally expect to find a similar condition upon Mars, only greatly accentuated. Astronomical observation shows that this is the case, for while the northern snow-cap on Mars attains a maximum diameter of slightly under 80, the southern snow-cap attains a maximum diameter of over 96. The snow-caps are not perfect circles, but irregular in shape, and are, moreover, not exactly opposite to each other.
Notwithstanding its much greater area the southern snow-cap melts to a greater extent than the northern snow-cap does, owing to the intensity of the heat at the melting period. The northern snow-cap usually melts until the diameter is reduced to about 6, whilst the much larger southern cap may be reduced to about 5. In the year 1894 it disappeared entirely! The summer must have been unusually hot.
So far as can be gathered from the records of our whaling and polar expeditions, it would appear that our north polar snow-cap is from 20 to 30 in diameter when at the minimum; whilst the southern snow-cap is nearly 40 in diameter when smallest.
We had arrived upon Mars on the 24th of September 1909, according to terrestrial reckoning; but according to the Martian date it was then the 26th of June in the southern hemisphere, where Sirapion, our landing-place, is situated. The season was, therefore, midsummer, and as Sirapion is in latitude 25 south and in the sub-tropical zone, the temperature was fairly high. The mornings were much more clear and brilliant than those on our earth; the warmth and general "feel" of the air at that time reminding me very much of what it is like in the south of England between seven and eight o'clock on a hot sunny day. Those who enjoy an early morning walk know how delightful and exhilarating it becomes towards that time. There is neither chilliness nor uncomfortable heat; one feels a delightful sense of freedom and that it is good to be alive. This is really the best and most enjoyable time on a summer's day. On Mars there was rather more warmth but a greater sense of exhilaration. Of course, from near noon to about 3 P.M. it was much warmer.
Usually a lovely rosy effulgence is seen in the atmosphere in the mornings and evenings. As a rule, sunrise and sunset effects are much more ethereal and more beautiful than those on the earth, the tints being more delicate and the whole appearance of the sky less broadly marked. It is as the difference between the crude broad effects of a coloured poster and the delicate effects of a highly-finished painting.
What, in our sunsets, would appear a deep golden colour appears on Mars as a delicate pale gold, merging into bright silver. What with us is a carmine or deep rose, in Martian skies becomes a beautiful rose-pink; whilst the darker, or Indian, red seen for some time at the latter period of our sunsets is carmine in the Martian sky, and Indian red only appears just at the last.
These tints are seen when the skies are of their normal clearness, but after the occurrence of a great sand-storm in the desert and the upper air has become filled with fine sand particles, the Martian sunsets are equal in variety and depth of colour to anything seen on our earth during the months immediately succeeding the Krakatoa eruption. Those strange and intensely coloured sunsets will doubtless be remembered by my readers who had the good fortune to see them during the many months when they were visible after that great volcanic outburst in the year 1883.
Sand-storms have been unusually prevalent on Mars during the present summer, passing over large areas of country and obscuring the sun for considerable periods; so we have had several phenomenal sunsets afterwards.
As the time passed on the days became cooler--the evenings being considerably more so than on our earth in August, and twilight was very much shorter. Towards the end of the Martian August evening dews began to be succeeded by slight hoar frosts.
The heat in the tropics is not nearly so intense as on the earth. On the other hand, in the high latitudes near the poles, the summer temperature is higher than in similar latitudes on the earth, because upon Mars there is no permanent glaciation except right at the poles.
We have, of course, seen the Martian polar stars. The axial tilt of the planet being less than that of ours, and in a different direction, and its orbit being inclined 1 and 51' in regard to the earth's orbit, it follows that the poles of Mars must point to a different part of the sky, and a considerable distance from our polar stars.
In the northern hemisphere of Mars the polar star is a small one marked on our maps in the constellation of Cepheus, and it is almost on the boundary between that constellation and Cygnus. The pole star lies nearly in a line joining the brighter stars [alpha] Cephei and [alpha] Cygni.
The south polar star is a small one marked [symbol] in that part of the large constellation of Argo Navis which is termed Carnia.
Although the polar stars are very small, they shine more brightly in the Martian skies than the north polar star does to us, and are therefore more easily seen.