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 lat.i.tude 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, pa.s.sing over large areas of country and obscuring the sun for considerable periods; so we have had several phenomenal sunsets afterwards.

As the time pa.s.sed 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 h.o.a.r frosts.

The heat in the tropics is not nearly so intense as on the earth. On the other hand, in the high lat.i.tudes near the poles, the summer temperature is higher than in similar lat.i.tudes 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...o...b..t being inclined 1 and 51' in regard to the earth's...o...b..t, 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.

CHAPTER XXV

MANY THINGS SEEN UPON MARS--I RECEIVE SOME NEWS

During the remainder of our stay upon Mars we visited almost every important place upon the planet, either by means of air-ships, motors, or by travelling along the main ca.n.a.ls in splendidly equipped electric boats.

We pa.s.sed through the whole length of the Eumenides-Orcus, from its starting-point on the Phoeniceus Lacus, in the southern hemisphere, to the Trivium Charontis, in the northern hemisphere--a distance of 3540 miles, this being the longest ca.n.a.l on the planet. We visited the Solis Lacus, or "Lake of the Sun" (an area larger than England), situated in the southern hemisphere, which has usually been seen by our observers as a large dark patch, oval in shape. Indications of changes in this area were, however, noted at the time of the opposition in 1907; and it is not improbable that further alterations will be seen shortly.

Numerous important towns exist upon this area, and several ca.n.a.ls connect it with surrounding areas.

We visited the north pole in our air-ship, and saw the snow falling thickly, and rapidly adding to the size and thickness of the snow-cap, it being winter time. We visited the south pole and watched the fast-melting snow (the cap being almost at its minimum size) and the distribution of the resultant water down the various broad channels which conduct it to the ca.n.a.ls, from whence it is carried all over the planet.

When it is spring in the northern hemisphere the winter snow-cap at the north pole will begin to melt in like manner, and the water be distributed in a similar way. The melting begins about the 1st April and lasts till July, and sometimes considerably later in the year.

Thus, during the Martian year there are two distributions of water--one from the north pole and one from the south pole; and the growth of vegetation follows the pa.s.sage of the water as it flows downwards from the poles to the equator.

On our earth vegetation progresses in an exactly opposite direction.

Beginning near the tropics, where it is always summer, as the sun pa.s.ses northward of the equator so vegetation gradually appears and develops onwards towards the north pole. It is exactly the same in the southern hemisphere; after the sun crosses the equator into the south the vegetation grows and spreads towards the south pole.

The reason of this is that on the earth the supply of water by rainfall and snows is abundant, and it only requires the warmth of the sun to cause vegetation to spring up again at the proper season when the winter has pa.s.sed.

On Mars the sun has the same action, but until the water comes down from the poles and furnishes the necessary moisture, the sun can produce no effect and there can be no fresh vegetation. Thus, on Mars, the flow of water is the determining factor, and vegetation follows its course from the poles towards the equator.

Observation shows that this is the case, and it has formed one of the strongest arguments in support of the idea of water conveyance by means of artificial ca.n.a.ls. The opponents of the ca.n.a.l theory seem carefully to avoid any mention of this argument.

While we were watching the melting of the snow at the south pole, I mentioned to Merna and Tellurio, who accompanied me, that one of our scientific men, relying for support on a speculation by a lady writer, had arrived at the conclusion that the snow-caps could not possibly supply anything like the amount of water required. The writer in question had stated that the maximum area of the southern snow-cap was 2,400,000 square miles; and, a.s.suming it was composed of snow of an average depth of twenty feet, this would only give an average depth of about one foot of water over its whole area.

The whole of the dark areas on the planet covered at least 17,000,000 square miles, and as this was seven times the area of the snow-cap, it followed that the dark areas could not be covered with more than two inches of water. From this scanty and inadequate supply of two inches of water allowance must be made for an enormous loss by evaporation; so, as the writer said, "the polar reservoirs are despoiled in the act of being opened."

Tellurio at once settled the matter by saying, "Mr. Poynders, it is a very pretty theory, but, unfortunately for its supporters, it is entirely wrong, the figures being inaccurate, and the estimate of the extent of the area to be supplied, as well as the amount of water available, is made under a complete misapprehension of the facts."

[Ill.u.s.tration: _From a Globe made by M. Wicks_ Plate XIV

MARS. MAP VII

The white area at the top of this map is the south polar snow-cap, at about its usual maximum size. In some hard winters it attains a diameter of considerably over 100 degrees.]

"The maximum area of the south polar snow-cap is usually more than 10,000,000 square miles instead of less than 2,500,000 as stated, but it is sometimes still greater during a hard winter. Then, where did the writer acquire the notion that the whole of the dark areas had to be covered with water? Only the ca.n.a.ls and trenches have to be filled, and, at the highest computation, these would cover only 2,250,000 square miles! So even accepting her average of twenty feet depth of the snow (which would give about one foot of water over the whole area of the snow-cap), there would still be sufficient water to fill every ca.n.a.l and trench upon our planet to a depth of nearly four feet six inches.

"Let us suppose we have 700 series of ca.n.a.ls, each averaging 1400 miles in length, and each series having an aggregate width (including the area of the irrigation trenches) of 2-1/4 miles. You will see that gives about 2,250,000 square miles to be covered with water. My estimate of the area to be covered is, however, much in excess of the real amount, as the average aggregate width of the series of ca.n.a.ls would be less than I have a.s.sumed, and the trenches are shallow.

"I must also point out that only a small proportion of the whole number of ca.n.a.ls would be in use at any given time, and the depth of the polar snows averages considerably more than twenty feet; so a very much greater depth of water can be secured in those ca.n.a.ls which are in use.

The main ca.n.a.ls which are used for navigation purposes are, of course, much wider and deeper than the irrigation ca.n.a.ls. In the hotter regions many covered compensation reservoirs are provided, and these make good the wastage caused by excessive evaporation where pipes cannot be used."

"Thank you, sir," I said; "the information you have now given me entirely confirms the figures as to the area of the snow-cap, &c., mentioned by Professor Lowell, but as regards the depth of the snow and the size of the area to be covered, he has with scientific caution refrained from estimating to the full extent which the facts you mention seem to warrant. In addition to this, no allowance has been made for the water derived from the northern snow-cap."

Thus vanished the theory which was supposed to support the view that the ca.n.a.ls must be hopelessly unworkable, and could never be of any use for irrigation purposes.

It had also been argued that no intelligent beings would construct ca.n.a.ls if the planet were generally flat, as it would only be necessary to let the water flow over the surface as far as it would go, and thus irrigate the parts reached by the water; whilst if it were not flat, the ca.n.a.ls could not be constructed at all.

I asked Tellurio "What he thought of this suggestion?"

He replied, "Well, sir--here we have a planet believed to possess only a very scanty supply of water, which must require the most careful husbanding and economy in distribution; yet it seems to have been calmly suggested that we would deliberately waste the precious fluid by allowing it to flow at random over the small portion of our land which it would reach, where it might or might not be required! Our engineers, I may say, are quite capable of overcoming any difficulties arising from inequalities of the ground.

"If, as has been contended, the loss by evaporation would be so great in ca.n.a.ls where the water is fairly deep as to result in depletion of the supply, it is clear there must be a hundred times greater loss from the same cause if the water is allowed to spread in a very shallow pool over a large area where it would be totally unprotected from the sun! Then, again, every part of our planet not reached by the water would become desert.

"No, sir," Tellurio added, "the Martians are far too intelligent to waste the water in this fashion: hence their ca.n.a.l system by which the water is economically distributed where required, and also protected from undue evaporation. It must not be forgotten that our ca.n.a.ls are also means of communication across the deserts, and without them distant parts of the planet would be entirely isolated from the rest of our world, except for our air-ships.

"Our ca.n.a.l system has been a matter of slow growth and development.

Beginning with the straightening of the beds of old rivers and narrow channels connecting seas, the ca.n.a.ls were then constructed where they were most needed; but as time pa.s.sed on, and our water supply from rainfall became less and less, we were convinced of the necessity of adopting a complete system of ca.n.a.lisation in antic.i.p.ation of the time when our polar snows would be our only source of supply. This was gradually carried into effect, and even now additional ca.n.a.ls are being constructed to meet the requirements of places not reached by existing ca.n.a.ls.

"In order to secure the return of the water to the poles, and so ensure a future supply, it is absolutely necessary that, wherever possible, the water should be conveyed in open channels so as to allow evaporation to take place, otherwise much would be lost by soakage into the soil."

"Thank you, sir," I said; "those statements meet another objection which has been urged against the possibility of the ca.n.a.ls existing; it apparently being a.s.sumed that the whole system must have been carried out simultaneously, and that the population of Mars would have been much too small to admit of that being done."

"Our population is by no means small, sir, having regard to the size of our planet; and the Martians, as intelligent beings, have always been in the habit of looking well ahead to ascertain what provision would be required to satisfy our prospective needs. Your people take far too narrow a view of these matters."

Thus many controversial matters were satisfactorily cleared up by statements of actual facts.

During our journeys over the planet we came across a large number of ca.n.a.ls in different parts which have apparently not yet been discovered by our observers. These were not all narrow lines of ca.n.a.ls, and many of them were double ones, so our observers have more work yet before them in finding out these lines and recording them on their charts.