by Mark Wicks
CHAPTER IX
A NARROW ESCAPE FROM DESTRUCTION--I GIVE SOME PARTICULARS ABOUT MARS ANDMARTIAN DISCOVERY
Things now went on quietly and, in fact, rather monotonously for severaldays; and then we met with another rather startling experience.
We were all sitting together in our living-room on the 9th of September,whiling away the time in a game of whist, and, as it was the finalrubber and we were running very close together, we were quite absorbedin the play; although, of course, it was a dummy game.
Suddenly we heard a most tremendous crash, apparently from theright-hand side of the air-chamber, the vessel giving a violent lurchsideways, then shivering and trembling from end to end. The crash wasimmediately followed by a sharp rattling on the top and side of the_Areonal_, just as though a fusillade of good-sized bullets had beenfired at us.
"My word! whatever's that?--one of the cylinders must have exploded,"cried M'Allister, jumping up in alarm and running into the air-chamber.We followed him, and looked all round the room at the different machinesand apparatus, but could find nothing wrong.
John, chancing to look up, however, at once noticed a large bulge onthe inner shell of the vessel, high up on the right-hand side; and then,turning to me, pointed it out, saying, "I think, Professor, it is prettyclear now what has happened."
"Yes, that huge bulge explains itself," I replied; "undoubtedly afair-sized meteoric stone has collided with our vessel. It is veryfortunate that the stone was not much larger, or there would have beenan end to the _Areonal_ and to us as well. These meteorites travel atsuch tremendous speed that, on entering the earth's atmosphere, theybecome incandescent owing to the friction of the air, and, unless verylarge, are entirely consumed and dissipated into dust before they canreach the earth. Those that do fall are always partially fused on theoutside by the tremendous heat generated by the friction of ouratmosphere. These meteorites are what people call 'shooting stars,' andmany are under the impression that they really are stars, until thedifference is explained to them."
John said, "We ought to congratulate ourselves upon such a lucky escapefrom annihilation; for had our vessel been constructed of any metal lesshard and tough than our 'martalium,' and without a double and packedshell, it must have been wrecked and entirely destroyed by the shock ofthe tremendous concussion it had sustained. Even the very metal of thecasing might have been completely melted by the intense heat generatedby the impact of the meteorite."
"Heh, mon!" exclaimed M'Allister; "it's all very well talking about ourlucky escape, and putting it all down to your own cleverness indesigning and constructing the _Areonal_; but you should rather givethanks to Providence for saving us, and for enabling you to take theprecautions you did. I say, 'Thank God!'" he remarked, and he solemnlyraised his right hand as he spoke.
"Quite right, M'Allister," replied John: "we are all too prone to creditourselves with more than we are entitled to. At the same time,M'Allister, you must remember that we Englishmen recognise as fully asyou do the over-ruling power of Providence, although we may not be quiteso free in speaking about it in ordinary conversation."
"Yes," I added, "you may be quite sure, M'Allister, that we are equallyas grateful as yourself for the mercy which has preserved us all from anawful death. My very first thought on realising our extremely narrowescape from destruction was to say 'Thank God!' but I did not say italoud as you did. It is in matters like these that people differaccording to their temperament and training; and it is not safe to judgeanother because, in any particular circumstances, he does not act inprecisely the same way as we ourselves would."
Thus we travelled on and on, each day bringing us more than two millionmiles nearer to our destination. Mars was apparently increasing indiameter the nearer we drew to it, and the dark blue line around thesouth polar snow-cap, indicating the lake of water from the meltingsnow, was very conspicuous. The snow-cap had recently decreased rapidly,being now near its minimum and irregular in shape, for in the southernhemisphere it was now late in June. Pointing to the planet, I remarked,"There is our destination! We see it now as the poet pictured it for us,and the words of Dr. Oliver Wendell Holmes are very appropriate to thepresent circumstances:
'The snow that glittered on the disc of Mars Has melted, and the planet's fiery orb Rolls in the crimson summer of its year!'"
On the 18th of September we passed between the earth and Mars, nearly ina line with the sun. On that date Mars was in perigee, or at its nearestpoint to the earth during the present year. Its distance from the earthwas then 36,100,000 miles, and it will not be so close again until the24th of August 1924. We could not see the earth, as its dark side wasturned towards us, and it was also lost in the brilliancy of the sun.
At this date we had travelled 88,000,000 miles since we left the earth,yet we knew it was there, level with our vessel, and only about29,000,000 miles distant on our left hand, whilst Mars was only7,000,000 miles from us on our right-hand side.
Our position now was as follows:--Taking an imaginary line drawn fromthe _Areonal_ to Mars as the base line of an isosceles triangle, we weremoving along the left side of the triangle, and Mars was moving in aslightly curved line along the right side. Our paths were thereforeconverging, and if all went well we should both meet at the apex of thetriangle on the 24th September, as we had originally intended.
We therefore had six clear days to cover the distance of less than12,000,000 miles, so we should have sufficient time to slacken speed atthe end of the journey. (See the chart.)
Mars was rapidly growing in size and brightness, for the distancebetween the planet and the _Areonal_ was quickly diminishing as ourpaths converged, and the various markings on its almost full round discformed the subject of continual observation and conversation. We hadnoticed on several occasions a mistiness on some parts of the planet,which I attributed to the vapours raised from the canals by the heatedatmosphere.
On the 21st of September, when we were all enjoying a smoke in the"evening," and conversation had dragged somewhat, John started us off ona fresh tack and gave us something to talk about for a very long time.
He winked at M'Allister and, looking at me with a knowing smile, said:"Professor, as we are nearing our destination it might perhaps be wellif you now gave us some detailed information respecting the planet,similar to that which you gave us when we were approaching the moon. Itwould be both interesting and useful; for we should learn much more froman orderly statement of the facts than we should from several long butdesultory conversations."
"Yes, Professor," chimed in M'Allister, "I'm quite ready to learnsomething definite about Mars, for I can't say I really know much aboutit at present."
"Very well then," I replied, "it is upon your own heads, and if you arewilling to listen to a rather long story, I am prepared to do thetalking. Please remember, however, that it will require some time tomake matters clear and understandable."
"Fire away, mon," cried M'Allister, "we will listen as long as you careto talk."
So I began--"Mars, as no doubt you are aware, is a much smaller planetthan the earth, its diameter being only 4220 miles, which is a littleless than twice the diameter of our moon.
"It would require nine and a half globes the size of Mars to make oneglobe the size of the earth; and even then it would not be so heavy,because the average density of Mars is only about three-fourths of thatof the earth. Mars is the next planet outside the earth's orbit, so isthe fourth from the sun. The orbit in which Mars moves in its journeyround the sun is very much more eccentric than the earth's orbit; infact it is more eccentric than the orbits of any of the larger planets.As a consequence, the planet's distance from the sun varies greatlyaccording to the particular part of the orbit in which it may be moving.Its mean distance from the sun is 141,500,000 miles, its greatestdistance over 154,000,000, and at its nearest approach to the sun, or'perihelion,' as it is called, its distance is only 129,500,000 miles.Mars travels in its orbit at a mean rate of 15 miles a second.
"
As its orbit is also eccentrically placed in relation to the earth'sorbit, it follows that its nearest distance from us in any particularyears may vary greatly. The nearest possible approach it can make inregard to the earth is a little under 35,000,000 miles; when at theopposite point of its orbit its nearest approach is about 62,000,000miles from the earth. As the years of Mars and the earth differ greatlyin length, and the two planets move at different speeds, the veryfavourable oppositions can only occur about once every forty-five years;though a comparatively near opposition occurs about every fifteen years.Such a close approach we have just witnessed, and it will be fifteenyears before Mars is again so near to the earth!
_CHART: showing the Orbits of the Earth and Mars, andthe relative positions of the two Planets, during the years 1909-10.Mars passed over the dotted portion of its Orbit in the year 1910._
_The Outer Circle is the Orbit of Mars, and the inner Circle is theOrbit of the Earth. The Seasonal points on both Orbits show the Seasonsin the Northern hemisphere. In the Southern hemisphere the Seasons arereversed, "Summer" occurring at the point marked "Winter," and "Spring"at the point marked "Autumn," &c. &c._
_The dotted downward line on the left-hand side shows the course takenby the "Areonal", which left the Earth on the 3rd of August andarrived at Mars on the 24th of September. * Shows the point reachedwhen John wished to turn back; and the lower dotted line, thealternative course then suggested._
_The long dotted line running upwards to the Spring Equinox of the Earthshows the course taken on the homeward Voyage._
_Drawn by M. Wicks._
Plate VII]
"The Martian year is equal to 687 of our days, but as the Martian daysare slightly longer than ours, this really represents 668 Martian days.
"The entire surface of Mars contains an area of about 56,000,000 squaremiles, which is about one-fourth of the area of the earth's surface.
"Its gravity is only three-eighths of the earth's gravity, thuseverything upon Mars would weigh proportionately lighter than on theearth, and the amount of labour required to do such work as digging orlifting would be lessened. There would, for the same reason, be greaterease of movement in walking, jumping, or running, and large bulkyanimals like our elephants could move with almost the same ease andfreedom as our goats.
"Theoretically, we should expect to find the atmosphere upon Mars verymuch thinner than our atmosphere, and actual observation proves this tobe the case. We are able to see details on the surface of Mars with verymuch greater distinctness than would be the case if its atmosphere wereas dense as ours. Moreover, clouds are comparatively rarely seen; andthe majority that are observed present more the appearance of clouds ofsand than rain clouds. Usually, also, they float very much higher abovethe planet's surface than our clouds are above the earth's surface; tenmiles high is quite an ordinary altitude, and some have been estimatedas quite thirty miles above the planet.
"Many theorists have attempted to prove that, owing to the planet'sdistance from the sun, and the thinness of its atmosphere, thetemperature of Mars must be very low, probably below freezing-point evenat the equator. Dr. Alfred Russel Wallace has gone further than this,and suggests that the temperature must be eighty degrees Centigradebelow freezing-point; that there is no water or water vapour on theplanet; and that it is quite impossible for life to exist there!
"However, as the result of delicate bolometric experiments, carefulcalculations, and consideration of conditions affecting the result whichhave not previously received so much attention, Professor Very hasarrived at a different opinion; and actual observation has shown thatthere is very little indication of frost outside the frigid zones. Evenin the polar regions it is at times evidently warmer than at the earth'spoles, because during the spring and summer the snow-caps upon Mars notonly melt more rapidly, but melt to a much greater extent than our polarcaps do. In 1894 the southern polar snow-cap of Mars was observed almostcontinuously during the melting period, and it was actually observed todwindle and dwindle until it had entirely disappeared. It is ratherstrange to think that we know more about the snow-caps of thatfar-distant world than we do about those on our own earth.
"Owing to the lesser gravity on Mars the snow and ice which forms thecaps would certainly be lighter and less closely compacted than the snowand ice upon our earth; but it is quite clear that it could not melt toany extent unless the temperature remained above freezing-point for aconsiderable length of time.
"It has, however, seriously been contended that the Martian polar capsare not snow at all, but frozen carbon dioxide--the poisonous dregs ofwhat once was an atmosphere. Carbon dioxide, however, melts and becomesgaseous almost suddenly, but these polar snow-caps melt gradually,exactly as frozen snow would; so this theory fails altogether to fit thecircumstances.
"Moreover, the water which accumulates all round the base of the meltingsnow-cap has been carefully observed on many occasions, and in the earlystage of melting it appears blue in tint, but later on, as upper layersof snow dissolve and those nearer the soil are reached, the waterpresents a turbid and muddy appearance; exactly what might be expectedwhen water has been contaminated by the surface soil.
"Dr. Alfred Russel Wallace declines to accept the blue tint as any proofthat the liquid is water, and contends that shallow water would notappear that colour when viewed from a distance. You will, however, haveobserved that the water in all our shallow reservoirs appears intenselyblue when observed from any distant and elevated point of view. It seemsto me that when, as in the case of Mars, we have a very thin atmosphereladen with sand particles, we have exactly the conditions which wouldproduce a very blue sky, and cause the water to appear a deep bluecolour when viewed from a distance.
"It is also contended that water cannot be present on Mars, because noneof our skilled spectroscopists has yet been able to demonstrate by thespectroscope that there is any water vapour in the Martian atmosphere.
"This, however, is generally acknowledged to be a very difficult anddelicate operation; and, in any case, it is purely negative evidence,and cannot be accepted as final. I feel quite confident that sooner orlater a means will be found of definitely proving the presence of watervapour upon Mars by the aid of the usual lines in the spectrum. Thereare too many evidences of its presence, such as clouds, hoarfrost, snow,and seasonal changes in vegetation, to warrant the rejection of the ideaof its existence merely because it has not been detected by theparticular means hitherto used by the spectroscopists.
"Mr. Slipher, of Flagstaff Observatory, has made many experiments withspecially sensitised photographic plates. He has taken severalphotographs of the spectrum of the moon and others of the spectrum ofthe planet Mars. The plates of the lunar spectrum show a darkening ofthe 'a' band, which indicates the presence of water vapour, and we knowthat is due to the water vapour in our own atmosphere. The plates of thespectrum of Mars show a much more definite darkening of the 'a' band,and Professor Lowell contends that this can only be due to water vapourin the atmosphere of Mars.
"Professor Campbell has, however, made similar experiments, and is ofopinion that Professor Lowell has been deceived by the water vapour inour own atmosphere. Thus the matter stands at the present time, and wemust await the result of further investigation before we can considerthe matter settled.
"I, however, regard it as a certainty that improved means willdefinitely show that water vapour undoubtedly exists in the Martianatmosphere, and it is not unlikely that other constituents of thatatmosphere may also be identified, and possibly even the relativequantities may be ascertained."
John here remarked that he had read of it being contended that lifecould not exist on Mars because as water would boil at a temperature ahundred degrees lower than it did on the earth, it would be impossibleto boil a potato properly, or make a good cup of tea. He thought,however, that if water boiled at such a low temperature, then theproportion of water vapour in the air would be increased, as evaporationwould be more rapid than on the earth.
"Undoubtedly
so," I replied. "The first argument, however, is very weak.For many thousands of years the people on the earth not only managed tolive, but attained a high state of civilisation, yet we have no reasonto believe that they ever ate potatoes or drank tea! Even in England wehave only known and used these articles for about three hundred years!The inhabitants of any world would be suited to their environments.
"The polar-caps on Mars are shown on very early drawings of the planet;but, up to the year 1877, little was known of the general surfacedetails beyond the fact that the general colour was orange-red,diversified by dark patches of blue-green in some parts, and somenarrow, serpentine markings here and there. All these markings are nowmuch more accurately drawn, as the result of more careful and continuousobservation. Sir William Herschel suggested that the red colour wasattributable to the vegetation of Mars being red, instead of green as onour earth; but it was generally considered that the red areas indicatedland and the dark areas water. The work of our modern observers has,however, resulted in a general revision of our ideas on these points.
"It had long been reasoned that, as the earth was accompanied by amoon, and Jupiter had at least four, Mars, the intermediate planet,might be expected to possess a satellite. The planet itself being small,its moon would probably be very small, and likely to be overlooked whenobserving with the telescope, because its light would be overpowered bythe light of the planet, which would make the telescopic field of viewvery bright. Up to the year 1877 the most powerful instruments had beenused without success in the search for the supposed satellite.
"In that year Mars made an exceptionally near approach to the earth, andProfessor Asaph Hall, of Washington Observatory, took up the search,using a splendid refracting telescope having an object-glass 26 inchesin diameter. The methods he adopted were rewarded with success, for hediscovered not only one, but two satellites of Mars, and they were giventhe names of Phobos and Deimos.
"Both these satellites are very close to the planet and extremely small,Phobos being less than 4000 miles from the planet's surface, and Deimosonly 12,300 miles from it. As seen in the telescope, they are very faintpoints of light which cannot be measured by ordinary means, and theestimation of their size was a matter of great difficulty.
"Professor Langley gives an interesting account of the endeavour toestimate their size by the amount of light reflected, as compared withthe light afforded by our own moon when full. It was a most difficulttask, as the comparison had to be made by means of tiny holes drilled inmetal plates; and for a long time it was impossible to find a workmanwho could drill a hole sufficiently small for the purpose, although oneof those employed had succeeded in drilling a hole through a lady's thincambric needle from end to end, thus converting it into a tiny steeltube. One would have thought such a feat impossible; yet what was nowrequired was a hole smaller than the one thus made through the tinyneedle."
"My word!" said M'Allister, "I would like to see the mon who did thatpiece of work, and shake hands with him; he must be a rare cleverfellow!"
"Yes," said John, "and I would like to see the drill he used; for such along and extremely slender tool, to be effective, must be as clever apiece of work as the steel tube."
"I may tell you," I proceeded, "that success was at last attained; andas a result of the comparison of our moon's light with that of Deimos,it was shown that if the general surface brightness of the latter wereequal to that of our moon, then Deimos must be only 18 miles indiameter, or about a 15,000th part of the area of our moon's disc.
"To state the matter in another way--supposing our moon were only 18miles in diameter, and was removed to the same distance as Deimos isfrom us, then it would appear only the very faint point of light thatDeimos appears when viewed through the telescope.
"By the same means Phobos, the satellite nearest to Mars, was estimatedto be about 22-1/2 miles in diameter. These dimensions, however, dependon the brightness of these satellites being exactly the same as thegeneral brightness of our moon; and later experiments have fixed thesizes as 36 miles for Phobos, and 10 miles as the diameter of Deimos.
"I will not detain you much longer on this subject, as we shall be ableto discuss it further when we arrive upon Mars; but I may now mentionthat, in one respect, the little satellite named Phobos is unique. It isthe only satellite we know of which revolves round its primary planet inless time than it takes the planet itself to make one revolution on itsaxis.[6]
"Mars revolves on its axis in 24 hours, 37 minutes, and 22 seconds, thusthe 'day' on Mars is nearly 38 minutes longer than our 'day.' Phobosrevolves round the planet in the very short period of 7 hours, 39minutes, and 14 seconds, and therefore makes more than three completerevolutions round the planet in the course of a single Martian day. Thepeculiar phenomena to which this very rapid motion gives rise, and thenumerous eclipses which occur, will be matters of great interest to usall when we reach Mars. Our moon, as you know, takes a month to make onerevolution round the earth."
"Professor," said John, "when we get to Mars, it will be rather acurious experience for us to see two moons shining in the sky at thesame time!"
"My word!" exclaimed M'Allister, "two moons shining at once! If I go outand see such a sight as that, I shall think the whisky has been a weebit too strong for me!"
"Well," replied John, "if your usual drink has the effect of making yousee double, take good advice, and leave the whisky severely alone whenyou are on Mars, or else you will be seeing _four_ moons all at once,and receive such a shock that you will never get over it!"
M'Allister laughed pleasantly as John said this. He is a real goodfellow, and takes all John's chaff with the utmost good-humour; but, injustice to him, I must say that, although he sticks to his nationaldrink like a true Scot, I have never once seen him any the worse for it.He knows his limitations, and always keeps within them.
