CHAPTER V.
THE ROMANCE OF THE MOON.
An observer endued with an infinite range of vision, and placed inthat unknown centre around which the entire world revolves, might havebeheld myriads of atoms filling all space during the chaotic epoch ofthe universe. Little by little, as ages went on, a change took place;a general law of attraction manifested itself, to which the hithertoerrant atoms became obedient: these atoms combined together chemicallyaccording to their affinities, formed themselves into molecules, andcomposed those nebulous masses with which the depths of the heavens arestrewed.
These masses became immediately endued with a rotary motion aroundtheir own central point. This centre, formed of indefinite molecules,began to revolve round its own axis during its gradual condensation;then, following the immutable laws of mechanics, in proportion as itsbulk diminished by condensation, its rotary motion became accelerated,and these two effects continuing, the result was the formation of oneprincipal star, the centre of the nebulous mass.
By attentively watching, the observer would then have perceived theother molecules of the mass, following the example of this centralstar, become likewise condensed by gradually accelerated rotation, andgravitating round it in the shape of innumerable stars. Thus was formedthe _Nebulae,_ of which astronomers have reckoned up nearly 5000.
Amongst these 5000 nebulae there is one which has received the name ofthe Milky Way, and which contains eighteen millions of stars, each ofwhich has become the centre of a solar world.
If the observer had then specially directed his attention to one of themore humble and less brilliant of these stellar bodies, a star of thefourth class, that which is arrogantly called the Sun, all the phenomenato which the formation of the Universe is to be ascribed would havebeen successively fulfilled before his eyes. In fact, he would haveperceived this sun, as yet in the gaseous state, and composed of movingmolecules, revolving round its axis in order to accomplish its work ofconcentration. This motion, faithful to the laws of mechanics, wouldhave been accelerated with the diminution of its volume; and a momentwould have arrived when the centrifugal force would have overpowered thecentripetal, which causes the molecules all to tend towards the centre.
Another phenomenon would now have passed before the observer's eye, andthe molecules situated on the plane of the equator escaping, like a stonefrom a sling of which the cord had suddenly snapped, would have formedaround the sun sundry concentric rings resembling that of Saturn. Intheir turn, again, these rings of cosmical matter, excited by a rotarymotion round the central mass, would have been broken up and decomposedinto secondary nebulosities, that is to say, into planets. Similarly hewould have observed these planets throw off one or more rings each, whichbecame the origin of the secondary bodies which we call satellites.
Thus, then, advancing from atom to molecule, from molecule to nebulousmass, from that to a principal star, from star to sun, from sun to planet,and hence to satellite, we have the whole series of transformationsundergone by the heavenly bodies during the first days of the world.
Now, of those attendant bodies which the sun maintains in their ellipticalorbits by the great law of gravitation, some few in their turn possesssatellites. Uranus has eight, Saturn eight, Jupiter four, Neptune possiblythree, and the Earth _one._ This last, one of the least important of theentire solar system, we call _the Moon_; and it is she whom the daringgenius of the Americans professed their intention of conquering.
Illustration: THE MOON'S DISC.
The moon, by her comparative proximity, and the constantly varyingappearances produced by her several phases, has always occupied aconsiderable share of the attention of the inhabitants of the earth.
From the time of Thales of Miletus, in the fifth century b.c., down tothat of Copernicus in the fifteenth and Tycho Brahe in the sixteenthcentury a.d., observations have been from time to time carried on withmore or less correctness, until in the present day the altitudes of thelunar mountains have been determined with exactitude. Galileo explainedthe phenomena of the lunar light produced during certain of her phasesby the existence of mountains, to which he assigned a mean altitude of27,000 feet. After him Hevelius, an astronomer of Dantzic, reduced thehighest elevations to 15,000 feet; but the calculations of Ricciolibrought them up again to 21,000 feet.
At the close of the eighteenth century Herschell, armed with a powerfultelescope, considerably reduced the preceding measurements. He assigneda height of 11,400 feet to the maximum elevations, and reduced the meanof the different altitudes to little more than 2400 feet. But Herschell'scalculations were in their turn corrected by the observations of Halley,Nasmyth, Bianchini, Gruithuysen, and others; but it was reserved forthe labours of Boeer and Maedler finally to solve the question. Theysucceeded in measuring 1905 different elevations, of which six exceed15,000 feet, and twenty-two exceed 14,400 feet. The highest summit of alltowers to a height of 22,606 feet above the surface of the lunar disc. Atthe same period the examination of the moon was completed. She appearedcompletely riddled with craters, and her essentially volcanic characterwas apparent at each observation. By the absence of refraction in therays of the planets occulted by her we conclude that she is absolutelydevoid of an atmosphere. The absence of air entails the absence of water.It became, therefore, manifest that the Selenites, to support life undersuch conditions, must possess a special organization of their own, mustdiffer remarkably from the inhabitants of the earth.
At length, thanks to modern art, instruments of still higher perfectionsearched the moon without intermission, not leaving a single point ofher surface unexplored; and notwithstanding that her diameter measures2150 miles, her surface equals the 1-15th part of that of our globe, andher bulk the 1-49th part of that of the terrestrial spheroid--not oneof her secrets was able to escape the eyes of the astronomers; and theseskilful men of science carried to even greater degree their prodigiousobservations.
Thus they remarked that, during full moon, the disc appeared scored incertain parts with _white_ lines; and, during the phases, with _black._On prosecuting the study of these with still greater precision, theysucceeded in obtaining an exact account of the nature of these lines.They were long and narrow furrows sunk between parallel ridges, borderinggenerally upon the edges of the craters. Their length varied betweenten and 100 miles, and their width was about 1600 yards. Astronomerscalled them chasms, but they could not get any farther. Whether thesechasms were the dried-up beds of ancient rivers or not they were unablethoroughly to ascertain.
The Americans, amongst others, hoped one day or other to determine thisgeological question. They also undertook to examine the true natureof that system of parallel ramparts discovered on the moon's surfaceby Gruithuysen, a learned professor of Munich, who considered them tobe "a system of fortifications thrown up by the Selenitic engineers."These two points, yet obscure, as well as others, no doubt, could not bedefinitively settled except by direct communication with the moon.
Regarding the degree of intensity of its light, there was nothing moreto learn on this point. It was known that it is 300,000 times weakerthan that of the sun, and that its heat has no appreciable effect uponthe thermometer. As to the phenomenon known as the "ashy light," it isexplained naturally by the effect of the transmission of the solar raysfrom the earth to the moon, which give the appearance of completeness tothe lunar disc, while it presents itself under the crescent form duringits first and last phases.
Such was the state of knowledge acquired regarding the earth's satellite,which the Gun Club undertook to perfect in all its aspects, cosmographic,geological, political, and moral.