“They cannot see down to our habitations, for two reasons. In the first place, although the craters connect with the vast labyrinth of passages and chambers below, with few exceptions they bend and subdivide into numerous dividing branches long before they get down to a habitable level. In the second place there are perpetual clouds standing in all those passages, that lead to the surface of the hump, at various elevations of from two or three to eight or ten miles above the sea level. Of course it is not possible to see down through these—nor up through them either—except when they are cleared away for a special purpose, as is done sometimes for the benefit of our astronomers.”
“They sometimes look out through these craters then, do they? How do they get rid of the clouds?”
“I will describe one of the craters used by the astronomers for an observatory. It is the shape of a funnel with a diameter at the surface of the hump of twenty-five miles. From there it tapers rapidly inwards till at a distance of about 29 miles below the surface, it has narrowed down to a mile in diameter. This is the entrance, down to what was originally a vast dome shaped chamber. This chamber is now filled to the roof on one side, by material poured down through the funnel, while on the other side the material consisting of volcanic ashes, scoria, rocks etc., slopes down for three miles, the over-arching dome finally closing down to it leaving only a few narrow passages through into other chambers. Well up on this slope and nearly under the center of the great funnel, our astronomers established their observatory. This is for the special purpose of examining the earth, which is always in sight from this point, and as it rolls itself over every twenty-four hours, without apparently moving out of its tracks, it is seemingly on exhibition for our sole benefit. As we revolve around it every month we are enabled to see both poles alternately, while the whole of the equatorial parts can be seen every twenty-four hours.
“We are thus enabled to make far more complete and perfect maps of the earth, than you have yourselves. We have powerful telescopes. The one at the funnel observatory I am telling you of, can bring the earth within forty miles.”
“If it brought it eleven miles further it would stop up the funnel and become invisible, wouldn’t it?” said I.
His eyes expressed a slight gleam of humor, which I fancied was tinged by a shade of compassion, as he recognized this for a joke, and then he went on:
“As to the clouds—they are cleared away whenever we wish, by means of artificial thunder storms. Metallic conductors have been put in place up the sides of the lofty chambers, and at the proper heights are fixed with their poles pointing across the space, the positive on one side and the negative on the opposite. Heavy electric discharges are then made, the spark which is often one-fourth of a mile long traversing the cloud and speedily condensing it into rain. The observatory, I have spoken of, is too high to be often affected by clouds, but when the funnel is hazy, it can soon be cleared out. There are several observatories on this side of the moon situated like this one, and their chief business is the examination of the earth, which is our most interesting celestial object, and which can never be seen from the external continent, except at its extreme east and west ends, from which position it is seen low down on the horizon.”
“It must be extremely handy,” said I, “to be able to produce a shower whenever you wish. The formation of these clouds however presupposes great evaporation.”
“Yes, evaporation takes, place from the numerous sheets of sea water in the various chambers, the aggregate of which is estimated at about 120,000 square miles. There is more or less of this sea water in almost every one of the sea-level chambers. Besides the evaporation from these bodies of water, more or less evaporation occurs from every one of the industries in which water is used, and so the aggregate is very considerable. But it is always nearly uniform in quantity, in the interior continent. As the suspended moisture comes into contact with the upper walls and roofs of the lofty chambers, it is being constantly condensed, and the fresh water thus formed trickles down the walls and slopes in drops, rills and brooks, and finds its way through the ground and porous rocks. Many underground streams are formed that find their way into the high-level chambers, which are thus supplied with pure water. The inhabitants of others have supplied themselves by tunnelling through into the upper parts of lofty chambers, that have their floors at the sea-level, and thus they tap the clouds themselves.”
“Our astronomers tell us that some of the Lunar craters are 60 or 80 miles in diameter or even more, which indicates that an enormously greater amount of volcanic action has taken place on the moon than on the earth. How is that?”