From the Earth to the Moon by Jules Verne Read Free Book Online Page A

Aristarchus of Samos gave the correct explanation of its phases. Cleomedes taught that it shone with reflected light. The Chaldean Berosus discovered that the duration of its rotation was equal to that of its revolution, and in this way he was able to explain the fact that it always presents the same side to the earth. Finally Hipparchus, nearly two centuries before Christ, recognized certain irregularities in its apparent motions.
    These various observations were later confirmed, and were beneficial to later astronomers. Ptolemy in the second century, and the Arab Abul Wefa in the tenth, completed Hipparchus’ discoveries concerning the irregularities of the moon’s motion as it describes the undulating line of its orbit under the influence of the sun. Then Copernicus in the fifteenth century, and Tycho Brahe in the sixteenth, completely described the solar system and the part played by the moon in the assemblage of heavenly bodies.
    At that time its motions were determined more or less accurately, but little was known of its physical constitution. Then Galileo explained the light phenomena that occurred at certain phases of the moon by the existence of mountains on its surface. He placed their average height at 27,000 feet.
    Hevelius, a Danzig astronomer, later lowered the greatest heights to 15,600 feet, but his colleague Riccioli brought them up to 42,000.
    At the end of the eighteenth century, Herschel, armed with a powerful telescope, drastically reduced the previous measurements. He gave 11,400 feet to the highest mountains and brought the average to only 2,400. But he, too, was mistaken. It took the observations of Schroeter, Louville, Halley, Nasmyth, Bianchini, Pastorf, Lohrmann, and Gruithuysen, and especially the patient studies of Beer and Moedeler, to settle the matter definitively. Thanks to these scientists, the height of the mountains of the moon is now perfectly known. Beer and Moedeler measured 1,905 mountains, of which six are greater than 15,600 in height, and twenty-two are higher than 14,400 feet. * The tallest peak rises 22,806 feet above the surface of the moon.
    At the same time, visual exploration of the moon was being completed. It was seen to be riddled with craters, and its essentially volcanic nature became increasingly apparent with each observation. From the absence of refraction in the light from planets occulted by it, the conclusion was drawn that it must have almost no atmosphere. This lack of atmosphere implied a lack of water. It was therefore obvious that, to live under such conditions, the lunar inhabitants must have a special constitution and be radically different from the inhabitants of the earth.
    Finally, thanks to new methods, improved instruments constantly scanned the moon, leaving no part of its visible surface unexplored, even though its diameter is 2,150 miles, about a quarter of the earth’s, its area is one-thirteenth that of the earth, and its volume one-forty-ninth. None of these secrets could escape the eyes of theastronomers, and the skilled scientists carried their prodigious observations still further.
    Thus they noticed that when the moon was full there were white lines across it, and black lines during its phases. They studied these lines with greater precision and succeeded in determining their nature. They were long, narrow furrows with parallel edges, usually ending in the vicinity of a crater, about fifty feet wide and anywhere from ten to a hundred miles long. The astronomers called them “grooves,” but giving them that name was all they could do. As for the question of whether or not these grooves were the dry beds of former streams, they could not answer it satisfactorily. The Americans hoped to be able to solve this geological puzzle some day. They also intended to reconnoiter that series of parallel ramparts discovered on the surface of the moon by Gruithuysen, a learned Munich professor, who regarded them as a system of fortifications erected by