The disc appeared through the telescopes at a distance of two and a half leagues. If an aeronaut were taken up that distance from the earth, what would he distinguish upon its surface? No one can tell, as the highest ascensions have not exceeded 8,000 metres.
The following, however, is an exact description of what Barbicane and his companions saw from that height:—
Large patches of different colours appeared on the disc. Selenographers do not agree about their nature. They are quite distinct from each other. Julius Schmidt is of opinion that if the terrestrial oceans were dried up, a Selenite observer could only tell the difference between the terrestrial oceans and continental plains by patches of colour as distinctly varied as those which a terrestrial observer sees upon the moon. According to him, the colour common to the vast plains, known under the name of “seas,” is dark grey, intermingled with green and brown. Some of the large craters are coloured in the same way.
Barbicane knew this opinion of the German selenographer; it is shared by Messrs. Boeer and Moedler. He noticed that they were right, whilst certain astronomers, who only allow grey colouring on the surface of the moon, are wrong. In certain places the green colour was very vivid; according to Julius Schmidt, it is so in the Seas of Serenity and Humours. Barbicane likewise remarked the wide craters with no interior cones, which are of a bluish colour, analogous to that of fresh-polished sheets of steel. These colours really belonged to the lunar disc, and did not result, as certain astronomers think, either from some imperfection in the object-glasses of the telescopes or the interposition of the terrestrial atmosphere. Barbicane had no longer any doubt about it. He was looking at it through the void, and could not commit any optical error. He considered that the existence of this different colouring was proved to science. Now were the green shades owing to tropical vegetation, kept up by a low and dense atmosphere? He could not yet be certain.
Farther on he noticed a reddish tinge, quite sufficiently distinct. A similar colour had already been observed upon the bottom of an isolated enclosure, known under the name of the Lichtenberg Amphitheatre, which is situated near the Hercynian Mountains, on the border of the moon. But he could not make out its nature.
He was not more fortunate about another peculiarity of the disc, for he could not find out its cause. The peculiarity was the following one:—
Michel Ardan was watching near the president when he remarked some long white lines brilliantly lighted up by the direct rays of the sun. It was a succession of luminous furrows, very different from the radiation that Copernicus had presented. They ran in parallel lines.
Michel, with his usual readiness, exclaimed—
“Why, there are cultivated fields!”
“Cultivated fields!” repeated Nicholl, shrugging his shoulders.
“Ploughed fields, at all events,” replied Michel Ardan. “But what ploughmen these Selenites must be, and what gigantic oxen they must harness to their ploughs, to make such furrows!”
“They are not furrows, they are crevices!”
“Crevices let them be,” answered Michel with docility. “Only what do you mean by crevices in the world of science?” Barbicane soon told his companions all he knew about lunar crevices. He knew that they were furrows observed upon all the non-mountainous parts of the lunar disc; that these furrows, generally isolated, were from four to five leagues only; that their width varies from 1,000 to 1,500 metres, and their edges are rigorously parallel. But he knew nothing more about their formation or their nature.
Barbicane watched these furrows through his telescope very attentively. He noticed that their banks were exceedingly steep. They were long parallel ramparts; with a little imagination they might be taken for long lines of fortifications raised by Selenite engineers.
Some of these furrows were as straight as if they had been cut by line, others were slightly curved through with edges still parallel. Some crossed each other. Some crossed craters. Some furrowed the circular cavities, such as Posidonius or Petavius. Some crossed the seas, notably the Sea of Serenity.
These accidents of Nature had naturally exercised the imagination of terrestrial astronomers. The earliest observations did not discover these furrows. Neither Hevelius, Cassini, La Hire, nor Herschel seems to have known them. It was Schroeter who in 1789 first attracted the attention of savants to them. Others followed who studied them, such as Pastorff, Gruithuysen, Boeer, and Moedler. At present there are seventy-six; but though they have been counted, their nature has not yet been determined. They are not fortifications certainly, anymore than they are beds of dried-up rivers, for water so light on the surface of the moon could not have dug such ditches, and there furrows often cross craters at a great elevation.
It must, however, be acknowledged that Michel Ardan had an idea, and that, without knowing it, he shared it with Julius Schmidt.
“Why,” said he, “may not these inexplicable appearances be simply phenomena of vegetation?”
“In what way do you mean?” asked Barbicane.
“Now do not be angry, worthy president,” answered Michel, “but may not these black lines be regular rows of trees?”
“Do you want to find some vegetation?” said Barbicane.
“I want to explain what you scientific men do not explain! My hypothesis will at least explain why these furrows disappear, or seem to disappear, at regular epochs.”
“Why should they?”
“Because trees might become invisible when they lose their leaves, and visible when they grow again.”
“Your explanation is ingenious, old fellow,” answered Barbicane, “but it cannot be admitted.”
“Why?”
“Because it cannot be said to be any season on the surface of the moon, and, consequently, the phenomena of
