“Oh, dear!” murmured Michel, “the figures are coming.” “They have even calculated,” continued the imperturbable Barbicane, “that the shock of each meteor on the sun ought to produce a heat equal to that of 4,000 masses of coal of an equal bulk.” “And what is the solar heat?” asked Michel. “It is equal to that produced by the combustion of a stratum of coal surrounding the sun to a depth of forty-seven miles.” “And that heat—” “Would be able to boil two billions nine hundred millions of cubic myriameters[2] of water.” [2] The myriameter is equal to rather more than 10,936 cubic yards English. “And it does not roast us!” exclaimed Michel. “No,” replied Barbicane, “because the terrestrial atmosphere absorbs four-tenths of the solar heat; besides, the quantity of heat intercepted by the earth is but a billionth part of the entire radiation.” “I see that all is for the best,” said Michel, “and that this atmosphere is a useful invention; for it not only allows us to breathe, but it prevents us from roasting.” “Yes!” said Nicholl, “unfortunately, it will not be the same in the moon.” “Bah!” said Michel, always hopeful. “If there are inhabitants, they must breathe. If there are no longer any, they must have left enough oxygen for three people, if only at the bottom of ravines, where its own weight will cause it to accumulate, and we will not climb the mountains; that is all.” And Michel, rising, went to look at the lunar disc, which shone with intolerable brilliancy. “By Jove!” said he, “it must be hot up there!” “Without considering,” replied Nicholl, “that the day lasts 360 hours!” “And to compensate that,” said Barbicane, “the nights have the same length; and as heat is restored by radiation, their temperature can only be that of the planetary space.” “A pretty country, that!” exclaimed Michel. “Never mind! I wish I was there! Ah! my dear comrades, it will be rather curious to have the earth for our moon, to see it rise on the horizon, to recognize the shape of its continents, and to say to oneself, ‘There is America, there is Europe;’ then to follow it when it is about to lose itself in the sun’s rays! By the bye, Barbicane, have the Selenites eclipses?” “Yes, eclipses of the sun,” replied Barbicane, “when the centers of the three orbs are on a line, the earth being in the middle. But they are only partial, during which the earth, cast like a screen upon the solar disc, allows the greater portion to be seen.” “And why,” asked Nicholl, “is there no total eclipse? Does not the cone of the shadow cast by the earth extend beyond the moon?” “Yes, if we do not take into consideration the refraction produced by the terrestrial atmosphere. No, if we take that refraction into consideration. Thus let <lower case delta> be the horizontal parallel, and _p_ the apparent semidiameter—” “Oh!” said Michel. “Do speak plainly, you man of algebra!”