movement suddenly stopped produces heat.
This theory makes it supposed that the sun is constantly fed by an
incessant fall of bodies upon its surface. It has been calculated--"

"Now I shall be crushed," murmured Michel, "for figures are coming."

"It has been calculated," continued Barbicane imperturbably, "that the
shock of each asteroid upon the sun must produce heat equal to that of
4,000 masses of coal of equal volume."

"And what is the heat of the sun?" asked Michel.

"It is equal to that which would be produced by a stratum of coal
surrounding the sun to a depth of twenty-seven kilometres."

"And that heat--"

"Could boil 2,900,000,000 of cubic myriametres of water an hour." (A
myriametre is equal to rather more than 6.2138 miles, or 6 miles 1
furlong 28 poles.)

"And we are not roasted by it?" cried Michel.

"No," answered Barbicane, "because the terrestrial atmosphere absorbs
four-tenths of the solar heat. Besides, the quantity of heat intercepted
by the earth is only two thousand millionth of the total."

"I see that all is for the best," replied Michel, "and that our
atmosphere is a useful invention, for it not only allows us to breathe,
but actually prevents us roasting."

"Yes," said Nicholl, "but, unfortunately, it will not be the same on the
moon."

"Bah!" said Michel, always confident. "If there are any inhabitants they
breathe. If there are no longer any they will surely have left enough
oxygen for three people, if only at the bottom of those ravines where it
will have accumulated by reason of its weight! Well, we shall not climb
the mountains! That is all."

And Michel, getting up, went to look at the lunar disc, which was
shining with intolerable brilliancy.

"Faith!" said he, "it must be hot up there."

"Without reckoning," answered Nicholl, "that daylight lasts 360 hours."

"And by way of compensation night has the same duration," said
Barbicane, "and as heat is restored by radiation, their temperature must
be that of planetary space."

"A fine country truly!" said Nicholl.

"Never mind! I should like to be there already! It will be comical to
have the earth for a moon, to see it rise on the horizon, to recognise
the configuration of its continents, to say to oneself, 'There's America
and there's Europe;' then to follow it till it is lost in the rays of
the sun! By-the-bye, Barbicane, have the Selenites any eclipses?"

"Yes, eclipses of the sun," answered Barbicane, "when the