So saying, he jumped up and began to gaze with considerable interest on
the lunar disc, which just then was glittering with dazzling brightness.

"By Jove!" he exclaimed at length; "it must be pretty hot up there!"

"I should think so," observed the Captain; "especially when you remember
that the day up there lasts 360 hours!"

"Yes," observed Barbican, "but remember on the other hand that the
nights are just as long, and, as the heat escapes by radiation, the mean
temperature cannot be much greater than that of interplanetary space."

"A high old place for living in!" cried Ardan. "No matter! I wish we
were there now! Wouldn't it be jolly, dear boys, to have old Mother
Earth for our Moon, to see her always on our sky, never rising, never
setting, never undergoing any change except from New Earth to Last
Quarter! Would not it be fun to trace the shape of our great Oceans and
Continents, and to say: 'there is the Mediterranean! there is China!
there is the gulf of Mexico! there is the white line of the Rocky
Mountains where old Marston is watching for us with his big telescope!'
Then we should see every line, and brightness, and shadow fade away by
degrees, as she came nearer and nearer to the Sun, until at last she sat
completely lost in his dazzling rays! But--by the way--Barbican, are
there any eclipses in the Moon?"

"O yes; solar eclipses" replied Barbican, "must always occur whenever
the centres of the three heavenly bodies are in the same line, the Earth
occupying the middle place. However, such eclipses must always be
annular, as the Earth, projected like a screen on the solar disc, allows