"Another of these advantages," continued Barbican, "is that it is from the visible side alone that eclipses of the Sun can be seen. This is self-evident, the interposition of the Earth being possible only between this visible face and the Sun. Furthermore, such eclipses of the Sun would be of a far more imposing character than anything of the kind to be witnessed from our Earth. This is chiefly for two reasons: first, when we, terrestrians, see the Sun eclipsed, we notice that, the discs of the two orbs being of about the same apparent size, one cannot hide the other except for a short time; second, as the two bodies are moving in opposite directions, the total duration of the eclipse, even under the most favorable circumstances, can't last longer than 7 minutes. Whereas to a Selenite who sees the Earth eclipse the Sun, not only does the Earth's disc appear four times larger than the Sun's, but also, as his day is 14 times longer than ours, the two heavenly bodies must remain several hours in contact. Besides, notwithstanding the apparent superiority of the Earth's disc, the refracting power of the atmosphere will never allow the Sun to be eclipsed altogether. Even when completely screened by the Earth, he would form a beautiful circle around her of yellow, red, and crimson light, in which she would appear to float like a vast sphere of jet in a glowing sea of gold, rubies, sparkling carbuncles and garnets."

"It seems to me," said M'Nicholl, "that, taking everything into consideration, the invisible side has been rather shabbily treated."

"I know I should not stay there very long," said Ardan; "the desire of seeing such a splendid sight as that eclipse would be enough to bring me to the visible side as soon as possible."

"Yes, I have no doubt of that, friend Michael," pursued Barbican; "but to see the eclipse it would not be necessary to quit the dark hemisphere altogether. You are, of course, aware that in consequence of her librations, or noddings, or wobblings, the Moon presents to the eyes of the Earth a little more than the exact half of her disc. She has two motions, one on her path around the Earth, and the other a shifting around on her own axis by which she endeavors to keep the same side always turned towards our sphere. This she cannot always do, as while one motion, the latter, is strictly uniform, the other being eccentric, sometimes accelerating her and sometimes retarding, she has not time to shift herself around completely and with perfect correspondence of movement. At her perigee, for instance, she moves forward quicker than she can shift, so that we detect a portion of her western border before she has time to conceal it. Similarly, at her apogee, when her rate of motion is comparatively slow, she shifts a little too quickly for her velocity, and therefore cannot help revealing a certain portion of her eastern border. She shows altogether about 8 degrees of the dark side, about 4 at the east and 4 at the west, so that, out of her 360 degrees, about 188, in other words, a little more than 57 per cent., about 4/7 of the entire surface, becomes visible to human eyes. Consequently a Selenite could catch an occasional glimpse of our Earth, without altogether quitting the dark side."

"No matter for that!" cried Ardan; "if we ever become Selenites we must inhabit the visible side. My weak point is light, and that I must have when it can be got."

"Unless, as perhaps in this case, you might be paying too dear for it," observed M'Nicholl. "How would you like to pay for your light by the loss of the atmosphere, which, according to some philosophers, is piled away on the dark side?"

"Ah! In that case I should consider a little before committing myself," replied Ardan, "I should like to hear your opinion regarding such a notion, Barbican. Hey! Do your hear? Have astronomers any valid reasons for supposing the atmosphere to have fled to the dark side of the Moon?"

"Defer that question till some other time, Ardan," whispered M'Nicholl; "Barbican is just now thinking out something that interests him far more deeply than any empty speculation of astronomers. If you are near the window, look out through it towards the Moon. Can you see anything?"

"I can feel the window with my hand; but for all I can see, I might as well be over head and ears in a hogshead of ink."

The two friends kept up a desultory conversation, but Barbican did not hear them. One fact, in particular, troubled him, and he sought in vain to account for it. Having come so near the Moon—about 30 miles—why had not the Projectile gone all the way? Had its velocity been very great, the tendency to fall could certainly be counteracted. But the velocity being undeniably very moderate, how explain such a decided resistance to Lunar attraction? Had the Projectile come within the sphere of some strange unknown influence? Did the neighborhood of some mysterious body retain it firmly imbedded in ether? That it would never reach the Moon, was now beyond all doubt; but where was it going? Nearer to her or further off? Or was it rushing resistlessly into infinity on the wings of that pitchy night? Who could tell, know, calculate—who could even guess, amid the horror of this gloomy blackness? Questions, like these, left Barbican no rest; in vain he tried to grapple with them; he felt like a child before them, baffled and almost despairing.