--"The comets were all used up long ago--" interrupted M'Nicholl. --"Yes," went on Barbican, as serenely as a judge, "comets, they said, had fallen on the surface in meteoric showers and crushed in the crater cavities; comets had dried up the water; comets had whisked off the atmosphere; comets had done everything. All pure assumption! In your case, however, friend Michael, no comet whatever is necessary. The shock that gave rise to your great 'star' may have come from the interior rather than the exterior. A violent contraction of the lunar crust in the process of cooling may have given birth to your gigantic 'star' formation." "I accept the amendment," said Ardan, now in the best of humor and looking triumphantly at M'Nicholl. "An English scientist," continued Barbican, "Nasmyth by name, is decidedly of your opinion, especially ever since a little experiment of his own has confirmed him in it. He filled a glass globe with water, hermetically sealed it, and then plunged it into a hot bath. The enclosed water, expanding at a greater rate than the glass, burst the latter, but, in doing so, it made a vast number of cracks all diverging in every direction from the focus of disruption. Something like this he conceives to have taken place around _Tycho_. As the crust cooled, it cracked. The lava from the interior, oozing out, spread itself on both sides of the cracks. This certainly explains pretty satisfactorily why those flat glistening streaks are of much greater width than the fissures through which the lava had at first made its way to the surface." "Well done for an Englishman!" cried Ardan in great spirits. "He's no Englishman," said M'Nicholl, glad to have an opportunity of coming off with some credit. "He is the famous Scotch engineer who invented the steam hammer, the steam ram, and discovered the 'willow leaves' in the Sun's disc." "Better and better," said Ardan--"but, powers of Vulcan! What makes it so hot? I'm actually roasting!" This observation was hardly necessary to make his companions conscious that by this time they felt extremely uncomfortable. The heat had become quite oppressive. Between the natural caloric of the Sun and the reflected caloric of the Moon, the Projectile was fast turning into a regular bake oven. This transition from intense cold to intense heat was already about quite as much as they could bear. "What shall we do, Barbican?" asked Ardan, seeing that for some time no one else appeared inclined to say a word.