These streaks, the travellers thought, could be traced further north than in any other direction: they fancied they could detect them even in the _Mare Imbrium_, but this of course might be owing to the point from which they made their observations.

At one o'clock in the morning, the Projectile, flying through space, was exactly over this magnificent mountain.
In spite of the brilliant sunlight that was blazing around them, the travellers could easily recognize the peculiar features of _Copernicus_.
It belongs to those ring mountains of the first class called Circuses.
Like _Kepler_ and _Aristarchus_, who rule over _Oceanus Procellarum_, _Copernicus_, when viewed through our telescopes, sometimes glistens so brightly through the ashy light of the Moon that it has been frequently taken for a volcano in full activity.

Whatever it may have been once, however, it is certainly nothing more now than, like all the other mountains on the visible side of the Moon, an extinct volcano, only with a crater of such exceeding grandeur and sublimity as to throw utterly into the shade everything like it on our Earth.

The crater of Etna is at most little more than a mile across.

The crater of _Copernicus_ has a diameter of at least 50 miles.