CHAPTER XVIII.
PUZZLING QUESTIONS.
It was not until the Projectile had passed a little beyond _Tycho's_ immense concavity that Barbican and his friends had a good opportunity for observing the brilliant streaks sent so wonderfully flying in all directions from this celebrated mountain as a common centre.

They examined them for some time with the closest attention.
What could be the nature of this radiating aureola?
By what geological phenomena could this blazing coma have been possibly produced?
Such questions were the most natural things in the world for Barbican and his companions to propound to themselves, as indeed they have been to every astronomer from the beginning of time, and probably will be to the end.
What _did_ they see?
What you can see, what anybody can see on a clear night when the Moon is full--only our friends had all the advantages of a closer view.

From _Tycho_, as a focus, radiated in all directions, as from the head of a peeled orange, more than a hundred luminous streaks or channels, edges raised, middle depressed--or perhaps _vice versa_, owing to an optical illusion--some at least twelve miles wide, some fully thirty.

In certain directions they ran for a distance of at least six hundred miles, and seemed--especially towards the west, northwest, and north--to cover half the southern hemisphere.

One of these flashes extended as far as _Neander_ on the 40th meridian; another, curving around so as to furrow the _Mare Nectaris_, came to an end on the chain of the _Pyrenees_, after a course of perhaps a little more than seven hundred miles.