If this were settled, it would be known if the surrounding country must fear an eruption at some period more or less distant.
The ascension was begun according to the programme suggested.

The wind was fair and steady; the sky clear; the morning clouds were disappearing under the vigorous rays of the sun.

If the interior of the Great Eyrie was not filled with smoke, the aeronaut would be able to search with his glass its entire extent.

If the vapors were rising, he, no doubt, could detect their source.
The balloon rose at once to a height of fifteen hundred feet, and there rested almost motionless for a quarter of an hour.

Evidently the east wind, which was brisk upon the Surface of the earth, did not make itself felt at that height.