"Seven hundred and seventy meters (about 2,900 feet), as indicated on the barometer."
"Could you see the earth?" asked Alfred.
"No, indeed; the rain was pouring down; it was splashing over us and all about us, and I signalled to go up again, and we soon entered the clouds; but during all this time the needle of the compass kept spinning, so that we knew nothing of the direction we were traveling."
"But couldn't you tell which way the wind was blowing?" asked Ralph.
"No; we were moving with the great air current, sometimes sailing with it, and at other times against it, but with nothing below to indicate the direction. We could not possibly say whether we were going north or south."
"I think if I should be in the air and couldn't see the earth I would know a way to tell which way the storm was moving," said Ralph.
"How?" asked the lieutenant, as he leaned forward.
"Why, the rain would come down at an angle, if the wind should be blowing, wouldn't it?" replied Alfred.
"Quite true, that would be the case on the earth; but it would not be so up where the raindrops are being formed; there the little particles of water move along with the wind stream; but that is not all; when you are in a machine in a great wind movement, the ship must move through the wind in one direction or the other at all times so as to keep aloft, hence, whether you are going with or against the wind, the rain drops appear to be coming down at an angle, and this, in itself would be sufficient to deceive you, or, at any rate prevent you from determining the direction in which you happened to be sailing."
"How did you get down?" asked Alfred.