But it was of no use to talk of paper: since there was not enough; and Karl had given over thinking of a balloon: because there was nothing within reach likely to serve for its construction.
He knew that that great sphere would require to be air-proof.

He had thought of the skins of animals; but such of these as might have been obtained in sufficient quantity, were entirely too thick and heavy to make the covering of a balloon.

The hemp, of which there _was_ an abundance, might be woven into a cloth, and then coated over by gum obtained from some tree; for in the valley were several species of gum-exuding trees.

But the question was, could they manufacture a cloth out of hemp that would be light enough when thus coated over?
It was very doubtful whether they could--at all events they would have to practise the weaving trade for a long time, before they should arrive at a sufficient expertness to accomplish such a feat.

The plan was too unpromising to be seriously entertained; and Karl had dismissed it, along with the whole subject of the balloon.
That had been previous to the experiment of the kite, and its unfortunate ending.