to
determine the point, by making a complete exploration of the valley. It
may be that something else might turn up which would answer the purpose
equally as well. There is a birch-tree indigenous to the Himalaya
mountains, found both in Nepaul and Thibet. Its bark can be stripped
off in broad flakes and layers, to the number of eight or ten--each
almost as thin as common paper, and suitable for many purposes to which
paper is usually applied."

"Do you think it would do for a kite?" inquired Caspar, without waiting
for Karl to finish his explanation.

"I am sure of it," replied the botanist. "It would serve even better
than the daphne paper; and had I believed there was a chance of finding
it here, I should have preferred it to that. But I do not think we
shall find it. I have observed no species of birch; and I know that
this one, like most of the _Betulaceae_, affects a much colder climate
than there is in this valley. Likely enough, it grows on the mountains
above; but there it is out of our reach. Could we reach it there, we
should not need to be robbing it of its manifold envelope. But let us
not despair," added Karl, endeavouring to appear cheerful; "perhaps it
may be found growing down here; or, if not, we may still find another
grove of the daphne trees. Let us proceed on and search!"

Karl was far from being sanguine in either conjecture; and it was as
well for him that he was not: for after a minute and careful exploration
of the valley--which occupied nearly three whole days--neither the
wished-for birch, nor the desired daphne trees--nor any other material
out of which a kite might be manufactured--rewarded their search.

It was of no use, therefore, to think any longer of a kite; and the
subject was at length dismissed from their minds.

CHAPTER FORTY NINE.

AEROSTATICS.

It is scarce possible to talk of a paper kite, without thinking of that
other and greater aerostatic contrivance--a balloon.

Karl had thought of it, long before this time; and so had Caspar, just
as long: for the kite had suggested it simultaneously to the minds of
both.

It may be asked why they had not entertained the thought, and
endeavoured to carry it into practical effect: since a balloon would
have been far more likely to have delivered them out of their "mountain
prison" than a paper kite?

But they _had_ entertained the thought--at least, Karl had done so--and
examined it in all its bearings. Caspar h