of eleven, when the observers finding the
barometer cease the upward motion, and finding that the machine
oscillated round a position of equilibrium by noticing the bearing of
the sun, they found the epoch favorable for another series of
observations. The barometer there indicated that the balloon had
attained the enormous height of 19,700 feet. The moisture which had
invested the thermometer had frozen upon it, and obstructed, for the
moment, observations with it. It was while M. Barral was occupied in
wiping the icicles from it, that, turning his eye upward, he beheld what
would have been sufficient to have made the stoutest heart quail with
fear.

To explain the catastrophe which at this moment, and at nearly 20,000
feet above the surface of the earth, and about a mile above the highest
strata of the clouds, menaced the voyagers, we must recur to what we
have already stated in reference to the balloon and the net-work. As it
was intended to ascend to an unusual altitude, it was of course known,
that in consequence of the highly rarefied state of the atmosphere, and
its very much diminished pressure, the gas contained in the balloon
would have a great tendency to distend, and, consequently, space must be
allowed for the play of this effect. The balloon, therefore, at
starting, was not nearly filled with gas, and yet, as we have explained
it, very nearly filled the net-work which inclosed it. Is it not strange
that some among the scientific men present did not foresee, that when it
would ascend into a highly rarefied atmosphere, it would necessarily
distend itself to such a magnitude, that the netting would be utterly
insufficient to contain it? Such effect, so strangely unforeseen, now
disclosed itself practically realized to the astonished and terrified
eyes of M. Barral.

The balloon, in fact, had so swelled as not only completely to fill the
netting which covered it, but to force its way, in a frightful manner,
through the hoop under it, from which the car, and the voyagers were
suspended.

In short, the inflated silk protruding downward through the hoop, now
nearly touched the heads of the voyagers. In this emergency the remedy
was sufficiently obvious.

The valve must be opened, and the balloon breathed, so as to relieve it
from the over-inflation. Now, it is well known, that the valve in this
machine is placed in a sort of sleeve, of a length more or less
considerable, connected with the lower part of the b