at the time overlooked.

On August 25, 1783, the balloon was liberated on the Champ de
Mars before an enormous concourse, and in less than two minutes
had reached an elevation of half a mile, when it was temporarily
lost in cloud, through which, however, it penetrated, climbing
into yet higher cloud, when, disappearing from sight, it
presently burst and descended to earth after remaining in the
air some three-quarters of an hour.

The bursting of this little craft taught the future balloonist
his first great lesson, namely, that on leaving earth he must
open the neck of his balloon; and the reason of this is obvious.
While yet on earth the imprisoned gas of a properly filled
balloon distends the silk by virtue of its expansive force, and
in spite of the enormous outside pressure which the weight of
air exerts upon it. Then, as the balloon rises high in the air
and the outside pressure grows less, the struggling gas within,
if allowed no vent, stretches the balloon more and more until
the slender fabric bursts under the strain.

At the risk of being tedious, we have dwelt at some length on
the initial experiments which in less than a single year had led
to the discovery and development of two distinct methods--still
employed and in competition with each other--of dismissing
balloons into the heavens. We are now prepared to enter fully
into the romantic history of our subject which from this point
rapidly unfolds itself.

Some eleven months only after the two Montgolfiers were