e and preventing
the escape of air. After having been exposed to public inspection for
several days, it was filled three parts full of hydrogen gas, a tin
bottle was suspended from it, containing an address to whoever might
find it when it should fall, and it was let off from the Artillery
Ground, in presence of a vast assembly.

On the 11th of December, 1783, a little balloon, made of gold-beaters'
skin, was let off publicly at Turin. This was an experiment similar to
that which had been tried at Paris in September. The balloon was seen
to penetrate the clouds, then to mount still higher, and finally to
disappear entirely in five minutes fifty-four seconds from the time when
it was set free.

It was natural, after the experiments made long before with electric
paper kites, to employ the balloon in the investigation of the electric
conditions of the atmosphere. The first to use it for this purpose was
the Abbe Berthelon de Montpellier. He sent up a number of balloons, to
which he had attached pieces of metal, long and narrow, and terminating
in a cylinder of glass, or other substance suitable for the purpose
of isolation, and he obtained sufficient electricity by these means
to demonstrate the phenomena of attraction and repulsion, as well as
electric sparks.

Cavallo mentions an accident which took place in England about this
time, and which served as a warning to all who had to do with balloons
filled with hydrogen gas. A balloon thus inflated had been sent up
at Hopton, near Matlock, and was found by two men near Cheadle, in
Staffordshire. These ingenious persons carried it within doors, and
having wished to fully inflate it--half the gas having by this time
escaped--they applied a pair of bellows to its mouth. By this means they
only forced out the volume of the hydrogen gas that was left; and this
gas, coming in contact with a candle that had been placed too near,
exploded. The report was louder than that of a cannon, and so powerful
was the shock that the men were thrown down, the glass blown out of the
windows, and the house otherwise damaged. The men suffered severely,
their hair, beards, and eyebrows being completely burnt away, and their
faces severely scorched.

At Grenoble, in Dauphine, De Baron let off a balloon on the 13th of
January, 1784. It rose, and at first took a northern direction;
but, having encountered a current of air, it was carried away in a
south-easterly direction, and after flying a di