sand.

"I allowed you to open the valve, because the dilatation of the gas
threatened to burst the balloon. But do not do it again."

I was stupified.

"You know the voyage from Dover to Calais made by Blanchard and
Jefferies. It was rich in incident. On the 7th of January, 1785, in a
northeast wind, their balloon was filled with gas on the Dover side;
scarcely had they risen, when an error in equilibrium compelled them to
threw out their ballast, retaining only thirty pounds. The wind drifted
them slowly along towards the shores of France. The permeability of the
tissue gradually suffered the gas to escape, and at the expiration of an
hour and a half, the voyagers perceived that they were descending.
'What is to be done?' said Jefferies.--'We have passed over only
three-fourths of the distance,' replied Blanchard 'and at a slight
elevation. By ascending we shall expose ourselves to contrary winds.
Throw out the remainder of the ballast.' The balloon regained its
ascensional force, but soon re-descended. About midway of the voyage,
the aeronauts threw out their books and tools. A quarter of an hour
afterwards, Blanchard said to Jefferies: 'The barometer?'--'It is
rising! We are lost; and yet there are the shores of France!' A great
noise was heard. 'Is the balloon rent?' asked Jefferies.--'No! the
escape of the gas has collapsed the lower part of the balloon'--'But we
are still descending. We are lost! Everything not indispensable must be
thrown overboard!' Their provisions, oars and helm were thrown out into
the sea. They were now only 100 metres in height. 'We are remounting,'
said the Doctor.--' No, it is the jerk caused by the diminution of
weight. There is not a ship in sight! Not a bark on the horizon! To the