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 Abbé 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 Dauphiné, De Baron let off a balloon
