his two assistants to construct a balloon of taffeta, twelve feet in diameter, covered with india-rubber, and to inflate it with hydrogen.
The thing thus arranged, a subscription was opened. The projected experiment having been talked of all over Paris, every one was struck with the idea, and subscriptions poured in. Even the most illustrious names are to be found in the list, which may be called the first national subscription in France. Nothing had been written of the forthcoming event in any public paper, yet all Paris seemed to flock to contribute to the curious experiment.
The inflation with hydrogen was effected in a very curious manner. As much as 1,125 lbs. of iron and 560 lbs. of sulphuric acid were found necessary to inflate a balloon which had scarcely a lifting power of 22 lbs., and the process of filling took no less than four hours. At length, however, at the end of the fourth hour, the balloon, composed of strips of silk, coated with varnish, floated, two-thirds full, from the workshop of the brothers Robert.
On the morning of the 26th of August, the day before the ascent was to be made, the balloon was visited at daybreak, and found to be in a promising state. At two o'clock on the following morning its constructors began to make preparations to transport it to the Champ de Mars, from which place it was to be let loose. Skilled workmen were employed in its removal, and every precaution was taken that the gas with which it was charged should not be allowed to escape. In the meantime the excitement of the people about this wonderful structure was rising to the highest pitch. The wagon on which it was placed for removal was surrounded on all sides by eager multitudes,
