The precious instruments by which these observations were to be made were prepared, and in some cases actually fabricated and graduated, by the hands of M. Regnault himself.
To provide the balloon and its appendages, recourse was had to some of those persons who have followed the fabrication of balloons as a sort of trade, for the purposes of exhibition.
In this part of their enterprise the voyagers were not so fortunate, as we shall presently see, and still less so in having taken the resolution to ascend alone, unaccompanied by a practiced æronaut. It is probable that if they had selected a person, such as Mr. Green, for example, who had already made frequent ascents for the mere purpose of exhibition, and who had become familiar with the practical management of the machine, a much more favorable result would have ensued. As it was, the two voyagers ascended for the first time, and placed themselves in a position like that of a natural philosopher, who, without previous practice, should undertake to drive a locomotive, with its train on a railway at fifty miles an hour, rejecting the humble but indispensable aid of an experienced engine-driver.
The necessary preparations having been made, and the programme and the instruments prepared, it was resolved to make the ascent from the garden behind the Observatory at Paris, a plateau of some elevation, and free from buildings and other obstacles, at day-break of Saturday, the 29th June. At midnight the balloon was brought to the spot, but the inflation was not completed until nearly 10 o’clock, A.M.
It has since been proved that the balloon was old and worn, and that it ought not to have been supplied for such an occasion.
It was obviously patched, and it is now known that two seamstresses were employed during the preceding day in mending it, and some stitching even was found necessary after it had arrived at the Observatory.
The net-work which included and supported the car was new, and not originally made with a view to the balloon it inclosed, the consequences of which will be presently seen.
The night, between Friday and Saturday, was one of continual rain, and the balloon and its netting became thoroughly saturated with moisture. By the time the inflation had been completed, it became evident that the net-work was too small; but in the anxiety to carry into effect the project, the consequences of this were most unaccountably overlooked. We say unaccountably, because it is extremely difficult to conceive how experimental philosophers and practiced observers, like MM. Arago and Regnault, to say nothing of numerous subordinate scientific agents who were present, did not anticipate what must have ensued in the upper regions of the air. Nevertheless, such was the fact.
On the morning of Saturday, the instruments being duly deposited in the car, the two enterprising voyagers placed themselves in it, and the balloon, which previously had been held down by the strength of twenty men, was liberated, and left to plunge into the ocean of air, at twenty-seven minutes after ten o’clock.
The weather, as we have already stated, was unfavorable, the sky being charged with clouds. As it was the purpose of this project to examine much higher regions of the atmosphere than those which it had been customary for aeronautic exhibitors to rise to, the arrangements of ballast and inflation which were adopted, were such as to cause the ascent to be infinitely more rapid than in the case of public exhibitions; in short, the balloon darted upward with the speed of an arrow, and in two minutes from the moment it was liberated, that is to say, at twenty-nine minutes past ten, plunged into the clouds, and was withdrawn from the anxious view of the distinguished persons assembled in the garden of the Observatory.