To these various characters Coutelle added a certain number of mechanics, whose services were indispensable. His first lieutenant, Delaunay, was formerly a master mason, and proved useful in the construction of furnaces, for it required no less than 12,000 bricks to build the furnace for the manufacture of gas.
The process of inflation lasted from thirty-six to forty hours. I may here call attention to the decided improvement which appears to have been made in the generation and storage of hydrogen gas for the English balloon force. Compressed gas is now supplied at Chatham in metal receivers, which can be sent abroad, as it was to Suakim. This plan has its advantages and difficulties. It must be very expensive, and the weight of the cylinders is an objection where every ounce of impedimenta has to be sometimes thought of.
The French balloons were made of silk, and so efficiently varnished that they retained the gas for two to three months.
In this important element we are behind the French, as mere calico was the first fabric used in the construction of the Woolwich balloons, and though professional aëronauts for public ascents may sometimes resort to cotton balloons, still for military objects, silk, although the most costly, is, I should say, the lightest, strongest, tightest, and best.
We must allow for considerable exaggeration in the much vaunted holding powers of the original French balloons, and, for the matter of that, for the latest productions as well, both in England and on the continent. I must include the Channel balloonists.
It is all very well to talk and write about such a volatile substance as hydrogen, or even coal gas, remaining good for three months or a month. Aëronauts deny it.
Will a volume of the lightest known fluid be fit for much after being a fortnight or even a week in either a silk, skin, or so-called india-rubber envelopes.
Until ballooning is divested of much that is absurd, untruthful, and misleading, real progress will be slow.
The balloon “Entreprenant” which was sent to the army of the north was only twenty-seven feet in diameter, and its lifting power was 500 pounds. It was held fast by two ropes which were attached to some extra network at the equator; but considering that in those days the network did not cover much more than half of the balloon, we should not fail to notice that at present balloons are enveloped in much more extensive and elongated nets which protect the lower hemisphere, and prevent the escape of the balloon unless the network gives way. It is generally made of thicker cord below, so that this danger is more guarded against than it was in the year 1794.
The army of the Meuse-Sambre had the “Céleste” balloon, while the “Hercule” and “Intrepide” were sent to the Rhine-Moselle.