There is record of an attempt of some sort that was made to revive the French military ballooning school in the African campaign of 1830, but it was barren of results. Again, it has been stated that the Austrians used balloons for reconnaissance, before Venice in 1849, and yet again the same thing is related of the Russians at the time of the siege of Sebastopol, though Kinglake does not mention the circumstance. In 1846 Wise drew up and laid before the American War Office an elaborate scheme for the reduction of Vera Cruz. This will be discussed in its due place, though it will be doubtless considered as chimerical.

On the other hand, eminently practical were the experiments co-ordinated and begun to be put to an actual test by Mr. Coxwell, who, before he could duly impress his project upon the military authorities, had to make preliminary trials in private ventures. The earliest of these was at the Surrey Zoological Gardens in the autumn of 1854, and it will be granted that much ingenuity and originality were displayed when it is considered that at that date neither wireless telegraphy, electric flashlight, nor even Morse Code signalling was in vogue. According to his announcement, the spectators were to regard his balloon, captive or free, as floating at a certain altitude over a beleaguered fortress, the authorities in communication with it having the key of the signals and seeking to obtain through these means information as to the approach of an enemy. It was to be supposed that, by the aid of glasses, a vast distance around could be subjected to careful scrutiny, and a constant communication kept up with the authorities in the fortress. Further, the flags or other signals were supposed preconcerted and unknown to the enemy, being formed by variations of shape and colour. Pigeons were also despatched from a considerable height to test their efficiency under novel conditions. The public press commented favourably on the performance and result of this initial experiment.