They went away even before the battle of Borodino and still more rapidly after it, despite Rostopchin's calls to defend Moscow or the announcement of his intention to take the wonder-working icon of the Iberian Mother of God and go to fight, or of the balloons that were to destroy the French, and despite all the nonsense Rostopchin wrote in his broadsheets.
In the first group we have to notice the use of iron or zinc and dilute sulphuric acid for the manufacture of hydrogen, which may be used directly, as for inflating balloons or for purposes of combustion, or in the nascent condition, for reduction purposes, as generally is the case in organic chemistry (see Aniline).
A structure is supported either by resting on the solid crust of the earth, as buildings do, or by floating in a fluid, as ships do in water and balloons in air.
At great heights free balloons seem necessary.
Many novelties, too, such as the field telegraph, balloons and signalling, were employed.