ANOTHER METHOD OF SUSTAINING A BALLOON OVER WATER, WITHOUT LOSS OF GASS, OR OF BALLAST.
Section 295. Let the Ballast consist of that Kind of Rope (wound on a Reel) that is either by Nature or Art, specifically lighter than fresh Water: as a hollow cylindrical Rope of Silk, in which Corks are thrust: the Silk to be dipped into elastic Varnish, to prevent the Absorption of Water into the Pores: or a common Rope well varnished; or covered over with a cylindric Case of varnished Silk, might answer the same Intention, if Corks or Bladders were tyed at proper Distances: in which Case, the Rope might, at the first Ascent of the Balloon, hang from the Center above the Car, at its full Extent, suppose a Mile or a Mile and half in Length, without the Encumbrance of a Reel.
If Bladders are used; those that hang near the Car shoud not be more than half blown.
By the above Expedient; as soon as the Balloon began to decline, from Evaporation of Gass, or Depression of the Atmosphere, and the lowest Part of the Rope touched the Water; the Balloon woud continue to levitate, in Proportion to the Quantity of Rope sustained on the Surface of the Water.
The Aironaut woud move less swift indeed, but more conveniently; as he woud not be obliged to rise above the Wind: but be able to lower, and raise himself at Pleasure: first, by pulling up a Part of the Rope into the Car; and having there made it fast;
Secondly, by cutting away, as he saw Occasion, the loose End, and Folds of the Rope so drawn into the Car with him.
CHAPTER LV.
ON THE NECESSITY OF ASCERTAINING THE PROPER MODES OF DIRECTION, BY DIFFERENT AND FREQUENT EXPERIMENTS.
On the Necessity of frequent Experiments, in different Modes of Direction.