Section 314. THE Air-Bottle can be attended with no Sort of Danger. For, if it burst; the only Effect is to raise the Balloon: which is made to descend, at Pleasure, by opening either the lower or upper Valve.
Whereas an interior Balloon condensed with common Air, presses against the surrounding exterior Gass: and the Gass, against the inside of the great Balloon, when the latter is in an elevated and rarefied Atmosphere; which Atmosphere, in Proportion to its Height, makes less Resistance to the Outside of the great Balloon: and thereby encreases its Tendency to a Rupture.
By the Application of the Air-Bottle, which will be to a Balloon, what an Air-Bladder, or Swim is to a Fish; a concomitant Advantage is derivable.
For the common Balloon and Air-Bottle, which may be called a double balloon, will, in their present imperfect State, be able to remain a Day, or perhaps a Couple of Days in the Air: there being no Loss of Gass: unless by Evaporation, throu’ the Pores of the Silk.
And this Advantage of a double Balloon may be effected with little expence (except that of a complete Net) to the different Proprietors, who may make alternate Voyages, with the Balloons thus united: one being inflated with Gass; the other occasionally with three or more Atmospheres of common Air condensed.
CHAPTER LX.
HINTS FOR THE DIRECTION OF THE BALLOON.
Sect. 315. Art. 1. IN the London Chronicle, from the 20th to the 22d of August, 1785, is a Letter from Bury, containing an Account of Mr. Poole’s Balloon, with the following Circumstance, viz. “It was found necessary, before the Balloon was liberated, to cut away the Wings, intended to act as Sails, which had been constructed by an ingenious Piedmontese, patronized by lord orford, and which it was supposed, woud have contributed to facilitate the Direction of the Balloon, but were found greatly to retard the Celerity of its Motion.”
Now if any Credit can be given to Newspaper Accounts, (that of the Beccles Balloon being an entire Fable,) it is to be lamented that the Wings were cut away for the Reason assigned: as it seems the only one that could properly be offered for applying them.