The plainest Points, on which not only the Success of an Excursion, but the Lives of Aironauts may depend, are too frequently neglected, as unimportant and trivial. CHAPTER LXVII. THE PROCESS OF INFLATION. [Sidenote: Process of Inflation on the Day of Ascent, viz. on Thursday the 8th Sept. 1785.] Sect. 339. Art. 1. Three cylindric wooden Vessels were sunk more than half their Depth into the Ground: two of them, each, 5 Feet Diameter, and 5 Feet high: the third, 8 Feet in Diameter, and 8 Feet high. An oblong Hole, 4 Inches by 3, was made in each Vessel: and each Hole was furnished with a solid wooden Plug (made tapering) 6 Inches in Length: throu’ these the Vitriol was poured. Besides which, there was an oblong Opening in each Vessel, large enough to admit a Workman, to distribute the Iron equally over the Bottom, and to pour in Buckets of Water: which Openings were well stopped, as soon as the Iron and Water were poured in. As the vitriolic Acid is _corrosive_, burning the Skin or Cloaths; the following Precautions were taken. An occasional moveable Tub was provided, 3 Feet high, and 3 wide: in the Center of whose Bottom was an oblong Aperture, equal to that in each of the Vessels: a corresponding Tin Tube, 6 Inches long, and narrowing to the Bottom, was nailed by its Border on the Inside of the occasional Tub; so as to go easily into any of the oblong Holes. A Bottle of Vitriol being brought in its Basket by two Men, and made to rest on the Top of one of the fermenting Vessels; a third Assistant held the occasional Tub in his Hands, with the Plug-Staff fastened in the Aperture of the Tin Tube; and the Instant a fourth Person opened the Hole in the fermenting Vessel; the Assistant placed the Tin Tube in the Hole, keeping the Plug tight, to prevent the Escape of Gass. The Bottle of Vitriol was then immediately poured into the occasional Tub: and the Bottle being removed, the Plug-Staff was taken out, and the Vitriol suffered to run into the fermenting Vessel: the Assistant watching for the Instant when the Vitriol was run out, in order to _force in_ the Plug-Staff again, and prevent the Escape of Gass: after which, the Tub was rinced with a few Quarts of Water, let also into the Vessel. The same Tub was then removed: the oblong Hole in the fermenting Vessel instantly covered; and, by driving down the solid wooden Plug, continued _Air-tight_; by Means of moist Clay, and a little Water, kept purposely on the Tops of each Vessel, to discover by the Bubbles, whether Gass escaped. [Sidenote: 20 Hundred Weight of Iron-Turnings.] In these Vessels, early on the Morning of the Inflation, were distributed 20 Hundred Weight, at 120lb. Averdupoise to the Hundred, consisting of cast Iron-Filings, and of a Mixture of Cannon-Borings. The Borings were bright and fresh when thrown into the Water: and any Bits of Wood that swam, were skimmed off.