And as the Intervals encreased, a Judgment was formed, that the Operation began to be less vigorous: and consequently that it became necessary, either to renew it by an Addition of more Vitriol and Water in the same Vessel, or to set the other small Vessel in Fermentation, the latter of which Mr. Lunardi preferred: this happened about half an Hour after the Vitriol was poured into the first Vessel.
342. After the second half Hour, eight Bottles were poured, by four at a Time, into the great Vessel.
And at one o’Clock, the Balloon, without any farther Trouble was beautifully inflated.
No Iron Rods were used to stir up the Borings or Filings at the Bottom of the Vessels: the Vitriol being found so heavy as to penetrate them as fast as the Iron, contiguous to the Vitriol, had parted with its Gass.
At each of the two former Inflations, a similar Accident happened which may be imputed to the same Cause.
343. During the first Inflation, the solid oblong wooden Plug fell into one of the fermenting Vessels: the hot Vapour, forcibly issuing from the Orifice, was condensed in the Form of a white Smoke; which being mistaken by the Company, a Cry was immediately heard of Fire, Fire: on which the Workmen retreated. Mr. Lunardi incautiously thrust his Arm into the Orifice to extract the Plug: at the same Time being much burnt, and failing in the Attempt; the Gass continued to escape, till a new Plug was prepared.
344. During the second Inflation, one of the Plugs being driven too forcibly; it was with Difficulty extricated, by the Strokes of a Hammer against the Sides of it, which tended at the same Time to displace the Boards forming the Top or Head of the Vessel: and, a little afterwards, occasioned it to burst, unexpectedly inwards,[115] rendering the Vessel useless for the Purpose of Inflation.
Observation. Therefore instead of the solid oblong wooden Plug, a circular Hole, 4 Inches Diameter shoud be drilled in each Vessel: and a corresponding solid wooden Plug 8 Inches long, 5 Diameter at the upper Part, and tapering to near 3 at the Bottom, shoud be prepared by the Turner.
In the upper Part of the Solid shoud be turned an inside Screw, to which an outside Screw of the circular Plug-Staff, made of Oak, Ash, or other heavy Wood, 4 Feet long, and 4 Inches Diameter, shoud be adapted: the Worm of the Screw to be 5 Inches long.
A wooden Peg of Ash, about a Quarter of an Inch Diameter, may be put throu’ a Hole near the Top of the Staff, as a Handle.