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. A Lever of such a Length and Weight will probably answer every Intention, as no sudden Blows will be required to _fasten or extract it_. The occasional Tub, Tube, Plug, and Staff, shoud be fashioned after this Model. 345. _The Price of the Iron and Vitriol for Inflation._ 2000lb. of Iron Filings or Borings[116] delivered on the Spot, at 6s. a Hundred, £. 6 0 0 16 Bottles of Vitriol, at an Average 38s. a Bottle 30 8 0 Concomitant Expences, 3 12 0 ——————— £. Total 40 0 0 _Observation 1._ A great Saving might be made by conducting the Process in a different Manner.