A strong Iron double Grapple, moving on a Swivel, fastened to a Rope,[5] half a Mile, or better a Mile long: and, if not all; a Part of which at least, at the Distance and for the Length of ten Yards from the Grapple, shoud be of Silk, as a non Conductor: also other ten Yards, at its upper End, counting from the Reel or Pulley to which the Silk shoud be tyed.
The Reel or Pulley being at least eighteen Inches in Diameter, and fixed vertically in the Center of the upper Hoop, seven Feet above the Bottom of the Car; by Means of three or four Iron Rods fastened in the Bottom of the Car, and meeting together above the Reel: the Rods so strong as to prevent the Shock which otherwise the Aironaut woud receive in alighting on the Ground.
The Reel shoud have one, or two Iron Winches or Handles, one at each End of the Reel; with moveable Handles of Wood round them. The Reel may be furnished with sudden Checks; or gradual Clamps, as in a Mil, to retard the Velocity.
SIGNS TO BE OBSERVED, WHEN IN THE AIR.
Cautions against two Extremes.
14. The two Extremes to be avoided are, too lofty an Ascent: and too precipitate a Fall.
1st. Too lofty an Ascent.
The former is to be apprehended when Balloon has swelled considerably, and strains as if ready to burst; from the Shape of an inverted Cone, or Children’s Top, changed to that of an oblate Spheroid, or Turnep.
It is therefore necessary to look up at the Balloon from Time to Time: and either open the Mouth, or as it is sometimes called the Neck, for an Instant; or draw the Valve; which is done by pulling a Cord fixed at the Top of the Machine and running thro’ it to the Hand, till the Balloon only appears full without straining.
These Operations are to be occasionally repeated during the Ascent.