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.
If it is required to rise still higher; gradually throw out Ballast, and repeat the Operations.
The proposed Quantity of Ballast being thrown out, the Balloon will have acquired its utmost Height, and become stationary, i. e. neither rise nor fall.
The self Descent of the Balloon is only in Proportion, as the inflammable Air or Gass escapes thro’ imperceptible Holes in the Silk or Seams.
2dly. To prevent too precipitate a Fall.
2ndly. Caution against too precipitate a Fall.
15. 1st. Tye, or compress the Mouth of the Balloon, for a Moment; which must always be opened, on observing that the Balloon is again risen to so great a Height as to strain, or be distended as above mentioned.
2d. In descending, throw out Ballast, when the Balloon is within a Quarter of a Mile of the Ground, but not before, i. e. at 26 Inches by the Barometer: and, if the Fall is precipitate, not less than 25 Pounds Averdupoise, Pound by Pound, or at once, if there should be Occasion.
3d. In Case of Accident, as the Escape of Gass; or if the Balloon be not furnished with an Equatorial Hoop; prepare to throw out all the Ballast at the above Height, but not before; as the more forcible the Fall,[6] the greater the Resistance from the Air: cut away Ends of Cords; tear off Ornaments: part with Shoes, Cloaths. All which must be made loose and ready to throw out, at the Moment the Balloon begins to descend. Before the Landing, particular Care must be taken, that the Weight of the Aironaut be sustained, by grasping the Hands round the opposite Sides of the upper Hoop; so that the Feet may not touch the Bottom of the Car. The Knees shoud likewise be bent. Repeating the above, at each Rebound of the Balloon, if any; the Aironaut will alight in the gentlest Manner: and probably the Balloon may act as a Parashute or Umbrella, which alone will, at all Times, ensure an easy Descent.