CHAPTERLIII.ON THE MEANS OF SUSTAINING A BALLOON ABOVE THE SURFACE OF THE WATER, BY A TEMPORARY LOSS OF BALLAST: AND OF RECOVERING THE BALLAST.Sect. 294. Art. 1.THE two Inconveniencies arising from aDischargeof Ballast, while the Balloon is under thePressureof a mediocèanal Column of Air, are,1. First, lest the Balloon shoud rise toohigh; for by opening the Valve in order to descend; Gass escapes: which is anactual Loss: and the Balloon is rendered incapable of supporting its Burden at the same Height, as before.2. The present Impossibility of resuming the Ballast, in order todescend, orcheck the Elevation, on approaching either Shore, or at any other Time.294. 2. These Inconveniencies are to be remedied by the following Methods.IfSandbe the Ballast fixed on; put as much of it into a Bladder by Means of a Tin Funnel, as, whenlessthanhalfblown, it will contain, without sinking below the Surface offreshWater.Preparethe intended Weight of Ballast, in Bladders, after the same Manner.Also toeachBladderwith Ballast, tye another Bladderwithout Ballast, half blown.Tye fast each Set of Bladders, so prepared, with aleathernThong; the Ends of which may be left a few Inches tospare.The Grapple may remain in the Car.294. 3. When the Balloonbeginsto descend over Water; lower out the Cable, by Degrees.Tye a Pair of Bladders, one of which contains Ballast, very tight, round the End of the Cable.Then a second Pair, at such a Distance that the intermediate Part of the Cable, willfloat.Repeat this Process, till the proper Effect is obtained; or the whole Ballast is discharged.294. 4. The Car and Balloon may behauledor wounddownto the Surface of the Water: and the Ballast resumed, as the Balloon approaches the Shore.294. 5. If it be found necessary, the Ballast may bedischargedby cutting thethongs,gradually: or thecable,at once.294. 6. If the Wind becontrary, and the Weathermoderate; the Tide, or Stream may, byCalculationandForesight, be made to serve the Purpose of the Aironaut, in towing the Ballast which floats on its Surface: and thus checking, or gently drawing the Balloon after it.294. 7. In such Cases, the Aironaut woud do well in applying hispropulsiveMachinery.A GENERAL OBSERVATION.294. 8. To prevent the car of theBalloonfrom being drawn out of the Perpendicular, a Circumstance not infrequent; it is necessary to have some Contrivance, by which the Cable shall run throu’ a moveable Pulley, on a Swivel, inthe Center above the Car; and that the Aironaut shall be ableinstantly, by a Screw, or otherways, to fasten the Pulley and Cable so tight, that the Stress shall remain on the Center above the Car, howeverforciblythe Cable may be stretched.
CHAPTERLIII.
Sect. 294. Art. 1.THE two Inconveniencies arising from aDischargeof Ballast, while the Balloon is under thePressureof a mediocèanal Column of Air, are,
1. First, lest the Balloon shoud rise toohigh; for by opening the Valve in order to descend; Gass escapes: which is anactual Loss: and the Balloon is rendered incapable of supporting its Burden at the same Height, as before.
2. The present Impossibility of resuming the Ballast, in order todescend, orcheck the Elevation, on approaching either Shore, or at any other Time.
294. 2. These Inconveniencies are to be remedied by the following Methods.
IfSandbe the Ballast fixed on; put as much of it into a Bladder by Means of a Tin Funnel, as, whenlessthanhalfblown, it will contain, without sinking below the Surface offreshWater.
Preparethe intended Weight of Ballast, in Bladders, after the same Manner.
Also toeachBladderwith Ballast, tye another Bladderwithout Ballast, half blown.
Tye fast each Set of Bladders, so prepared, with aleathernThong; the Ends of which may be left a few Inches tospare.
The Grapple may remain in the Car.
294. 3. When the Balloonbeginsto descend over Water; lower out the Cable, by Degrees.
Tye a Pair of Bladders, one of which contains Ballast, very tight, round the End of the Cable.
Then a second Pair, at such a Distance that the intermediate Part of the Cable, willfloat.
Repeat this Process, till the proper Effect is obtained; or the whole Ballast is discharged.
294. 4. The Car and Balloon may behauledor wounddownto the Surface of the Water: and the Ballast resumed, as the Balloon approaches the Shore.
294. 5. If it be found necessary, the Ballast may bedischargedby cutting thethongs,gradually: or thecable,at once.
294. 6. If the Wind becontrary, and the Weathermoderate; the Tide, or Stream may, byCalculationandForesight, be made to serve the Purpose of the Aironaut, in towing the Ballast which floats on its Surface: and thus checking, or gently drawing the Balloon after it.
294. 7. In such Cases, the Aironaut woud do well in applying hispropulsiveMachinery.
294. 8. To prevent the car of theBalloonfrom being drawn out of the Perpendicular, a Circumstance not infrequent; it is necessary to have some Contrivance, by which the Cable shall run throu’ a moveable Pulley, on a Swivel, inthe Center above the Car; and that the Aironaut shall be ableinstantly, by a Screw, or otherways, to fasten the Pulley and Cable so tight, that the Stress shall remain on the Center above the Car, howeverforciblythe Cable may be stretched.