1. First, lest the Balloon shoud rise too high; for by opening the Valve in order to descend; Gass escapes: which is an actual 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 to descend, or check the Elevation, on approaching either Shore, or at any other Time.
294. 2. These Inconveniencies are to be remedied by the following Methods.
If Sand be the Ballast fixed on; put as much of it into a Bladder by Means of a Tin Funnel, as, when less than half blown, it will contain, without sinking below the Surface of fresh Water.
Prepare the intended Weight of Ballast, in Bladders, after the same Manner.
Also to each Bladder with Ballast, tye another Bladder without Ballast, half blown.
Tye fast each Set of Bladders, so prepared, with a leathern Thong; the Ends of which may be left a few Inches to spare.
The Grapple may remain in the Car.
294. 3. When the Balloon begins to 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.