CHAPTER LV.
ON THE NECESSITY OF ASCERTAINING THE PROPER MODES OF DIRECTION, BY DIFFERENT AND FREQUENT EXPERIMENTS.
[Sidenote: On the Necessity of frequent Experiments, in different Modes of Direction.]
Section 296. The Necessity of making frequent Experiments, in order to prove how far the Balloon is capable of Direction, by different Combinations of the mechanical Powers, is so apparent; that no Balloon shoud rise a second Time, without the Application of Machinery to that End.
Each Candidate for Fame, as Proprietor of a Balloon for _public Exhibition_, ought to vie in his Pretensions to a Superiority of Manouvres.
Their respective Performances woud appear in the public Papers; and Decisions be made to the Advantage of the Art.
For it is probable, that by such _Comparison_ chiefly;—the +comparison+ of _experimental Blunders_ and _Mistakes_, and not by an Union of Theory and Practice, cemented by liberal Patronage, the Balloon can arrive to any Degree of Perfection, in a Country, which is the Scene of _perpetual Contention_: where the Sum of Life seems devoted but to +party+; and where the _precious_ Time of the +great+ is sunk in Luxury, and their _exalted_ Talents lost in the _Labyrinth_ of Politics.
[Sidenote: Precautions to secure a Landing.]
297. _To strive against the Stream_ is proverbially impossible: and it woud be literally so, to attempt by any Kind of Machinery to force the large Surface of a Balloon, with any Degree of Velocity, against _a Stream of_ +air+. (Section 201.)
Ships, which have the Aid of an Element 800 Times _denser_ than the +air+, are obliged to wait _in Port_, till the Wind is favourable. But neither is this considered as an Argument against _maritime Navigation_: nor does the _Perfection_ of the Balloon require its Ascent in a Storm: tho’ the Preference due to the Balloon, on such Occasion, woud be decisive in its Favour: as the latter woud presently surmount the Wind, and _lie to_, in the _calm Air above_ it.
Sect. 298. Art. 1. By Wings, or some propulsive Machinery, acting forcibly in a Direction required, and with Ease to the _Operator_; +two+ _useful Manouvres_ may be attempted, and will frequently be _found successful_.
[Sidenote: _First Manouvre_: to secure the Landing in windy Weather.]
298. Art. 2. First, To +retard+ the Course of the Balloon during its Descent; in such a Manner, as to prevent the Wind from _damaging_ the _Machine_, or _snapping the Cable_: and thus to land with Safety, and at the _smallest Distance_ +beyond+ the Place assigned.
[Sidenote: Preparatory Apparatus: and _Signal-Rope_.]
298. 3. A _silken_, or other _light_ Rope is to be provided: and to run throu’ a _snatch Block_ fastened to a +rudder+, or to the +car+, as in Crosbie’s Balloon.[98]
Which Rope _alone_ woud lessen immediate and unforeseen Danger, by using the Balloon as a Sail, if it actually alighted on the Water.
298. Art. 4. The same Rope being _a Mile_, or _a Mile and Half_ in Length; the _Whole_, or a Part of it, might be suffered to run off the Wheel, and, falling on the Surface _below_, in _misty_ Weather, woud serve as a Signal to determine whether the Aironaut was over Land, or Water.
Also by winding up his Wheel, he might, if the Weather was moderate, bring himself _down_ to the Grapple, which might be so contrived as to _run down_ the Rope, and remain at the Bottom, by Means of a Knot, or other Check.
He might also _loose_ his Grapple, and _rise_ again: or when down; pull the Valve-Cord, and land.
298. 5. With a +second+ short Cable, snatch Block and Grapple, he woud be able to _moor_ the Balloon, from which, he might, by procuring the Country People to load the Car with fresh Ballast equal in Weight to himself;—get out, and even leave the Balloon in their Care.
The Precaution of knowing whether he was over a fresh Water-Lake, (for he might hear the Sea) might be useful in misty and low cloudy Weather by Day, or during the Night; without expending Gass in the _exploratory_ Descent.
298. 6. To facilitate the landing, the _Signal-Rope_ may be used to the greatest Advantage, particularly in windy Weather; by _lowering out_ a Part, or the Whole, whether a Mile, or Mile and half, so that the Grapple may take Effect on the Ground, at the Distance of its Length _by Estimation_, _short_ of the Place where the Balloon is intended to land.
As soon as the Grapple _holds_; it is in the Option of the Aironaut, to tye Parcels of his Ballast _loosely_ round the Cable, to run downwards along with it.
(For _which Purpose_, Iron-Rings with _Spring-Swivels_, which _open_ by _Pressure_ of the Fingers, and _shut_ of themselves, might answer better than the _leathern Thongs_, as the former might be put, in _an Instant_, round the Cable, and woud run down _quicker_.)
These Parcels of Ballast are to be sent down, in Succession, till the Balloon has acquired such Degrees of +false levity+, as will be sufficient to counteract that Tendency which the Wind will have to _depress_ the Car of the Balloon forcibly on the Surface, so long as it is connected with the Grapple _on the Ground_.
298. 7. When this Point is effected, the Balloon will remain suspended in the Air; and being acted upon by the Wind, will be pressed into a Direction approaching to an horizontal Line, in Proportion to the encreasing Power of the Wind.
And here the Necessity of having the Cable fastened to a Center above the Car, in order to retain its Perpendicularity, is most evident.
The Aironaut, in this Situation, may venture to wind up the Cable _gradually_, and descend, to the Grapple.
298. 8. Secondly: When the different Currents of Air, have been tried by Descent and Ascent of the Pioneer-Balloon,[99] and found to be _all_ unfavourable; the Aironaut is to _rise_ still higher, into a Calm, pursue his Course horizontally in the +blue serene+, by propulsive Machinery: estimating the Velocity, by the _evident Resistance_ of the half Mile white Flag described in Section 12, 13. and 12, 15. hanging at a proper Distance _below_, and of that which hangs loosely at the Side of the Car, to shew a Change in the Direction of the Wind, (then made by a Resistance of the Air): or he may judge o£ the Velocity and Direction, by the _Flight_ of a _Feather_, repeatedly let loose at certain Intervals of Time.