CHAPTERIII.ADDRESSED TO AIRONAUTS.New Kind of Cable and Reel recommended.Section 13.THE following Anchor and Cable, for greater Safety and some particular Uses, are recommended as an Improvement.AstrongIron double Grapple, moving on a Swivel, fastened to aRope,[5]half a Mile, or bettera Milelong: 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 moveableHandles 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 theAscent.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 tostrain, 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 withan 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 theResistancefrom the Air: cut away Ends of Cords; tear off Ornaments: part with Shoes, Cloaths. All which must be madelooseandreadyto 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 theoppositeSides of the upper Hoop; so that the Feet may not touch the Bottom of the Car. The Knees shoud likewise bebent. 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, whichalonewill, at all Times, ensure an easy Descent.SIGNS WHEREBY TO JUDGE WHETHER THE BALLOON IS RISING OR FALLING.SIGNS OF RISING.Signs of Ascent or Descent.16. 1. When the Aironaut perceives a Pressure upwards against the Soles of his Feet.2. When some Objects, on the Surface of the Earth immediately below, diminish, and others disappear.3. When an upper Cloud approaches or involves the Balloon.4. When a lower Cloud leaves the Balloon.5. When Rain Snow or Hail beatviolentlyagainst the Top of the Balloon.6. When Feathers, Balloon-Flag, or Ribbon seem to be drawn forcibly downwards.7. When Objects on Earth, or among Clouds below the Balloon, rise and present themselvesbeyond those, which, the moment before, were thought most distant.8. When the Balloon appears broader and shorter; also fuller at the Bottom; being more distended than at the first Ascent.SIGNS OF DESCENT.Signs of Descent.17. 1. When the Aironaut perceives the Bottom of the Car withdrawing itself from the Pressure against the Soles of his Feet.2. When Objects on Earth, and surrounding Prospects encrease in Magnitude and Number.3. When a lower Cloud approaches or involves the Balloon.4. When an upper Cloud leaves the Balloon.5. When Weather beats against the Bottom of the Car or Balloon.6. When Feathers, Balloon-Flag, or Ribbon appear to be drawn upwards.7. When the most distant Objectsset, and disappear.8. When the Balloon seems taller; and its lower Hemisphere less distended, tho’ continuingtight.SIGNS OF PROGRESSIVE HORIZONTAL MOTION.Signs of progressive Motion deceitful.18. These are equivocal and deceitful.When the Aironaut has lost Sight of the Earth by intervening Clouds; the Balloon seems at Rest, and only the lower Clouds appear to move: whereas the contrary may be true, the Clouds may rest, and only the Balloon move.In this Case, Attention must be paid to the half Mile white Flag, whose Situation and Motion must be observed, with respect to the Balloon, andto the Earth before the Cloud intervened. If the Flag retains its Situation with Respect to the Balloon, it may be inferred that no Change in the Direction has happened: if its Situation alters, the Sun or Compass is to be observed: and an Estimate made of the new Current of Air by which the Balloon is affected: its Velocity, Sound, Temperature, &c.To descend when lost.19. But to acquire a Certainty of course, it will be proper to descend below the Cloud: or move by Compass, Map, and a Knowledge of the Country: or try the long Cable (Section 13.)Signs of Wind horizontal.20. It is likewise necessary to know theSigns of Wind, or Currents of Air.SIGNS OF NEW AND SUDDEN HORIZONTAL CURRENTS.When the Feathers, Balloon-Flag, or Ribbon, compared with Sun or Compass, take a new and sudden horizontal Direction.21.of currents from above: properly namedWaves Torrents and Tide of Air.Signs of depressing Torrents and Tide of Air.They are very frequent, and require to be guarded against: are sometimes or long Continuance, at other Times momentary: against the first throw out Ballast at the Height of a Quarter of a Mile, but not before, oras hereafter directed: when momentary, and above that Height, Nothing is to be apprehended: the Balloon will appear broader and recover its Form.
CHAPTERIII.
New Kind of Cable and Reel recommended.
Section 13.THE following Anchor and Cable, for greater Safety and some particular Uses, are recommended as an Improvement.
AstrongIron double Grapple, moving on a Swivel, fastened to aRope,[5]half a Mile, or bettera Milelong: 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 moveableHandles of Wood round them. The Reel may be furnished with sudden Checks; or gradual Clamps, as in a Mil, to retard the Velocity.
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 theAscent.
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.
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 tostrain, 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 withan 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 theResistancefrom the Air: cut away Ends of Cords; tear off Ornaments: part with Shoes, Cloaths. All which must be madelooseandreadyto 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 theoppositeSides of the upper Hoop; so that the Feet may not touch the Bottom of the Car. The Knees shoud likewise bebent. 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, whichalonewill, at all Times, ensure an easy Descent.
Signs of Ascent or Descent.
16. 1. When the Aironaut perceives a Pressure upwards against the Soles of his Feet.
2. When some Objects, on the Surface of the Earth immediately below, diminish, and others disappear.
3. When an upper Cloud approaches or involves the Balloon.
4. When a lower Cloud leaves the Balloon.
5. When Rain Snow or Hail beatviolentlyagainst the Top of the Balloon.
6. When Feathers, Balloon-Flag, or Ribbon seem to be drawn forcibly downwards.
7. When Objects on Earth, or among Clouds below the Balloon, rise and present themselvesbeyond those, which, the moment before, were thought most distant.
8. When the Balloon appears broader and shorter; also fuller at the Bottom; being more distended than at the first Ascent.
Signs of Descent.
17. 1. When the Aironaut perceives the Bottom of the Car withdrawing itself from the Pressure against the Soles of his Feet.
2. When Objects on Earth, and surrounding Prospects encrease in Magnitude and Number.
3. When a lower Cloud approaches or involves the Balloon.
4. When an upper Cloud leaves the Balloon.
5. When Weather beats against the Bottom of the Car or Balloon.
6. When Feathers, Balloon-Flag, or Ribbon appear to be drawn upwards.
7. When the most distant Objectsset, and disappear.
8. When the Balloon seems taller; and its lower Hemisphere less distended, tho’ continuingtight.
Signs of progressive Motion deceitful.
18. These are equivocal and deceitful.
When the Aironaut has lost Sight of the Earth by intervening Clouds; the Balloon seems at Rest, and only the lower Clouds appear to move: whereas the contrary may be true, the Clouds may rest, and only the Balloon move.
In this Case, Attention must be paid to the half Mile white Flag, whose Situation and Motion must be observed, with respect to the Balloon, andto the Earth before the Cloud intervened. If the Flag retains its Situation with Respect to the Balloon, it may be inferred that no Change in the Direction has happened: if its Situation alters, the Sun or Compass is to be observed: and an Estimate made of the new Current of Air by which the Balloon is affected: its Velocity, Sound, Temperature, &c.
To descend when lost.
19. But to acquire a Certainty of course, it will be proper to descend below the Cloud: or move by Compass, Map, and a Knowledge of the Country: or try the long Cable (Section 13.)
Signs of Wind horizontal.
20. It is likewise necessary to know theSigns of Wind, or Currents of Air.
When the Feathers, Balloon-Flag, or Ribbon, compared with Sun or Compass, take a new and sudden horizontal Direction.
21.of currents from above: properly namedWaves Torrents and Tide of Air.
Signs of depressing Torrents and Tide of Air.
They are very frequent, and require to be guarded against: are sometimes or long Continuance, at other Times momentary: against the first throw out Ballast at the Height of a Quarter of a Mile, but not before, oras hereafter directed: when momentary, and above that Height, Nothing is to be apprehended: the Balloon will appear broader and recover its Form.