P. S. I just now learned that some observers say, the Ball was 150 Seconds in rising, from the cutting of the Cord till hid in the Clouds; that its height was then about 500 Toises, but, being moved out of the Perpendicular by the Wind, it had made a Slant so as to form a Triangle, whose base on the Earth was about 200 Toises. It is said the Country People who saw it fall were frightened, conceiv’d from its bounding a little, when it touched the Ground, that there was some living Animal in it, and attack’d with Stones and Knives, so that it was much mangled; but it is now brought to Town and will be repair’d.
The great one of M. Montgolfier is to go up, as is said, from Versailles, in about 8 or 10 days. It is not a Globe but of a different Form, more convenient for penetrating the Air.
It contains 50,000 cubic Feet, and is supposed to have Force of Levity equal to 1,500 pounds weight. A Philosopher here, M. Pilâtre du Rozier, has seriously apply’d to the Academy for leave to go up with it, in order to make some experiments. He was complimented on his Zeal and Courage for the Promotion of Science, but advis’d to wait till the management of these Balls was made by Experience more certain & safe. They say the filling of it in Montgolfier’s Way will not cost more than half a Crown. One is talk’d of to be 110 feet Diameter. Several gentlemen have ordered small ones to be made for their Amusement. One has ordered four of 15 feet Diameter each; I know not with what Purpose; but such is the present Enthusiasm for promoting and improving this Discovery, that probably we shall soon make considerable Progress in the art of constructing and using the Machines.
Among the Pleasanteries Conversation produces on this subject, some suppose Flying to be now invented, and that since Men may be supported in the Air, nothing is wanted but some light handy instrument to give and direct Motion. Some think Progressive Motion on the Earth may be advanc’d by it, and that a Running Footman or a Horse slung and suspended under such a Globe so as to have no more of Weight pressing the Earth with their Feet, then Perhaps 8 or 10 pounds, might with a fair Wind run in a straight Line across Countries as fast as that Wind, and over Hedges, Ditches & even Waters. It has been even fancied that in time People will keep such Globes anchored in the Air, to which by Pullies they may draw up Game to be preserved in the Cool & Water to be frozen when Ice is wanted. And that to get Money, it will be contriv’d to give People an extensive View of the Country, by running them up in an Elbow Chair a Mile high for a Guinea, &c., &c.
B. Franklin.
Passy, Nov. 22d, 1783.
... Enclosed is a copy of the Proces verbal taken of the Experiment yesterday in the Garden of the Queen’s Palace la Muette, where the Dauphin now resides, which being near my House I was present. This Paper was drawn up hastily, and may in some Places appear to you obscure; therefore I shall add a few explanatory Observations.
This Balloon was larger than that which went up from Versailles and carried the Sheep, &c. Its bottom was open, and in the middle of the Opening was fixed a kind of Basket Grate, in which Faggots and Sheaves of Straw were burnt. The Air rarefied in passing thro’ this Flame rose in the Balloon, swell’d out its sides, and Fill’d it.
The Persons who were plac’d in the Gallery made of Wicker, and attached to the Outside near the Bottom, had each of them a Port thro’ which they could pass Sheaves of Straw into the Grate to keep up the Flame, & thereby keep the Balloon full. When it went over our Heads, we could see the Fire which was very considerable. As the Flame slackens, the rarefied Air cools and condenses, the Bulk of the Balloon diminishes and it begins to descend. If those in the Gallery see it likely to descend in an improper Place, they can by throwing on more Straw, & renewing the Flame, make it rise again, and the Wind carries it farther.
One of these courageous Philosophers, the Marquis d’Arlandes, did me the honour to call upon me in the Evening after the Experiment, with Mr. Montgolfier, the very ingenious Inventor. I was happy to see him safe. He informed me that they lit gently, without the least Shock, and the Balloon was very little damaged.
This method of filling the Balloon with hot Air is cheap and expeditious, and it is supposed may be sufficient for certain purposes, such as elevating an Engineer to take a view of an Enemy’s Army, Works, &c., conveying Intelligence into, or out of a besieged Town, giving Signals to distant places, or the like.