Benjamin Franklin to Joseph Banks 30-Aug-1783

Franklin describes the flight of Jacques-Alexandre-Cesar Charles on Wednesday, 27 August 1783.

A hollow Globe 12 feet Diameter was formed of what is called in England Oiled Silk, here Taffetas gommé, the Silk being impregnated with a solution of Gum elastic in Lintseed Oil, as is said. The parts were sewed together while wet with the Gum, and some of it was afterwards passed over the Seams, to render it as tight as possible.
It was afterwards filled with the inflammable Air that is produced by pouring Oil of Vitriol upon Filings of Iron, when it was found to have a tendency upwards so strong as to be capable of lifting a weight of 39 Pounds, exclusive of its own Weight which was 25 lbs and the Weight of the Air contain'd.

(Oil of Vitriol is probably sulphuric acid.)

He confirms that the balloon went up "till it enter'd the Clouds, when it seem'd to me scarce bigger than an Orange, and soon after became invisible, the Clouds concealing it."

He writes that the Frères Montgolfier are working on another balloon, 38' in diameter, and "to be filled with a different Air, not yet made Public, but cheaper than that produc'd by the Oil of Vitriol, of which 200 Paris Pints were consum'd in filling the other."

Finally:

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 Freet, than 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 byPullies 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.

Sources

• Rotch, 1909, Conquest of the Air, pp. 43–49

Sender	Benjamin Franklin
Recipient	Joseph Banks
Date sent	30-Aug-1783
From location	Passy, France
To location	London?
Communication type
Language	English
Refers to flight?	1
Tech fields	balloon, LTA, hydrogen, fun, passengers, cargo, propulsion
Length (in words)
Full text available