I received your friendly Letter of the 7th Inst. I am glad my Letters respecting the Aerostatic Experiment were not unacceptable. But as more perfect Accounts of the Construction and Management of that Machine have been and will be published before your Transactions, and from which Extracts may be made that will be more particular and therefore more satisfactory, I think it best not to print those Letters. I say this in answer to your Question; for I did not indeed write them with a view of their being inserted. Mr. Faujas de St. Fond acquainted me yesterday that a Book on the Subject which has been long expected, will be publish'd in a few Days, and I shall send you one of them. Enclosed is a Copy of the _Procès verbal_ taken of the Experiment made 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 rarified 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 rarified 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. _La Machine poussée par le Vent s'est dirigée sur une des Allées du Jardin._ That is against the Trees of one of the Walks. The Gallery hitched among the top Boughs of those Trees which had been cut and were stiff while the Body of the Balloon lean'd beyond and seemed likely to overset. I was then in great Pain for the Men, thinking them in danger of being thrown out, or burnt for I expected that the Balloon being no longer upright the Flame would have laid hold of the inside that leaned over it. But by means of some Cords that were still attach'd to it, it was soon brought upright again, made to descend, & carried back to its place. It was however much damaged.