a Field in which Reviews are sometimes made, lying between the Military School and the River. There it was held down by a Cord, till 5 in the Afternoon, when it was to be let loose. Care was taken before the Hour to replace what Portion had been lost of the inflammable Air, or of its Force, by injecting

more.

It is supposed that not less than 50,000 People were assembled to see the Experiment. The Champ de Mars being surrounded by Multitudes, and vast Numbers on the opposite Side of the River.

At 5 0 Clock Notice was given to the Spectators by the Firing of two Cannon, that the Cord was about to be cut. And presently the Globe was seen to rise, and that as fast as a Body of 12 feet diameter with a force only of 39 pounds, could be suppos'd to move the resisting Air out of its way. There was some Wind, but not very strong. A little Rain had wet it, so that it shone, and made an agreable Appearance. It diminish'd in Apparent Magnitude as it rose, 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.

The Multitude separated, all well satisfied & much delighted with the Success of the Experiment, and amusing one another with Discourses of the various Uses it may possibly be apply'd to, among which many were very extravagant. But possibly it may pave the Way to some Discoveries in Natural Philosophy of which at present we have no Conception.

A Note secur'd from the Weather had been affix'd to the Globe, signifying the Time & Place of its Departure, and praying those who might happen to find it, to send an Account

of its State to certain Persons at Paris. No News was heard of it till the next Day, when Information was receiv'd, that it fell a little after 6 oClock at Gonesse, a Place about 4 Leagues distance; and that it was rent open, and some say had Ice in it. It is suppos'd to have burst by the Elasticity of the contain'd Air when no longer compress'd by so heavy an Atmosphere.

One of 38 feet Diameter is preparing by M. Mongolfier himself at the Expence of the Academy, which is to go up in a few Days. I am told it is constructed of Linen & Paper, and is 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.

It is said that for some Days after its being fill'd, the Ball was found to lose an eighth Part of its Force of Levity in 24 Hours: Whether this was from Imperfection in the Tightness of the Ball, or a Change in the Nature of the Air, Experiments may easily discover.

I thought it my Duty, Sir, to send an early Account of this extraordinary Fact, to the Society which does me the honour to reckon me among its Members; and I will endeavour to make it more perfect, as I receive farther Information.

With great Respect, I am, Sir,

P. S.

[B. FRANKLIN.]

Since writing the above, I am favour'd with your kind Letter of the 25th I am much oblig'd to you for the Care you have taken to forward the Transactions, as well as to the Council for so readily ordering them on Application. Please to

accept and present my Thanks.

I just now learn, that some Observers say, the Ball was 150

VOL. IX-G

seconds in rising, from the Cutting of the Cord till hid in the Clouds; that its height was then about 500 Toises, but, mov'd 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 touch'd the Ground, that there was some living Animal in it, and attack'd it with Stones and Knives, so that it was much mangled; but it is now brought to Town & will be repaired.

The great one of M. Mongolfier, 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 a Force of Levity equal to 1500 pounds weight. A Philosopher here, M. Pilatre de 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 M. Mongolfier'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 & improving this Discovery, that probably we shall soon make considerable Progress in the Art of constructing and Using the Machines.

Among the Pleasantries 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 Instruments 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 & suspended under such a Globe so as to leave no more of Weight pressing the Earth with their Feet, 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 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 contrived to give People an extensive view of the Country, by running them upon an Elbow Chair a Mile high for a Guinea, &c. &c.

[A Pamphlet is printing in which we are to have a full and perfect Account of the Experiments hitherto made, & I will send it to you. M. Mongolfier's Air to fill the Globe has hitherto been kept secret. Some suppose it to be only common Air heated by passing thro' the Flame of burning Straw, & thereby extreamly rarified. If so its Levity will soon be diminished by Condensation when it comes into the cooler Regions above.

Sept. 2d. I add this paper just now given me, B. F. The print contains a view of Champ de Mars, and the ball in the air with this subscription:

Experience de la machine aérostatique de Messrs. de Montgolfier, d'Anonai en Vivarais, réepétée à Paris le 27 Août. 1783 au Champ de Mars, avec un ballon de taffetas enduit de gomme elastique, de 36 pieds 6 onces de circonference. Le ballon plein d'air inflammable a été executé par Mons.

I have been too much and too closely engaged in public Affairs, since his being here, to enjoy all the Benefit of his Conversation you were so good as to intend me. I hope soon to have more Leisure, and to spend a part of it in those Studies, that are much more agreable to me than political Operations.

I join with you most cordially in rejoicing at the return of Peace. I hope it will be lasting, and that Mankind will at length, as they call themselves reasonable Creatures, have Reason and Sense enough to settle their Differences without cutting Throats; for, in my opinion, there never was a good War, or a bad Peace. What vast additions to the Conveniences and Comforts of Living might Mankind have acquired, if the Money spent in Wars had been employed in Works of public utility! What an extension of Agriculture, even to the Tops of our Mountains: what Rivers rendered navigable, or joined by Canals: what Bridges, Aqueducts, new Roads, and other public Works, Edifices, and Improvements, rendering England a compleat Paradise, might have been obtained by spending those Millions in doing good, which in the last War have been spent in doing Mischief; in bringing Misery into thousands of Families, and destroying the Lives of so many thousands of working people, who might have performed the useful labour!

I am pleased with the late astronomical Discoveries made by our Society.' Furnished as all Europe now is with Academies of Science, with nice Instruments and the Spirit of Experiment, the progress of human knowledge will be rapid, and discoveries made, of which we have at present no Conception. I begin to be almost sorry I was born so soon, 1 The Royal Society. — ED.