Benjamin Franklin and the First Balloons

It is said that for some Days after its being filled, 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,

Your most obedient and most humble Servant

B. FRANKLIN

Sir Joseph Banks, Bart.

P. S. Since writing the above, I am favour’d with your kind Letter of the 25th. I am much obliged 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 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 frightned, conceiv’d from its bounding a little, when it touched 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 and will be repaired.

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 1500 pounds weight. A Philosopher here, M. Pilatre 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 M. 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 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 and suspended under such a Globe so as to have 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 up in an Elbow Chair a Mile high for a Guinea &c. &c.

B. F.

(A HOT AIR BALLOON CARRYING ANIMALS.)

Passy, Oct. 8, 1783.

Sir,

The Publick were promised a printed particular Account of the Rise & Progress of the Balloon Invention, to be published about the End of last month. I waited for it to send it to you, expecting it would be more satisfactory than anything I could write; but it does not appear. We have only at present the enclosed Pamphlet, which does not answer the expectation given us. I send you with it some prints. That of the Balloon raised at Versailles is said to be an exact representation. I was not present, but am told it was filled in about ten minutes by means of burning Straw. Some say water was thrown into the flame, others that it was Spirits of Sal Volatile. It was supposed to have risen about 200 Toises: But did not continue long at that height, was carried horizontally by the Wind, and descended gently as the Air within grew cooler. So vast a Bulk when it began to rise so majestically in the Air struck the spectators with surprise and Admiration. The Basket contained a sheep, a duck, and a Cock, who, except the Cock, received no hurt by the fall.

The Duke de Crillon made a feast last week in the Bois de Boulogne, just by my habitation, on occasion of the Birth of two Spanish Princes; after the Fireworks we had a Balloon of about 5 feet Diameter filled with permanent inflammable Air. It was dismissed about One aClock in the Morning. It carried under it a large Lanthorn with inscriptions on its sides. The Night was quite calm and clear, so that it went right up. The appearance of the light diminished gradually till it appeared no bigger than one of the Stars, and in about twenty minutes I lost sight of it entirely. It fell the next Day on the other side of the same Wood near the Village Boulogne, about half after twelve, having been suspended in the Air eleven hours and a half. It lodged in a tree, and was torn in getting it down; so that it cannot be ascertained whether it burst when above, or not, tho’ that is supposed. Smaller Repetitions of the Experiment are making every day in all quarters. Some of the larger Balloons that have been up are preparing to be sent up again in a few Days; but I do not hear of any material improvements yet made either in the mechanical or Chemical parts of the Operation. Most is expected from the new one undertaken upon subscription by Messieurs Charles and Robert, who are Men of Science and mechanic Dexterity. It is to carry up a Man. I send you enclosed the Proposals, which it is said are already subscribed to by a considerable number and likely to be carried into execution. If I am well at the Time, I purpose to be present, being a subscriber myself, and shall send you an exact Account of Particulars.