In mine of yesterday, I promis’d to give you an Account of Messrs. Charles and Robert’s Experiment, which was to have been made as this Day, and at which I intended to be present. Being a little indispos’d, and the Air cool, and the Ground damp, I declin’d going into the Garden of the Tuilleries where the Balloon was plac’d, not knowing how long I might be oblig’d to wait there before it was ready to depart; and chose to stay in my Carriage near the Statue of Louis XV. from whence I could well see it rise, and have an extensive View of the Region of Air thro’ which, as the Wind sat, it was likely to pass. The Morning was foggy, but about One aClock, the Air became tolerably clear, to the great Satisfaction of the Spectators, who were infinite, Notice having been given of the intended Experiment several Days before in the Papers, so that all Paris was out, either about the Tuilleries, or the Quays and Bridges, in the Fields, the Shtreets, at the Windows, or on the Tops of Houses, besides the Inhabitants of all the Towns and Villages of the Environs. Never before was a philosophical Experiment so magnificently attended. Some guns were fired to give Notice, that the Departures of the great Balloon was near, and a small one was discharg’d which went to an amazing Height, there being but little Wind to make it deviate from its perpendicular Course, and, at length the Sight of it was lost. Means were used, I am told, to prevent the great Balloon’s rising so high as might indanger its Bursting. Several Bags of Sand were taken on board before the Cord that held it down was cut; and the whole Weight being then too much to be lifted, such a Quantity was discharg’d as to permit its Rising slowly. Thus it would sooner arive at that Region where it would be in Equilibrio with the surrounding Air, and by discharging more Sand afterwards, it might go higher if desired. Between One and Two o Clock, all Eyes were gratified with seeing it rise majestically from among the Tress, and ascend gradually above the Buildings a most beautiful Spectable! When it was about 200 feet high, the brave Adventurers held out and wav’d a little white Pennant, on both Sides their Carr, to salute the Spectators, who return’d loud Claps of Applause. The Wind was very little, so that the Object, tho’ moving to the Northward, continued long in View; and it was a great while before the admiring People began to disperse. The Persons embark’d were Mr. Charles, Professor of Experimental Philosophy, and a zealous Promoter of that Science, and One of the Messieurs Robert, the very ingenious Constructors of the Machine. When it arriv’d at its height, which I suppose might be 3 or 400 Toises, it appear’d to have only horisontal Motion. I had a Pocket Glass, with which I follow’d it, till I lost Sight, first of the Men, then of the Car, and when I last saw the Balloon, it appear’d no bigger than a Walnut. I write this at 7 in the Evening. What became of them is not yet known here. I hope they descended by Day-light, so as to see and avoid falling among Trees or on Houses, and that the Experiment was compleated without any mischievous Accident which the Novelty of it and the want of Experience might well occasion. I am the more anxious for the Event, because I am not well inform’d of the Means provided for letting themselves gently down, and the Loss of these very ingenious Men, would not only be a Discouragement to the Progress of the Art, but be a sensible Loss to Science and Society.

I shall inclose one of the Tickets of Admission, on which the Globe was represented, as originally intended, but is altered by the Pen to show its real State when it went off. When the Tickets were engraved, the Car was to have been hung to the Neck of the Globe, as represented by a little Drawing I have made in the Corner A. I suppose it may have been an Apprehension of Danger in straining too much the Balloon or tearing the Silk, that induc’d the Constructors to throw a Net over it, fix’d to a Hoop which went round its Middle, and to hang the Car to that Hoop, as you see in Fig. B.

Tuesday Morning, Dec 2. I am releiv’d from my Anxiety, by hearing that the Adventurers descended well near l’Isle Adam, before Sunset. This Place is near 7 Leagues from Paris. Had the Wind blown fresh, they might have gone much farther.

If I receive any farther Particulars of Importance I shall communicate them hereafter. With great Esteem, I am, Dear Sir, Your most obedient and most humble Servant