Their first balloon, made of paper, reverted to the hot-air principle; they lighted a fire of wool and wet straw under the balloon--and as a matter of course the balloon took fire after very little experiment; thereupon they constructed a second, having a capacity of 700 cubic feet, and this rose to a height of over 1,000 feet. Such a success gave them confidence, and they gave their first public exhibition on June 5th, 1783, with a balloon constructed of paper and of a circumference of 112 feet. A fire was lighted under this balloon, which, after rising to a height of 1,000 feet, descended through the cooling of the air inside a matter of ten minutes. At this the Académie des Sciences invited the brothers to conduct experiments in Paris. The Mongolfiers were undoubtedly first to send up balloons, but other experimenters were not far behind them, and before they could get to Paris in response to their invitation, Charles, a prominent physicist of those days, had constructed a balloon of silk, which he proofed against escape of gas with rubber--the Roberts had just succeeded in dissolving this substance to permit of making a suitable coating for the silk. With a quarter of a ton of sulphuric acid, and half a ton of iron filings and turnings, sufficient hydrogen was generated in four days to fill Charles’s balloon, which went up on August 29th, 1783. Although the day was wet, Paris turned out to the number of over 300,000 in the Champs de Mars, and cannon were fired to announce the ascent of the balloon. This, rising very rapidly, disappeared amid the rain clouds, but, probably bursting through no outlet being provided to compensate for the escape of gas, fell soon in the neighbourhood of Paris. Here peasants, ascribing evil supernatural influence to the fall of such a thing from nowhere, went at it with the implements of their craft--forks, hoes, and the like--and maltreated it severely, finally attaching it to a horse’s tail and dragging it about until it was mere rag and scrap. Meanwhile, Joseph Mongolfier, having come to Paris, set about the construction of a balloon out of linen; this was in three diverse sections, the top being a cone 30 feet in depth, the middle a cylinder 42 feet in diameter by 26 feet in depth, and the bottom another cone 20 feet in depth from junction with the cylindrical portion to its point. The balloon was both lined and covered with paper, decorated in blue and gold. Before ever an ascent could be attempted this ambitious balloon was caught in a heavy rainstorm which reduced its paper covering to pulp and tore the linen at its seams, so that a supervening strong wind tore the whole thing to shreds.