AMERICAN INSTITUTE. 511 



entertain the idea of navigating the air by the new method. The balloons 

 first used by the brothers Montgolfier consisted of a spherical bag of linen, 

 buttoned together. This was suspended on cross poles, and the air within 

 rarified by a fire of wool and straw kindled beneath ; but the rarified air 

 soon escaped through the pores of the linen, and the balloon, in conse- 

 quence, fell to the ground. This difilculty was afterwards obviated by 

 covering and lining the balloon with varnished paper, while the fire was 

 kindled in a vessel, suspended below, and increased or diminished as the 

 navigator desired to mount or descend. 



The first public balloon ascension was made from Annonay on the 5tb of 

 June, 1783. The balloon rose to the height of a mile, and floated along for 

 ten minutes, then losing its buoyancy, fell to the ground. 



The success of this experiment created a universal sensation throughout 

 Europe, and was repeated at once in France and other countries. Euler 

 employed his dying moments in dictating an application of his favorite 

 analysis to determine the ascending motion of a balloon. Other experi- 

 ments were made on a larger scale ; and on the 20th of September, 1783, 

 a large balloon, filled with rarified air, or fire balloon, as those of the 

 Montgolfier construction came to be called, was sent up from Versailles, 

 under the direction of Joseph Montgolfier, in the presence of the king, 

 queen, and court, containing a sheep, a cock, and a goat, the first aerial 

 navigators, who came down in safety eight minutes after, two miles from 

 the place of their ascension. 



The first human aeronaut was Pilatre de Rozier, a young naturalist, who, 

 after a trial trip alone in a balloon, secured by cords, took flight over the 

 roofs of Paris, on the 15th of October, 1783, with the Marquis de Armange, 

 and alighted, after a journey of twenty-five minutes duration, six miles 

 from the point of starting. 



Just before this time, experiments had been made by MM. Charles and 

 Robert, in the construction of balloons of silk, covered with caoutchouc 

 varnish, and inflated with hydrogen gas, generated by the action of sulphuric 

 acid upon iron filings ; and, on the 1st of December, 1783, the two experi- 

 menters ascended in a balloon of this construction, from the Tuilerics, and 

 alighted, aa hour and three quarters afterwards, twenty-five mil-es from 

 Paris. 



The first balloon, in England, was launched on the 25th of November, 

 1783, under the direction of Count Zambeccari ; and the first ascent made 

 on the 15th of September, 1784, by Vincentio Lunardi. During the fol- 

 lowing year, Mr. Blanchard and Dr. JeftVies were the first to cross the 

 British Channel. 



Balloon ascensions now became things of frequent occurrence, and the 

 navigators turned their attention to means whereby to propel and steer 

 them, yet without much eff'ect. Guytou Morveau made use of oars, which 

 he claiuied to be productive of some results ; yet these were soon broken 

 by resistance, and were insufficient to guide the machine. Sails were tried ; 

 but it was found that these, so effective when applied to a vessel whose 



