It was in 1783 that Montgolfier conceived the idea of utilizing the lifting power of hot air and invited the Assembly of Vivarais to watch an exhibition of his invention, when a balloon, 10 feet in circumference, rose to a height of 6,000 feet in under ten minutes. This was followed by a demonstration before Louis XVI at Versailles, when a balloon carrying a sheep, a cock, and a duck, rose 1,500 feet and descended safely. And on November 21st of the same year Pilatre de Rozier, accompanied by the Marquis d'Arlande, made the first human ascent, in the "Reveillon," travelling 5 miles over Paris in twenty minutes. England, it is not surprising to learn, was behind with the invention, but on November 25th, 1783, Count Francesco Zambeccari sent up from Moorfields a small oilskin hydrogen balloon which fell at Petworth; and in August of 1784 James Tytler ascended at Edinburgh in a fire balloon, thus achieving the first ascent in Great Britain. In the same year Lunardi came to London and ballooning became the rage. It was an Englishman, Dr. Jefferies, who accompanied Blanchard in the first cross-Channel flight on January 7th, 1785. Fashionable society soon turned to pursuits other than watching balloon ascents, however, and the joys of the air were confined to a few adventurous spirits, such as Green and Holland, who first substituted coal gas for hydrogen and in 1836 made a voyage of 500 miles from Vauxhall Gardens to Weilburg in Nassau, and James Glaisher, who in the middle of the century began to make meteorological observations from balloons, claiming on one occasion, in 1862, to have reached the great height of 7 miles. FIRST EXPERIMENTS IN GLIDERS AND AEROPLANES. The world seemed content to have achieved the balloon, but there were a few men who realized that the air had not been conquered, and who believed that success could only be attained by the scientific study and practice of gliding. Prominent among these, Sir George Cayley, in 1809, published a paper on the Navigation of the Air, and forecasted the modern aeroplane, and the action of the air on wings. In 1848 Henson and Stringfellow, the latter being the inventive genius, designed and produced a small model aeroplane--the first power-driven machine which actually flew. It is now in the Smithsonian Institute at Washington. Of greater practical value were the gliding experiments by Otto Lilienthal, of Berlin, and Percy Pilcher, an Englishman, at the end of the last century. Both these men met their death in the cause of aviation. Another step forward was made by Laurence Hargrave, an Australian, who invented the box and soaring kite and eighteen machines which flew.