This event created a sensation not only in France but over the whole of Europe. In Paris, particularly, the effect on all classes was so great that they determined to have the experiment repeated, set a subscription on foot, and appointed a scientific man named Charles, and two brothers of the name of Robert, to construct a balloon. This they did, but instead of applying the Montgolfier motive power--heated air--they used hydrogen gas, procured by the action of diluted sulphuric acid upon iron filings. Their balloon, which was made of thin silk, varnished with a solution of elastic gum, was a much nearer approach to the balloon of modern days than that of Montgolfier. It was a great success; it rose and remained suspended at a height of 100 feet, in which state it was conveyed with acclamation to the Place des Victoires, where it rested and underwent some repairs. At midnight it was conveyed in solemn procession by torchlight, and guarded by a detachment of horse, to the Champ de Mars, where, on the following day, the whole world of Paris turned out to witness another ascent. The balloon went up to the sound of cannon, and in two minutes reached a height of 3000 feet, when it was lost for a time in a dark cloud, but speedily reappeared still higher. After a flight of fifteen miles, performed in three-quarters of an hour, it sunk to the ground in a field near Ecouen, where it was secured by the peasants. The Parisians now appeared to become balloon-mad. The Royal Academy of Sciences invited Joseph Montgolfier to repeat his experiments, and another balloon was prepared by him of coarse linen with a paper lining, which, however, was destroyed by incessant and violent rain before it could be tried. Undeterred by this, another was constructed by him, which ascended from Versailles on the 19th of September 1783. This balloon deserves peculiar notice as being the first which carried up living creatures. A sheep, a cockerel, and a duck, were the first aeronauts! They ascended to a height of about 1500 feet; remained suspended for a time, and descended some two miles off in perfect safety--indeed we may say in perfect comfort, for the sheep was discovered to be quietly feeding when it returned to the earth! The practicability of ballooning being now fairly established, men soon began to venture their own persons in the frail cars. A young and enthusiastic naturalist named Rozier leaped into the car of another of Montgolfier's balloons soon after this, and ascended in safety to an elevation of about 300 feet, but on this occasion the balloon was held down by ropes. The ice, however, was broken, and bolder attempts quickly followed. CHAPTER THREE. EARLY ATTEMPTS AT AERIAL NAVIGATION. The first free and unfettered balloon voyage was performed very soon after the event mentioned at the end of the last chapter. It was a daring attempt, and attended with great danger.