Many more cases could be cited. Some ended disastrously; others, because of the apathy, distrust, ignorance, and superstition of the people, were lost sight of again; while some, perhaps the most practical ones and of which we find many indications in old writings, were never made known for selfish reasons. Such has been the fate of this--one of the most interesting problems--almost up to the present time. We were, perhaps, not prepared sufficiently, to receive the great boon. We had to have the printing press, steam, and electricity first, before we could attempt this next great step towards a higher civilization. III.--DISCOVERY OF THE BALLOON. Although it is well understood now by most scientific men, that the principles upon which ballooning rests, will scarcely form any part in the solution of the problem of ærial navigation; yet, when, in 1782, the brothers, Mongolfier, in France, made the first successful experiments with small paper balloons, filled with heated air, it was thought that the key to that wonderful art had been found; many applied themselves to its improvement; and the next year already saw gas balloons on a much larger scale. The first passengers, who had the honor of being sent up into the realms of space, were a sheep, a cock and a duck; and as their safe descent proved highly satisfactory, the well-known French savan, Pilatre de Rozier, tried the same experiment shortly afterwards with great success, reaching a hight of nearly two miles. The glowing description of his experience raised the excitement of all classes to fever heat. Numerous day and night ascensions were made by diplomats, distinguished naturalists, professors of note, scientific women and gymnastic aspirants, and their journeys soon became more daring and extended to wider fields. IV.--NOTED AIR VOYAGES. Blanchard, the supposed inventor of the parachute, with the American, Dr. Jeffries, were the first to cross the channel from England to France. M. Charles, the inventor of the gas balloon, and one of the earliest and most enthusiastic advocates of ærostation, made extensive voyages. Madame Thible, of Lyons, was the first of her sex who trusted herself to the elastic element. Crosbie, who passed over the sea from Ireland to England, came near losing his life; for, the balloon, being struck with great force by an adverse current of air, and most of the gas escaping, tore over the raging waters at a fearful speed, until the courageous man was rescued, near the English coast, by a ship happening in his way. But the view which he had enjoyed, seeing both countries at once, was sublime beyond description, and compensated him for all the danger. He had been at such a hight that, although the July sun melted everything below, his ink was a lump of ice, and the quicksilver in the instruments had sunk almost out of sight.