But whatever the imitators of Besnier may have accomplished, to the honest smith must be accorded the full credit of their success, and with his simple, but brilliant, record left at flood mark, the tide of progress ebbed back again, while mankind ruminated over the great problem in apparent inactivity. But not for long. The air-pump about this period was given to the world, and chemists were already busy investigating the nature of gases. Cavallo was experimenting on kindred lines, while in our own land the rival geniuses of Priestley and Cavendish were clearing the way to make with respect to the atmosphere the most important discovery yet dreamed of. In recording this dawn of a new era, however, we should certainly not forget how, across the Atlantic, had arisen a Rumford and a Franklin, whose labours were destined to throw an all-important sidelight on the pages of progress which we have now to chronicle. CHAPTER II. THE INVENTION OF THE BALLOON. It was a November night of the year 1782, in the little town of Annonay, near Lyons. Two young men, Stephen and Joseph Montgolfier, the representatives of a firm of paper makers, were sitting together over their parlour fire. While watching the smoke curling up the chimney one propounded an idea by way of a sudden inspiration: "Why shouldn't smoke be made to raise bodies into the air?" The world was waiting for this utterance, which, it would seem, was on the tip of the tongue with many others. Cavendish had already discovered what he designated "inflammable air," though no one had as yet given it its later title of hydrogen gas. Moreover, in treating of this gas--Dr. Black of Edinburgh, as much as fifteen years before the date we have now arrived at, had suggested that it should be made capable of raising a thin bladder in the air. With a shade more of good fortune, or maybe with a modicum more of leisure, the learned Doctor would have won the invention of the balloon for his own country. Cavallo came almost nearer, and actually putting the same idea into practice, had succeeded in the spring of 1782 in making soap bubbles blown with hydrogen gas float upwards. But he had accomplished no more when, as related, in the autumn of the same year the brothers Montgolfier conceived the notion of making bodies "levitate" by the simpler expedient of filling them with smoke.