"I have sometimes wondered," said Uncle Fritz, "whether our American word 'car' where the English say 'wagon' did not come from the 'rapid car' of Dr. Darwin. Read on, Fanchon." And he put his finger on the lines which Fanchon read:-- "Or on wide waving wings, expanded, bear The flying chariot through the fields of air." "Monsieur ----, the French gentleman, tried a light steam-engine for the propulsion of a balloon in 1872; but it does not seem to have had power enough. Messrs. Renard and Krebs, in their successful flight of August last, used an electric battery. "But we are getting away from Fulton, who is really the first who drove the 'slow barge,' and indeed made it a very fast one." "Did you know him?" asked Emma Fortinbras, whose ideas of chronology are very vague. "Oh, no!" said Uncle Fritz; "he died young and before my time. But I did know a personal companion and friend, nay, a bedfellow of his, Benjamin Church, who was with him in Paris at one of the crises of his life. Fulton had a little steamboat on the river Seine, as I said just now; and he had made interest with Napoleon to have it examined by a scientific committee. Steam power was exactly what Napoleon wanted, to take his great army across from Boulogne to England. The day came for the great experiment. Church and Fulton slept, the night before, in the same bed in their humble lodgings in Paris. At daybreak a messenger waked them. He had come from the river to say that the weight of boiler and machinery had been too much for the little boat, that her timbers had given way, and that the whole had sunk to the bottom of the river. But for this misfortune, the successful steamboat would have sailed upon the Seine, and, for aught I know, Napoleon's grandchildren would now be emperors of England." Until Watt had completed the structure of the double-acting condensing-engine, the application of steam to any but the single object of pumping water had been almost impracticable. It was not enough, in order to render it applicable to general purposes, that the condensation of the water should take place in a separate vessel, and that steam itself should be used, instead of atmospheric pressure, as the moving power; but it was also necessary that the steam should act as well during the ascent as during the descent of the piston. Before steam could be used in moving paddle-wheels, it was in addition necessary that a ready and convenient mode of making the motion of the piston continuous and rotary, should be discovered. All these improvements upon the original form of the steam-engine are due to Watt, and he did not complete their perfect combination before the year 1786.