But during the centuries of experiments with a "heat-engine," the political world had greatly changed. The British people had succeeded the Dutch as the common-carriers of the world's trade. They had opened up new colonies. They took the raw materials which the colonies produced to England, and there they turned them into finished products, and then they exported the finished goods to the four corners of the world. During the seventeenth century, the people of Georgia and the Carolinas had begun to grow a new shrub which gave a strange sort of woolly substance, the so-called "cotton wool." After this had been plucked, it was sent to England and there the people of Lancastershire wove it into cloth. This weaving was done by hand and in the homes of the workmen. Very soon a number of improvements were made in the process of weaving. In the year 1730, John Kay invented the "fly shuttle." In 1770, James Hargreaves got a patent on his "spinning jenny." Eli Whitney, an American, invented the cotton-gin, which separated the cotton from its seeds, a job which had previously been done by hand at the rate of only a pound a day. Finally Richard Arkwright and the Reverend Edmund Cartwright invented large weaving machines, which were driven by water power. And then, in the eighties of the eighteenth century, just when the Estates General of France had begun those famous meetings which were to revolutionise the political system of Europe, the engines of Watt were arranged in such a way that they could drive the weaving machines of Arkwright, and this created an economic and social revolution which has changed human relationship in almost every part of the world. As soon as the stationary engine had proved a success, the inventors turned their attention to the problem of propelling boats and carts with the help of a mechanical contrivance. Watt himself designed plans for a "steam locomotive," but ere he had perfected his ideas, in the year 1804, a locomotive made by Richard Trevithick carried a load of twenty tons at Pen-y-darran in the Wales mining district. At the same time an American jeweller and portrait-painter by the name of Robert Fulton was in Paris, trying to convince Napoleon that with the use of his submarine boat, the "Nautilus," and his "steam-boat," the French might be able to destroy the naval supremacy of England. Fulton's idea of a steamboat was not original. He had undoubtedly copied it from John Fitch, a mechanical genius of Connecticut whose cleverly constructed steamer had first navigated the Delaware river as early as the year 1787. But Napoleon and his scientific advisers did not believe in the practical possibility of a self-propelled boat, and although the Scotch-built engine of the little craft puffed merrily on the Seine, the great Emperor neglected to avail himself of this formidable weapon which might have given him his revenge for Trafalgar.