Notwithstanding his rebuff by the Navy Surveyor, Savery proceeded to fit up a small yacht with his engine, and tried an experiment with it on the Thames, in sight of many thousands of spectators. The experiment was, in his opinion, entirely successful. The yacht, manned by eight sailors working the capstan, passed a ketch with all its sails spread, as well as other vessels. “All people,” said Savery, “seemed to like the demonstration of the use of my engine, the public newspapers speaking very largely of it, yet all to no purpose.” Savery had already expended 200_l._ in his experiments on the paddle-wheel boat, and was not disposed to go any further, now that Government had decided not to take up the invention. Indeed, its practical utility was doubtful. The power of the wind was, after all, better than hand-labour for working large ships; and it continued to maintain its superiority until the steam-engine was brought to perfection. It is curious that it should not have occurred to Savery, who invented both a paddle-wheel boat and a steam-engine, to combine the two in one machine; but he was probably sick of the former invention, which had given him so much vexation and annoyance, and gave it up in disgust, leaving it to Papin, who saw both his inventions at work, to hit upon the grand idea of combining the two in a steam-vessel,--the only machine capable of effectually and satisfactorily rowing ships in a calm, or against wind and tide. It is probable that Savery was led to enter upon his next and most important invention by the circumstance of his having been brought up in the neighbourhood of the mining districts, and being well aware of the great difficulty experienced by the miners in keeping their pits clear of water, to enable them to proceed with their underground operations. The early tin-mining of Cornwall was for the most part what was called “stream-work,” being confined mainly to washing and collecting the diluvial deposits of the ore. Mines usually grew out of these stream-works; the ground was laid open at the back of the lodes, and the ore was dug out as from a quarry. Some of these old openings, called “coffins,” are still to be met with in different parts of Cornwall. The miners did not venture much below the surface, for fear of the water, by which they were constantly liable to be drowned out. But as the upper strata became exhausted, they were tempted to go deeper in search of the richer ores. Shafts were sunk to the lodes, and they were followed underground. Then it was that the difficulty of water had to be encountered and overcome; for unless it could be got rid of, the deeper ores of Cornwall were as so much buried treasure. When the mines were of no great depth, it was possible to bale out the water by hand-buckets. But this expedient was soon exhausted; and the power of horses was then employed to draw the buckets. Where the lodes ran along a hill-side, it