It would not be unreasonable to inquire how it can be necessary now to write an account of Richard Trevithick, seeing that only nine or ten years ago two elaborate volumes on the subject were published by his son Francis.[141] But, apart from the propriety of including so remarkable a man in the _fasciculus_ of our Cornish worthies, it may be observed that the very amplitude of the 'Life' to which I have referred renders it inaccessible to the general reader; and moreover it is (as the talented civil engineer who wrote that valuable and interesting work himself observes), almost as much a technical history of the development of the steam-engine as a memoir of him who was so intimately associated with its rise and progress. Our purpose is biography; and, unless I am grievously mistaken, this aspect of the subject will be found full of interest. The steam pumping-engine is to a mine what the heart is to a man: were its action to cease, or to be inefficiently performed, the mine would be flooded, and would cease to be. It is therefore not to be wondered at if, so soon as men ceased to find the precious ores in granules on the surface, washed down by mountain streams from the denuded veins which seam the hillsides, attention should be directed towards finding the coveted treasures in the bowels of the earth itself. But here a difficulty met the searchers. As they sunk their pits they often tapped the sources of streams, which, gushing out, at once put an end to their quest. Rude expedients were at first employed to remedy this; wooden pumps, worked by the hand, and such-like feeble attempts at getting over the difficulty. But it was not until 1702 that, according to some accounts, the first steam pumping-engine was erected in Cornwall, by Savery. Newcomen, whose name will always be honourably associated with the improvement of this invaluable machine, very soon was able to increase its efficiency, and erected one of his best engines in 1720, at the mine-works of Ludgvan-lez, near Penzance. By 1756 there were _several_ steam-engines at work in Cornwall; but their defects, especially as regards their low power, and their extravagant consumption of coal, were inconveniently felt. It was at length perceived that the solution of the difficulty lay in a diminution of the size of the boiler, and an increase in the elastic force of the steam; and for the accomplishment of these objects we are mainly indebted to the subject of this memoir, as well as, in some degree, also to his father. The circumstances which surrounded them were by no means encouraging. Coal, of course, had to be imported, and also iron plates for the boilers; and the latter it was necessary, in those days, to make of small size, on account of the indifferent condition of the Cornish roads, along which (as no heavy wheeled-traffic was practicable), the burdens had to be transported from the ports to the mines, and _vice versa_, on the backs of mules.