“The Steam Engine is one of the most curious, and perhaps most useful machines that owe their origin to the discoveries of philosophy; without it many of the mines in Cornwall must long ago have ceased to have been worked; and among other purposes to which it has elsewhere been most advantageously applied, should be mentioned, the supplying of towns with water, the grinding of corn, the turning of the wheels of machines in woollen manufactories, and the blowing of bellows to fuse ores and metals; we have to boast of this grand machine, being invented, as well as perfected, in our own country: Captain Savery is said to have first discovered the method of raising water by the pressure of air, in consequence of the condensation of steam; or at least he was the first person that put any method of this sort into practice: he obtained a patent, in the year 1698, for a machine contrived in the following manner; the air was expelled from a vessel by steam, and the steam condensed by the admission of cold water, which causing a vacuum, the pressure of the atmosphere forced the water to ascend into the steam vessel through a pipe 24 or 26 feet high: by dense steam brought from the boiler, the water in the steam vessel was elevated to the requisite height. This construction, however, did not answer, because very strong vessels were wanted to resist the expansive violence of the steam; an enormous quantity of which was, besides, condensed by coming in contact with the cold water in the steam vessel. The danger of bursting the vessels was avoided soon afterwards by the invention of Messrs. Newcomen and Cawley, of Dartmouth. These gentlemen employed for the steam vessel a hollow cylinder, shut at the bottom and open at the top, and furnished with a piston sliding easily up and down in it, but made tight by oakum or hemp, and covered with water: the piston was suspended by chains from one end of a beam moveable on an axis in the middle of its length; to the other end of this beam hung the pump rods. Some imperfections still remained; but the most important were at length wholly removed by the discoveries of Mr. Watt, and the construction made use of by that gentleman and Mr. Bolton, of Soho, near Birmingham; who obtained a patent for 25 years, in addition to the term granted to Mr. Watt alone, in the year 1768. One of these machines will work a pump of 18 inches in diameter, and upwards of 100 fathoms in height, at the rate of 10 or 12 strokes, of seven feet long each, in one minute. It will raise to the height of 80 feet, in that same space of time, a weight equal to 18,000 pounds; the combined action of 200 horses could not effect more. In Newcomen’s engine this would have required a cylinder 10 feet in diameter; but as, in the new engine, the steam acts, and a vacuum is made, alternately above and below the piston, the power exerted is double to what the same cylinder would otherwise produce; and is farther