Mr. Watt gained a patent for his engine in 1768, but the further persecution of his designs were delayed by other avocations till 1775, when in conjunction with Mr. Boulton of Soho near Birmingham, numerous experiments were made on a large scale by their united ingenuity, and great improvements added to the machinery, and an act of parliament obtained for the prolongation of their patent for twenty-five years, they have since that time drained many of the deep mines in Cornwall, which but for the happy union of such genius must immediately have ceased to work. One of these engines works a pump of eighteen inches diameter, and upwards of 100 fathom or 600 feet high, at the rate of ten to twelve strokes of seven feet long each, in a minute, and that with one fifth part of the coals which a common engine would have taken to do the same work. The power of this engine may be easier comprehended by saying that it raised a weight equal to 81000 pounds 80 feet high in a minute, which is equal to the combined action of 200 good horses. In Newcomen's engine this would have required a cylinder of the enormous diameter of 120 inches or ten feet, but as in this engine of Mr. Watt and Mr. Boulton 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 otherways produce, and is further augmented by an inequality in the length of the two ends of the lever. These gentlemen have also by other contrivances applied their engines to the turning of mills for almost every purpose, of which that great pile of machinery the Albion Mill is a well known instance. Forges, slitting mills, and other great works are erected where nature has furnished no running water, and future times may boast that this grand and useful engine was invented and perfected in our own country. Since the above article went to the press the Albion Mill is no more; it is supposed to have been set on fire by interested or malicious incendaries, and is burnt to the ground. Whence London has lost the credit and the advantage of possessing the most powerful machine in the world! NOTE XII.--FROST. _In phalanx firm the fiend of Frost assail._ CANTO I. l. 439.