subordinate improvements, as he said himself, "followed as corollaries in rapid succession, so that in the course of one or two days the invention was thus far complete in his mind." It cost him ten long weary years of patient speculation and experiment, to carry out the idea, with little hope to buoy him up, for to the last he used to say "his fear was always equal to his hope,"--and with all the cares and embarrassments of his precarious trade to perplex and burden him. Even when he had his working model fairly completed, his worst difficulties--the difficulties which most distressed and harassed the shy, sensitive, and retiring Watt--seemed only to have commenced. To give the invention a fair practical trial required an outlay of at least L1000; and one capitalist, who had agreed to join him in the undertaking, had to give it up through some business losses. Still Watt toiled on, always keeping the great object in view,--earning bread for his family (for he was married by this time), by adding land-surveying to his mechanical labours, and, in short, turning his willing hand to any honest job that offered. He got a patent in 1769, and began building a large engine; but the workmen were new to the task, and when completed, its action was spasmodic and unsatisfactory. "It is a sad thing," he then wrote, "for a man to have his all hanging by a single string. If I had wherewithal to pay for the loss, I don't think I should so much fear a failure; but I cannot bear the thought of other people becoming losers by my scheme, and I have the happy disposition of always painting the worst." And just then, to make matters still more gloomy, he learned that some rascally linen-draper in London was plagiarizing the great invention he had brought forth in such sore and protracted travail. "Of all things in the world," cried poor Watt, sick with hope deferred, and pressed with little carking cares on every side, "there is nothing so foolish as inventing." When nearly giving way to despair, and on the point of abandoning his invention, Watt was fortunate enough to fall in with Matthew Boulton, one of the great manufacturing potentates of Birmingham, an energetic, far-seeing man, who threw himself into the enterprise with all his spirit; and the fortune of the invention was made. An engine, on the new principle, was set up at Soho; and there Boulton and Watt sold, as the former said to Boswell, "what all the world desires to have, POWER;"--the infinite power that animates those mighty engines, which-- "England's arms of conquest are, The trophies of her bloodless war: Brave weapons these. Victorious over wave and soil, With these she sails, she weaves, she tills, Pierces the everlasting hills, And spans the seas."