In 1816, on a visit to Greenock, Watt made a voyage in a steamboat to Rothsay and back again. In the course of this experimental trip he pointed out to the engineer of the boat the method of "backing" the engine. With a foot-rule he demonstrated to him what he meant. Not succeeding, however, he at last, under the impulse of the ruling passion (and we must remember he was then eighty), threw off his overcoat, and putting his hand to the engine himself, showed the practical application of his lecture. Previously to this, the "backstroke" of the steamboat engine was either unknown or not generally known. The practice was to stop the engine entirely a considerable time before the vessel reached the point of mooring, in order to allow for the gradual and natural diminution of her speed.
With regard to the application of steam power to locomotion on land, it is remarkable enough that, when Watt's attention was first directed, by his friend Robison, to the steam-engine, "he (Robison) at that time drew out an idea of applying the power to the moving of wheel-carriages." "But the scheme," adds Watt, "was not matured, and was soon abandoned on his going abroad."
In 1769, however, when he heard that a linen-draper, one Moore, had taken out a patent for moving wheel-carriages by steam, he replied: "If linen-draper Moore does not use my engine to drive his chaises, he can't drive them by steam." In the specification of his patent of 1784, he even described the principles and construction of "steam-engines which are applied to give motion to wheel-carriages for removing persons or goods, or other matters, from place to place," and in 1786, Watt himself had a steam-carriage "of some size under hand;" but his most developed plan was to move such carriages "on a hard smooth plane," and there is no evidence to show that he ever anticipated the union of the rail and wheel.
Among Watt's mechanical recreations, soon after the date of the last of his steam-engine patents, were four plans of making lamps, which he describes in a letter to Argand; and for a long time lamps were made at Soho upon his principles, which gave a light surpassing, both in steadiness and brilliancy, anything of the kind that had appeared. About a year after, in 1788, he made "a pretty instrument for determining the specific gravities of liquids," having, he says to Dr. Black, improved on a hint he had taken.
Watt also turned his "idle thoughts" toward the construction of an arithmetical machine, but he does not appear ever to have prosecuted this design further than by mentally considering the manner in which he could make it perform the processes of multiplication and division.
Early in the present century Watt devised, for the Glasgow water-works, to bring pure spring-water across the Clyde, an articulated suction-pipe, with joints formed on the principle of those in a lobster's tail, and so made capable of accommodating itself to all the actual and possible bendings at the bottom of the river. This pipe was, moreover, executed at Soho from his plans, and was found to succeed perfectly.
Watt describes, as his hobby, a machine to copy sculpture, suggested to him by an implement he had seen and admired in Paris in 1802, where it was used for tracing and multiplying the dies of medals. He foresaw the possibility of enlarging its powers so as to make it capable of working even on wood and marble, to do for solid masses and in hard materials what his copying machine of 1782 had already done for drawings and writings impressed upon flat surfaces of paper—to produce, in fact, a perfect fac-simile of the original model. He worked at this machine most assiduously, and his "likeness lathe," as he termed it, was set up in a garret, which, with all its mysterious contents, its tools, and models included, have been carefully preserved as he left them.
It is gratifying to find that the charm of Watt's presence was not dimmed by age. "His friends," says Lord Jeffrey, speaking of a visit which he paid to Scotland when upward of eighty, "in that part of the country never saw him more full of intellectual vigor and colloquial animation, never more delightful or more instructive." It was then also that Sir Walter Scott, meeting him "surrounded by a little band of northern literati," saw and heard what he felt he was never to see or hear again—"the alert, kind, benevolent old man, his talents and fancy overflowing on every subject, with his attention alive to everyone's question his information at everyone's command." Campbell, the poet, who saw him later, in the beginning of 1819 (he was then eighty-three), describes him as so full of anecdote, that he spent one of the most amusing days he had ever had with him. Lord Brougham, later still, in the summer of the same year, found his instructive conversation and his lively and even playful manner unchanged. But in the autumn of this year, on August 19th, he expired tranquilly at his house at Heathfield. He was buried at Handsworth. A tribute to his memory was but tardily rendered by the nation.
Jeffrey and Arago added more elaborate tributes to Watt's genius; and Wordsworth has declared that he looked upon him, considering his magnitude and universality, "as perhaps the most extraordinary man that this country has ever produced." His noblest monument is, however, his own work.[Back to Contents]