Photo source: Wikimedia Commons, Carl Friedrich Breda
James Watt (1736-1819) was a Scottish inventor best known for his contributions to the stream engine. Economist Jeremy Rifkin said,
"James Watt patented his steam engine on the eve of the American Revolution, consummating a relationship between coal and the new Promethean spirit of the age, and humanity made its first tentative steps into an industrial way of life that would, over the next two centuries, forever change the world." (Quoted in The Hydrogen Economy)Chemist Humphry Davy said,
"Those who consider James Watt only as great practical mechanic form a very erroneous idea of his character: he was equally distinguished as a natural philosopher and a chemist, and his inventions demonstrate his profound knowledge of those sciences, and that peculiar characteristic of genius, the union of them for practical application." (Quoted in Proceedings of the Public Meeting held at Freemasons Hall, 1824)The rest of this post is some quotes from Watt.
Thinking
"I can think of nothing else than this machine." (Letter to Dr. Lind, 1765)
"I had gone on a walk on a fine Sabbath afternoon... I was thinking upon the engine at the time, and had gone as far as the herd's house, when the idea came into my mind that as steam was an elastic body it would rush into a vacuum, and if a communication were made between the cylinder and an exhausted vessel it would rush into it, and might be there condensed without cooling the cylinder." (Quoted in Reminiscences of James Watt by Robert Hart)
"When once the idea of the separate condensation was started, all these improvements followed as corollaries in quick succession, so that in the course of one or two days the invention was thus far complete in my mind, and I immediately set about an experiment to verify it practically." (Notes on Professor Robison's Dissertation on Steam-engines, 1769)
Steam engine
"It now appeared that the cylinder of the model, being of brass, would conduct heat much better than the cast-iron cylinders of larger engines (generally covered on the inside with a stony crust), and that considerable advantage could be gained by making the cylinders of some substance that would receive and give out heat slowly." (Notes on Professor Robison's Dissertation on Steam-engines, 1769)
"I perceived that, in order to make the best use of steam, it was necessary - first, that the cylinder should be maintained always as hot as hot as steam which entered it; and, secondly, that when the steam was condensed, the water of which it was composed, and then injection itself, should be cooled down to 100 degrees, or lower, where that was possible." (Notes on Professor Robison's Dissertation on Steam-engines, 1769)
"There still remained another source of the destruction of steam, the cooling of the cylinder by the external air, which would produce an internal condensation whenever the steam entered it, and which would be repeated every stroke; this I proposed to remedy by an external cylinder, containing steam, surrounded by another of wood, or of some other substance which would conduct heat slowly." (Notes on Professor Robison's Dissertation on Steam-engines, 1769)
