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The Jeffersonian cyclopedia;

a comprehensive collection of the views of Thomas Jefferson classified and arranged in alphabetical order under nine thousand titles relating to government, politics, law, education, political economy, finance, science, art, literature, religious freedom, morals, etc.;

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8180. STEAM, Horse power vs.—
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8180. STEAM, Horse power vs.—

say you have not been able to learn whether,
in the new mills in London, steam is the immediate
mover of the machinery, or raises
water to move it. It is the immediate mover.
The power of this agent, though long known, is
but now beginning to be applied to the various
purposes of which it is susceptible. * * * I have had a conversation on the subject * * * with the famous Boulton to whom those mills
belong. * * * He compares the effect of
steam with that of horses in the following
manner: Six horses, aided with the most advantageous
combination of the mechanical powers
hitherto tried, will grind six bushels of flour
in an hour; at the end of which time they are
all in a foam, and must rest. They can work
thus six hours in the twenty-four, grinding thirty-six
bushels of flour, which is six to each
horse, for the twenty-four hours. His steam
mill in London consumes one hundred and
twenty bushels of coal in twenty-four hours,
turns ten pair of stones, which grind eight
bushels of flour an hour each, which is nineteen
hundred and twenty bushels in the twenty-four
hours. This makes a peck and a half of
coal perform exactly as much as a horse in one
day can perform. [468]
To Charles Thomson. Washington ed. ii, 67. Ford ed., iv, 337.
(P. 1786)


Parton, in his Life of Jefferson, p. 303, says: “It
was Jefferson who first sent to America the most
important piece of mechanical intelligence that pen
ever recorded,—the success of the Watt steam engine,
by means of which `a peck and a half of coal
performs as much work as a horse in a day'. He
conversed at Paris with Boulton, who was Watts's
partner in the manufacture of the engines, and
learned from his lips this astounding fact. But it
did not astound him in the least. He mentions it
quietly in the postcript of a long letter; for no man
yet foresaw the revolution in all human affairs
which that invention was to effect.”—Editor.