The steam engine familiarly explained and illustrated; with an historical sketch of its invention and progressive improvement; its applications to navigation and railways; with plain maxims for railway speculators. By the Rev. Dionysius Lardner ... With additions and notes by James Renwick ...

48 THE STEAM ENGINE.
the rules of statics, and by science reduced to measure,
weight, and balance, then they bear their load peaceably,
(like good horses,) and thus become of great use to mankind,
particularly for raising water, according to the following
table, which shows the number of pounds that may be raised
1800 times per hour to a height of six inches, by cylinders
half filled with water, as well as the different diameters and
depths of the said cylinders.'"
DENIS PAPIN, 1695.
(29.) Denis Papin, a native of Blois in France, and professor of mathematics at Marbourg, had been engaged about
this period in the contrivance of a machine in which the
atmospheric pressure should be made available as a mecha
nical agent, by creating a partial vacuum in a cylinder under
a piston. His first attempts were directed to the production
of this vacuum by mechanical means, having proposed to
apply a water-wheel to work an air-pump, and so maintain
the degree of rarefaction required. This, however, would
eventually have amounted to nothing more than a mode of
transmitting the power of the water-wheel to another engine,
since the vacuum produced in this way could only give back
the power exerted by the water-wheel diminished by the
friction of the pumps; still this would attain the end first
proposed by Papin, which was merely to transmit the force
of the stream of a river, or a fall of water, to a distant point,
by partially exhausted pipes or tubes. He next, however,
attempted to produce a partial vacuum by the explosion of
gunpowder; but this was found to be insufficient, since so
much air remained in the cylinder under the piston, that at
least half the power due to a vacuum would have been lost.
"I have, therefore," proceeds Papin, "attempted to attain
this end by another method. Since water being converted
into steam by heat acquires the property of elasticity like
air, and may afterward be recondensed so perfectly by cold