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know them.” Perhaps the best way of proceeding will be
to give one or two examples of the mode in which men of
seience apply the unintelligent impulse with which Mr.
Mozley credits them, and which shall show by illustration
the surreptitious character of the method by which they
climb from the region of facts to that of laws.

It was known before the sixteenth century that, the end
of an open tube being dipped into water, on drawing an
air-tightpiston up the tube the water follows the piston,
and this fact had been turned to account in the construction.
of the common pump. The effect was explained at the
time by the maxim, “ Nature abhors a vacuum.” It was
not knoWn that there was any limit to the height to which
the water would ascend, until, on one occasion, the garden-
ers of Florence, while attempting to raise the water a very
great elevation, found that the column ceased at a height
of thirty-two feet. Beyond this all the skill of the pump-
maker could not get it to rise. The fact was brought to
the notice of Galileo, and he, soured by a world which had
not treated his science over-kindly, is said to have twitted
the philosophy of the time by remarking that Nature evi-
dently abhorred a vacuum only to a height of thirty-two
feet. But Galileo did not solve the problem. It was taken
up by his pupil Torricelli, who pondered it, and while he
did so various thoughts regarding it arose in his mind. It
occurred to him that the water might be forced up in the
tube by a pressure applied to the surface of the water out-
side. But where, under the actual circumstances, was such
a pressure to be found? After much reflection, it flashed
upon Torricelli that the atmosphere might possibly exert
the pressure; that the impalpable air might possess weight,
and that a column of water thirty-two feet high might be
of the exact weight necessary to hold the pressure of the
atmosphere in equilibrium.

There is much in this process of pondering and its

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