bodies at rest led
Stevinus, not unnaturally, to consider the allied subject of the
pressure of liquids. He is to be credited with the explanation of the
so-called hydrostatic paradox. The familiar modern experiment which
illustrates this paradox is made by inserting a long perpendicular tube
of small caliber into the top of a tight barrel. On filling the barrel
and tube with water, it is possible to produce a pressure which will
burst the barrel, though it be a strong one, and though the actual
weight of water in the tube is comparatively insignificant. This
illustrates the fact that the pressure at the bottom of a column of
liquid is proportionate to the height of the column, and not to its
bulk, this being the hydrostatic paradox in question. The explanation
is that an enclosed fluid under pressure exerts an equal force upon all
parts of the circumscribing wall; the aggregate pressure may, therefore,
be increased indefinitely by increasing the surface. It is this
principle, of course, which is utilized in the familiar hydrostatic
press. Theoretical explanations of the pressure of liquids were supplied
a generation or two later by numerous investigators, including Newton,
but the practical refoundation of the science of hydrostatics in modern
times dates from the experiments of Stevinus.

GALILEO AND THE EQUILIBRIUM OF FLUIDS

Experiments of an allied character, having to do with the equilibrium of
fluids, exercised the ingenuity of Galileo. Some of his most interesting
experiments have to do with the subject of floating bodies. It will be
recalled that Archimedes, away back in the Alexandrian epoch, had solved
the most important problems of hydrostatic equilibrium. Now, however,
his experiments were overlooked or forgotten, and Galileo was obliged
to make experiments anew, and to combat fallacious views that ought long
since to have been abandoned. Perhaps the most illuminative view of
the spirit of the times can be gained by quoting at length a paper of
Galileo's, in which he details his own experiments with floating bodies
and controverts the views of his opponents. The paper has further
value as illustrating Galileo's methods both as experimenter and as
speculative reasoner.

The current view, which Galileo here undertakes to refute, asserts that
water offers resistance to penetration, and that this resistance is
instrumental in determining whether a body placed in water will float
or sink. Galileo contends t