GALILEO AND THE NEW PHYSICS 



cumscribing wall; the aggregate pressure may, there- 

 fore, be increased indefinitely by increasing the sur- 

 face. It is this principle, of course, which is utilized 

 in the familiar hydrostatic press. Theoretical expla- 

 nations of the pressure of liquids were supplied a gen- 

 eration or two later by numerous investigators, in- 

 cluding 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 Alex- 

 andrian epoch, had solved the most important prob- 

 lems of hydrostatic equilibrium. Now, however, his 

 experiments were overlooked or forgotten, and Galileo 

 was obliged to make experiments anew, and to com- 

 bat 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 penetra- 

 tion, and that this resistance is instrumental in deter- 

 mining whether a body placed in water will float or 



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