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Secondly, the tensile wave reflected from the free water surface will imply physically that 

 the water near the piston is being pulled away from the latter by the water near the surface. If, 

 therefore, cavitation occurs due to this tensile wave, the water on the surface side of such 

 cavitation ceases to exert any pull on the water near the piston and the latter water will thus 

 more easily move in the direction of the piston. Expressed otherwise the assumption of no 

 cavitation used in deriving equation (13) for a may imply quite large net tensions in the water 

 near the piston and it is difficult to see how such tensions can arrive near the piston since 

 they will proOaDly have caused prior cavitation in the water near the surface. * It would therefore 

 seem that nejlect of cavitation in calculating a as in equation (l3) will Imply if anything an 

 overcorrection for surface fjffect. 



