119 



- u - 



to consider the effect of the long continued, low preesure, kinetic »ave as well as the pressure 

 wave. 



It is worth noticinij that shot 107 was made at depth 3 feet and horizontal distance 1* feet, 

 so that the positive pressure wave would Oe cut off 0.5 milliseconds after the explosion. This 

 would prevent water from the back s;jrface of the cavitation formed oehind the plate when the pressure 

 falls to zero from Peing discharged and exerting further pressure on the plate, so that in this 

 case a theory which assumes that no further pressure is exerted after the plate has become detached 

 from the water may oe applicable, 



Cases *«. US and 59 in which small charges were placed close to the plate are interesting 

 because the effect of the kinetic wave might be expected to be greater relative to the pressure 

 wave than in the other cases. The way in which the value of h /z is much more nearly that which 

 corresponds with a static pressure than the higher values associateJ with Impulsive pressures is 

 a striking feature of Figure ». This seems to be an indication that in this case the main cause 

 of damage may be the kinetic wave ralner than the pressure wave. 



References . 



(1) Lode, Zeits. f. Physik, 36, page 913, 1926. 



(2) Taylor and Quinney, "The plastic distortion of metals," Phil., Trans., A, 230. 



(3) See equation («7). 

 (U) See equation (3'). 



(5) "The pressure and impulse of submarine explosion waves on plates".. 



(6) See equation (27) of the :ibove mentioned report, 



(7) X is here expressed in centimetres so that M^^/X shall be in C.G.S. units. 



(9) Equation (lo) of report "Vertical motion of a spherical bubble and the pressure 

 surrounding it". 



(9) Sir R. Roberton and W.E. Garner, Proc. Roy. Soc., A, 103, 1923. 



