183 



NOTATION 



Radius of the spherical cavity- 

 Value at the peak of compression 



Value at the point where the gas pressure equals the external 

 pressure pg 



^ Value at the limit of the first expansion 



Volume of the cavity = ^Trieyj 



Ratio of specific heat at constant pressure to that at constant 

 volume = ^ A for air, or 1 .3 for TNT gas 



p Mass density, ordinarily in dynamical or ips units 



r Radial distance from the center of the bubble to a station in 

 the water 



t Symbol for time in general 



T Period or duration of the motion from minimum to minimum of R 



Tj Value of T when R does not depart widely from Rq 



p Symbol for pressure in general 



p^ Any pressure expressed in atmospheres 



Pg Hydrostatic pressure; the pressure on the cavity before the ex- 

 plosion, or the pressure in the water at a great distance from 

 the charge 



Pg Pressure in the gas, assumed to be uniform 



Pmax Value at the peak of compression 



V Symbol for particle velocity, zero at great distance from the 

 charge 



Vg Velocity of the gas, equal to that in the water at the boundary 



c Velocity of sound in homogeneous water 



C Speed of sound in water containing bubbles 



Q The whole energy radiated in one cycle of pulsation, concentrated 



in the phase of peak pressure 



E Energy of oscillation, represented by the kinetic energy when 



R = Rq, also by the work done against p^ (less the small work 

 of the gas) in expanding from R^ to i?2 



/ Impulse or time-integral of a pressure 



/ Fraction of the space occupied by bubbles in water 



