512 -8- 



(3) The sign of the shape change agrees with that predicted by Temperley's theory, Out the 

 change takes place considerably earlier than in the theory. A reintegration of Temperley's equation 

 using the observed velocity-time curve reduces this discrepancy somewhat. 



(u) The downward displacement agrees reasonably well with the theory, but is somewhat less 

 at the first minimum than the predicted value. The observed maximum velocity of 185 ft. /sec. falls 

 consideraoly short of the theoretical value of 890 ft. /sec. 



(5) This failure to reach the high velocity predicted may be partly due to turbulence, but 

 may also be due to the flattening of the bubble. 



(6) The vertical tiomentum in the water appears to te approximately conserved up to the 

 minimum if it is assumed that the effective mass of water moving with the bubble is one half that 

 displaced by a sphere of radius equal to the maximum horizontal radius of the flattened bubble. 



(7) The vertical kinetic energy in the water at the minimum is estinrated to be about it 

 of the total energy of the motion, in contrast to the theoretical value of 19J. 



(8) The energy in the gas at the minimum is estimated at em of the total initial energy 

 of the mot ion, 



(9) There Is an indication of a "wake" or region of disturbed water in the rear of the 

 downward moving bubble when near its minimum size. 



(10) The bubble remains coherent for at least two complete oscillations. 



Appendix 



