THE SEQUENCE OF EVENTS 13 



which is doubled, depends on both pressure and duration of the wave.) 

 The character of pressure waves at great distances from the charge 

 may be affected by other factors, such as attenuation by viscosity 

 effects and refraction by velocity gradients in the water. These effects 

 become appreciable only for such ranges that the wave is of acoustic 

 intensity, and their detailed description belongs more properly to a 

 treatise on underwater sound transmission. 



