RECOMMENDATIONS 



1. Conduct operational research to determine the useful- 

 ness and limitations of both sound sources in the tactical 

 applications suggested above. 



2. Continue the study and experiments described here, 

 with a view to extending the potentialities of the two sound 

 sources, and improving the materials and techniques 

 involved in manufacturing and operating them. 



3. Consider the feasibility of resuming study of the 

 other sound sources partially explored and briefly reported 

 here. 



ADMINISTRATIVE INFORMATION 



Work was performed under AS 02101, S-FOOl 03 04, 

 Task 8050 (NEL L3-3) by members of the Acoustics 

 Division. The report covers work from June 1956 to 

 September 1960 and was approved for publication 17 October 

 1960. 



The author appreciates the assistance of F. D. Parker, 

 Group Leader, and of M. R. Markland, C. C. Dietrich, 

 J. Lyons, and P. Olszanecky. The work of John Pflaum in 

 obtaining the high-speed underwater photographs; of E. RoUe, 

 who developed many combinations of compounds for trial as 

 dielectric material; and of R. J. Bolam, who assisted in the 

 interpretation of the data, is also gratefully acknowledged. 



