Preface 



The -content and purpose of this book are largely the result of re- 

 search on underwater explosions carried out by many groups in the 

 years 1941-46. Much of the present knowledge and understanding of 

 this field was acquired because of the demands of these war years and 

 the few available discussions of the subject have become inadequate or 

 obsolete. This book is an attempt to supply a reasonably comprehen- 

 sive account which will be of use both to workers in the field of under- 

 water explosions and to others interested in the basic physical processes 

 involved. 



Because of the fact that hydrodynamics is a relatively unfamiliar 

 branch of physical science, some attention has been given to develop- 

 ment of necessary hydrodynamical relations from first principles. The 

 discussions of theoretical and experimental methods have been de- 

 veloped with the hope both of making clear the value and limitations of 

 the results obtained and of making available material of possible inter- 

 est in other fields. 



The theoretical predictions and experimental data presented have 

 been selected primarily on a basis of fundamental interest rather than 

 military importance; this criterion was felt desirable in most cases and 

 Avas made necessary in some for reasons of security. The presentation 

 on this basis has fortunately not been unduly restricted by the require- 

 ments of military security, although such requirements have in some 

 cases prevented inclusion of otherwise interesting information. The 

 writer is indebted to T. L. Brownyard of the Bureau of Ordnance, U. S. 

 Navy, for his assistance and advice on clearance, and to Stephen 

 Brunauer for his continued helpful interest in the work. 



The writer's experience in the field of underwater explosions is the 

 result of his association with the work of the Underwater Explosives 

 Research Laboratory, a wartime organization established under con- 

 tracts of the Woods Hole Oceanographic Institution with the Office of 

 Scientific Research and Development, and later with the Bureau of 

 Ordnance, U. S. Navy. Much of the illustrative material was draw^n 

 from the work of this laboratory, both because of this association and 

 because in some cases other equally pertinent data were for one reason 

 or another not available. The original impetus for the writing of this 

 book came from Paul C. Cross; the early planning of its scope and con- 

 tent benefited greatly from the advice and criticism of Dr. Cross and of 

 E. Bright Wilson, Jr. The actual writing of the book was begun at the 



