PUBLISHERS’ NOTE 
The consolidation of the three volumes of the Summary Technical Report 
of the Committee on Propagation of the National Defense Research Com- 
mittee was undertaken because the limited edition of the Report published 
by the Summary Reports Group of the Columbia University Division of War 
Research and distributed by the War and Navy Departments restricted the 
availability of this material after declassification. The manuscript and 
illustrations for the three volumes were prepared for publication by the 
Summary Reports Group of the Columbia Division of War Research. 
This volume contains all the scientific information and report of exper- 
iments contained in the three separate volumes and omits only that part 
relating to the administrative activities of the Committee, its origin and 
organization, with a description of the needs of the armed forces which called 
it into being. 
THE PUBLISHERS 
December 1948 
