NDRC FOREWORD 



As EVENTS of the years preceding 1940 revealed 

 Xi. more and more clearly the seriousness of the 

 world situation, many scientists in this country 

 came to realize the need of organizing scientific 

 research for service in a national emergency. Recom- 

 mendations which they made to the White House 

 were given careful and sjmipathetic attention, and 

 as a result the National Defense Research Com- 

 mittee [NDRC] was formed by Executive Order 

 of the President in the summer of 1940. The members 

 of NDRC, appointed by the President, were in- 

 structed to supplement the work of the Army and 

 the Navj^ in the development of the instrumentalities 

 of war. A year later upon the establishment of the 

 Office of Scientific Research and Development 

 [OSRD], NDRC became one of its units. 



The Summarj^ Technical Report of NDRC is a 

 conscientious effort on the part of NDRC to sum- 

 marize and evaluate its work and to present it in a 

 useful and permanent form. It comprises some 

 seventy volumes broken into groups corresponding 

 to the NDRC Divisions, Panels, and Committees. 



The Summarj' Technical Report of each Division, 

 Panel, or Committee is an integral survey of the 

 work of that group. The first volume of each group's 

 report contains a summary of the report, stating 

 the problems presented and the philosophy of 

 attacking them, and summarizing the results of the 

 research, development, and training activities under- 

 taken. Some volumes may be "state of the art" 

 treatises covering subjects to which various research 

 groups have contributed information. Others may 

 contain descriptions of devices developed in the 

 laboratories. A master index of all these divisional, 

 panel, and committee reports which together con- 

 stitute the Summary Technical Report of NDRC is 

 contained in a separate volume, which also includes 

 the index of a microfilm record of pertinent technical 

 laboratory reports and reference material. 



Some of the NDRC-sponsored researches which 

 had been declassified by the end of 1945 were of 

 sufficient popular interest that it was found desirable 

 to report them in the form of monographs, such as 

 the series on radar by Division 14 and the monograph 

 on sampling inspection by the Applied Mathematics 



Panel. Since the material treated in them is not 

 duplicated in the Summary Technical Report of 

 NDRC, the monographs are an important part of 

 the story of these aspects of NDRC research. 



In contrast to the information on radar, which is of 

 widespread interest and much of which is released 

 to the public, the research on subsurface warfare is 

 largely classified and is of general interest to a more 

 restricted group. As a consequence, the report of 

 Division 6 is found almost entirely in its Summary 

 Technical Report, which runs to over twenty vol- 

 umes. The extent of the work of a division cannot 

 therefore be judged solely by the number of volumes 

 devoted to it in the Summary Technical Report of 

 NDRC: account must be taken of the monographs 

 and available reports published elsewhere. 



Though the Committee on Propagation had a 

 comparatively short existence, being organized 

 rather late in the war program, its accomplishments 

 were definitely effective. That so many individuals 

 and organizations worked together so harmoniously 

 and contributed so willingly to the Committee's 

 efforts is a tribute to the leadership of the Chairman, 

 Charles R. Burrows. The latest information in this 

 field was gathered from the four corners of the earth, 

 organized, and dispatched to the points where it 

 would aid most in the prosecution of the war. 



Much credit must be given, not only to the mem- 

 bers of the Committee and its contractors, but also 

 to the mam' other individuals who gave so gener- 

 ously of their time and effort. This group included a 

 number of our Canadian and British allies. In addi- 

 tion to the assistance given the war effort, a consider- 

 able contribution has been made to the knowledge of 

 short-wave transmission and especially to the inter- 

 relation of this phenomenon with meteorological 

 conditions. Such information will be most valuable 

 in weather forecasting and in furthering the useful- 

 ness of the whole radio field. 



Vannevar Bush, Director 

 Office of Scientific Research and Development 



J. B. Conant, Chairman 



National Defense Reseaixh Committee 



