NDRC FOREWORD 



As EVEXTS of the years preceding 1940 revealed 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. Eecommendations 

 which they made to the White House were given care- 

 ful and sympathetic attention, and as a result the 

 National Defense Eesearch Committee [NDKC] was 

 formed by Executive Order of the President in the 

 summer of 19-10. The members of NDEC, appointed 

 by the President, were instructed to suj^plement the 

 work of the Army and the Na^'y in the development 

 of the instrumentalities of war. A year later, upon the 

 establishment of the Office of Scientific Eesearch and 

 Development [OSED], NDEC became one of its units. 



The Summary Technical Eeport of NDEC is a 

 conscientious effort on the part of NDEC to summa- 

 rize and evaluate its work and to present it in a useful 

 and permanent form. It comprises some seventy vol- 

 umes broken into groups corresponding to the NDEC 

 Divisions, Panels, and Committees. 



The Summary Technical Eeport 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 undertaken. Some volumes may 

 be "state of the art" treatises covering subjects to 

 which various research groups have eontribiited in- 

 formation. Others may contain descriptions of devices 

 develof)ed in the laboratories. A master index of all 

 these divisional, panel, and committee reports which 

 together constitute the Summary Technical Eeport 

 of NDEC is contained in a separate volume, which 

 also includes the index of a microfilm record of per- 

 tinent technical laboratory reports and reference 

 material. 



Some of the NDEC-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 sam- 

 pling inspection by the Applied Mathematics Panel. 

 Since the material treated in them is not duplicated 



in the Summary Technical Eeport of NDEC, the 

 monographs are an important part of the story of 

 these aspects of NDEC research. 



In contrast to the information on radar, which is 

 of widespread interest and mucli 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 Eeport, which runs to over twenty volumes. 

 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 Eeport of NDEC: 

 account must be taken of the monographs and avail- 

 able reports publislied elsewhere. 



Though the Committee on Propagation had a com- 

 paratively short existence, being organized rather late 

 in the war program, its accomplishments were defi- 

 nitely effective. That so many individuals and organ- 

 izations worked together so harmoniously and con- 

 tributed so willingly to the Committee's efforts is a 

 tribute to the leadership of the Chairman, Charles E. 

 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 members 

 of the Committee and its contractors, but also to the 

 many other individuals who gave so generously of 

 their time and efliort. This group included a number 

 of our Canadian and British allies. In addition to tlie 

 assistance given the war effort, a considerable contrib- 

 ution has been made to the knowledge of short-wave 

 transmission and especially to the interrelation of this 

 phenomenon with meteorological conditions. Such in- 

 formation will be most valuable in weather forecasting 

 and in furthering the usefulness of the whole radio 

 field. 



Vannevae Bush, Director 



Office of Scientific Research and Development 



J. B. CoNANT, Chairman 

 National Defense Research Committee 



