vi PREFACE 
physics Research Division in this undertaking. The Division’s library was kindly made available for use in the 
editorial work and the friendly counsel and suggestions of Division personnel have been most helpful. Sincere ap- 
preciation is due to Professor Hans Neuberger for carefully checking and editing the papers translated from the 
German. Miss Eleanor Richmond and Mr. W. Lawrence Gates have labored long and faithfully in systematizing 
and checking the lists of references and in assisting with the editing and proofreading. The assistance of Mr. Jean 
Le Corbeiller in the editorial work and proofreading is also gratefully acknowledged, as is the careful proofreading 
by Mrs. William Greene and Mrs. Israel Kopp. Mr. Kenneth C. Spengler, executive secretary of the American Mete- 
orological Society, his assistant, Mrs. Holt Ashley, and their staff have capably handled all of the administrative 
matters connected with this work. Preparation of the illustrations for publication has been efficiently accomplished 
by Mr. Chester Jancewicz. 
BOSTON, MASSACHUSETTS . T.F.M. 
August 1951 
