c. 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 

 VOLUME 140, NUMBER 3 



DOCTOR LANGLEY'S PARADOX: TWO 



LETTERS SUGGESTING THE 



DEVELOPMENT OF ROCKETS 



(With TaREt Plates) 



By 



RUSSELL J. PARKINSON 



Museum Aide, National Air Museum, Smithsonian Institution; and 

 Instructor of History, Duke University 



(Publication 4424) 



.Xi-^HSnAT" CITY OF WASHINGTON 



PUBLISHED BY THE SMITHSONIAN INSTITUTION 

 ^^ . AUGUST 31, 1960 



SEP 2 liJ 



