X ACKNOWLEDGMENTS 



Any attempt of the author to acknowledge obUgations would be incomplete, 

 indeed, without mention of the extreme readiness to serve and cooperate on 

 the part of Dr. James B. Lackey, then Science Editor of The Blakiston Co. 

 (presently Research Professor, School of Engineering, University of Florida), 

 and also to Irene Claire Moore, then Assistant Manuscript Editor (presently 

 Book Editor, United Lutheran Publication House, Philadelphia), and to W. T. 

 Shoener, Production Manager. 



The Author 

 Autumn 1952 

 Philadelphia, Pa. 



