First published in the Dutch language 1948 

 First English edition 1954 



Published in Great Britain by Perganion Press Ltd. 

 Maxwell House, Marylebone Road, London N. W. I. 



Published in U.S.A. by the Me Graw-Hill Book Co.. Inc.. 

 330 West 42nd Street. New Yor/? 36, N.Y. 



Printed in the Netherlands by J. Noorduijn en Zoon N.V. 



