reprinted by arrangement with 

 The Cranbrook Institute of Science 



Printed and Published by 



Hafner Publishing Company 



31 East 10th Street 



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Library of Congress Catalog Card Number 63-17545 



(§) copyright 1942 



The Cranbrook Institute of Science 



Bloomfield Hills, Michigan 



All rights reserved. This book, or parts thereof, may 

 not be published in any form without the written 

 permission of the publishers. 



