First published, October 1955
Second Impression November 1955
Third Impression January 1957
Fourth Impression May 1958
Fifth Impression 1959
Sixth Impression 1960
Seventh Impression 1961
Eighth Impression 1961
Ninth Impression 1962
Tenth Impression 1963

This book is copyright under the Berne Convention. Apart from any fair dealing for the purposes of private study, research, criticism or review, as permitted under the Copyright Act 1956, no portion may be reproduced by any process without written permission. Enquiry should be made to the publisher.

Printed in Great Britain
in 11 on 12 point Imprint type
by Jarrold & Sons Ltd,
Norwich