London Underground ‘Diagram of Lines and Station index. Original 1958 map by H.C. “Harry” Beck, dated 1958 to bottom right of front cover (see scan in Product Gallery.) Shows H.C. Beck imprint at bottom left corner of diagram. Printed by Johnson Riddle & Co. Ltd, St. Mary Cray, Kent. Size approx. 9 x 6 inches. Excellent condition.