Notes: First Printing, June, 1969 without a number line is on the copyright page. The cover notes this edition as Comprehensively revised and up-to-the-minute, and there are multiple copyright dates from 1944 to 1968. The 1968 Viking edition was the first to appear with this title. The cover picture may be a painting but no credit is given, if it is a grainy photo then it has to be from NASA. There are 32 pages of photographs bound in between pages 352/353. The Foreword and the TOC have Roman numerated pages [v-xviii] but the pagination is continuous from those to the text which starts on page 19