How to tell if you have the first or second printing of

EXPLANATORY SUPPLEMENT TO THE ASTRONOMICAL ALMANAC

You have the FIRST printing if

• the last digit that appears on the bottom of the copyright page, below the words "Printed in the United States of America," is  1

You have the SECOND printing if

• the last digit that appears on the bottom of the copyright page, below the words "Printed in the United States of America," is  2