The Official Handbook for Boys, 2nd edition (1914-1927; 2.6 million copies printed). Author credit: BSA Editorial Board & various experts. Cover illustration: J. C. Leyendecker.
J. C. Leyendecker's cover illustration for the second edition of the Handbook (1914-1927), originally used as a Saturday Evening Post cover, contains errors. The boy is using Morse Code flags to send semaphore signals. Leyendecker's illustration was corrected in 1921 (after 14 printings) when the flags were changed from Morse (nested squares) to semaphore flags (single squares split diagonally into two triangles).