Image from the book “Analyzing Character” published by Katherine M.H. Blackford, MD, and Arthur Newcomb, 1916/1922
Accessed via Wikimedia Commons, 6/25/11
http://commons.wikimedia.org/wiki/File:William_Sydney_Porter.jpg
Used under the following terms of use:
http://creativecommons.org/licenses/by-sa/3.0/
For more information see the original Gutenberg source referenced by WikiMedia:
http://www.gutenberg.org/files/12649/12649-h/12649-h.htm#fig31