This is not the first time Houdini's palm appeared in newsprint. In 1900 a Kansas City paper reported that Houdini had his "hand examined" by a local palm-reader, Professor Paul Alexander Johnston, and ran the illustration below. This shows his left hand, so that gives us both of Houdini's palms to examine.
Does this mean Houdini believed in palmistry? Before we jump to that conclusion, let's hear from the man himself. The topic came up during Houdini's 1926 testimony before Congress, and here's what he had to say:
Mr. McLeod: Is it a fact that palmistry is a science?Mr. Houdini: No; it is not.Mr. McLeod: What do you call it?Mr. Houdini: It is a fraud. How can you tell anything the lines of the hand? You can tell whether a man is a bricklayer or a bank clerk.Mr. McLeod: And that is as far as you can go?Mr. Houdini: That is a far as anybody can go unless they deduce from reading you.
Sounds like he's using his cross of keen observation.
Images: Newspapers.com and 'Houdini His Legend and His Magic' by Doug Henning.

