  This article discusses new material, published in Volume 12 of the Collected
Papers of Albert Einstein, that addresses Einstein's knowledge of the
Michelson-Morley experiment prior to 1905: in a lecture in Chicago in 1921,
Einstein referred to the experiment, mentioned when he came upon it, and hinted
at its influence. Arguments are presented to explain the contrast with
Einstein's later pronouncements on the role of the experiment.
