  In 1895 Hendrik Antoon Lorentz derived the Fresnel dragging coefficient in
his theory of immobile ether and electrons. This derivation did not explicitly
involve electromagnetic theory at all. According to the 1922 Kyoto lecture
notes, before 1905 Einstein tried to discuss Fizeau's experiment "as originally
discussed by Lorentz" (in 1895). At this time he was still under the impression
that the ordinary Newtonian law of addition of velocities was unproblematic. In
1907 Max Laue showed that the Fresnel dragging coefficient would follow from a
straightforward application of the relativistic addition theorem of velocities.
This derivation is mathematically equivalent to Lorentz's derivation of 1895.
From 1907 onwards Einstein adopted Laue's derivation. When Robert Shankland
asked Einstein how he had learned of the Michelson-Morley experiment, Einstein
told him that he had become aware of it through the writings of Lorentz, but
only after 1905 had it come to his attention. "Otherwise", he said, "I would
have mentioned it in my paper". He continued to say that the experimental
results which had influenced him most were stellar aberration and Fizeau's
water tube experiment. "They were enough". Indeed the famous Michelson-Morley
experiment is not mentioned in the 1905 relativity paper; but curiously
Einstein did not mention Fizeau's experimental result either, and this is
puzzling in light of the importance of the experiment in Einstein's pathway to
his theory. In this paper I try to discuss this question.
