In a message dated 4/10/2010 2:14:23 A.M. Eastern Daylight Time, [log in to unmask] writes: "That is why he (Edison) had such a huge library. I am sure he knew about Scott, and I suspect he knew about Cros. The evidence might still be in his library, not in his lab notes." -------------- Edison may well have known something about Scott (whose work was already in translation by 1863, Ganot), and maybe even Young (1807), but how could he know about Cros (whose La Semaine du Clerge first occurred on Oct 10th, 1877 and whose sealed packet was opened on Dec 3, 1877)? TAE's essential observation occurred on July 18th of that year. Allen