In a message dated 3/30/2008 6:19:38 P.M. Eastern Daylight Time, TAEdisonJR at aol.com writes: Edison wrote about this in his notes on July 3, 1878: "We find that the lattice girders some of which are weighted in middle acts as reeds and continue the vibration for a long time after the train has passed . . . We find that the diagonal cross rods vibrate strongly." ================ It is interesting to observe that Edison came to this recording business "backwards", i.e. he seems to have worked with the Phonautograph AFTER developing his own machine, whereas most people would look at the natural sequence as Scott first (recording), and then TAE (with reproduction). The Smithsonian's Phonautograph (still there) was supposedly purchased by them in 1866 from Rudolf Koenig for 500 francs. One wonders if Edison (visiting Wash DC) had ever remarked on that display prior to his invention of the phonograph. TAE seems to have come upon his own discovery 'ab initio,' from telephone diaphragms and telegraph repeaters, and not from Leon's machine... very ironic. Next, we will have Thomas Young's 'Vibrograph.' (1806). That may yield only the tones of a tuning fork. Allen _www.phonobooks.com_ (http://www.phonobooks.com) **************Create a Home Theater Like the Pros. Watch the video on AOL Home. (http://home.aol.com/diy/home-improvement-eric-stromer?video=15&ncid=aolhom00030000000001)