New York: Bell Telephone Laboratories 1930. 10 pages. Original blue printed paper wrappers with a touch of fading at the extremities. 6 x 9 inches, stapled, 3-hole punched as issued. Monograph B-502, July 1930, of the Bell Telephone System Technical Publications. Near Fine. Wraps. 
Clinton Joseph Davisson shared the Nobel Prize in Physics in 1937 with George Paget Thomson "for their experimental discovery of the diffraction of electrons by crystals." The article offered here was presented before The American Philosophical Society in Philadelphia, PA on April 12, 1930, was published in the Proceedings of the American Philosophical Society Vol LXIX, No 4, pp. 247-256, and here in July 1930. Bell Labs published the Monograph series which contained various articles felt to be interesting enough to warrant additional distribution. Many were first published in other journals but by Bell System employees, and are sometimes treated as "first separate editions" in cases where the other journals didn't issue offprints. They were primarily sold on a subscription basis to libraries and are thus scarce without library markings.