‎"SOMMERFELD, A. - THE BOHR-SOMMERFELD MODEL OF THE ATOM.‎
‎Zur Quantentheorie der Spektrallinien. I-III. (I. Theorie der Balmerschen Serie. II. Die Feinstruktur der Wasserstoff- und der wasserstoffähnlichen Linien. III. Theorie der Röntgenspektren.‎

‎Leipzig, Johann Ambrosius Barth, 1916. Contemp. hcloth. Gilt lettering to spine. VIII,888 a. 4 plates. (entire volume offered). Sommerfelds paper: pp. 1-94 a. pp. 125-167. A stamp on verso of titlepage. Clean and fine.‎

Reference : 45027

‎First appearance of Sommerfeld's elaborated version of the fine structure of the hydrogen atom, in which he was the first to show, that relativity theory gives a quantitative account of the fine structure, and thus creating a general theory of spectral lines based on the quantum concepts.""Sommerfeld's two papers...and a more elaborate version (the paper offered)...surely deserves a lenghty chapter in the history of the old quantum theory...""Pais, Bohr p. 186 ff).""This extraordinary extension, enrichment, and precision of Bohr’s theory by Sommerfed contributed decisively to its rapid and widespread acceptance. Only five years after Bohr’s first publication Sommerfeld, recognizing that the mathematical development of this quantum-theoretical atomic model had reached a conclusion of sorts, undertook a comprehensive exposition of the field. HisAtombau and Spektallinien, of which the first edition appeared late in 1919, immediately became the bible of atomic physics and its successive editions, appearing almost annually in the early 1920’s, chronicled the progress of this field up to the eve of the introduction of quantum mechanics.""(DSB). - Parkinson ""Breakthroughs"", 1916 P.The volume contains other notable papers by Paul S. Epstein ""Zur Quantentheorie"", Stark, P. Ehrenfest ""Adiabatische Invarianten und Quantentheorie"" and A. Einstein ""Über Friedrich Kottlers Abhandlung ""Über Einsteins Áquivalenzhypothese und die Gravitation"" pp. 639-642.‎