VOLUME I ONLY of two. RARE English translation of the fifth edition of Arnold Sommerfeld`s "Atomic structure and spectral lines", which appeared in two volumes, the first volume comprising the older quantum theory, while the second volume was supposed to be the elaboration and completion of the supplementary volume, which originally appeared under the title "Wave Mechanics". 220x150mm. XI+675 pages. Dark yellow cloth Hardcover. Cover scratched and stained. Cover corners and edges peeling. Spine detached (but present). Spine hinges tattered. Previous owner`s name written in pencil on front inner cover (Prof. Nissan Zeldes). Binding loose and visible on inner cover and between pages VI-1 and 67-671. Pages VII-XI detached from binding. Some pages upper corner slightly bumped/wrinkled. Pencil notes/underlining on few pages. Pages slightly yellowing. [SUMMARY]: This extremely rare English edition of Professor Sommefeld`s classic work is in good reading condition.