The Theory of Spectra and Atomic Constitution: Three Essays, by Niels 47464 [Full title: The Theory of Spectra and Atomic Constitution: Three Essays] [Full author's name: Niels Bohr] [Author: Niels Bohr] [Link: https://www.gutenberg.org/4/7/4/6/47464] [File: 47464-h.htm] Thanks to Andrew D. Hwang. HTML version by Laura Natal. (This ebook was produced using scanned images and OCR text generously provided by the Brandeis University Library through the Internet Archive.) This is an update to the original 47464. It adds an HTML version (with svg illustrations) to the existing Tex version. Regards, Al