Inside front cover Copyright © by Abelard-Shuman, Ltd., New York. Reprinted by permission from _Inside the Atom_, Isaac Asimov, 1966. PHOTO CREDITS Cover The Metropolitan Museum of Art Page facing inside The “Horsehead” Nebula in Orion. Hale cover Observatories. Author’s Photo Jay K. Klein Contents page & Lick Observatory page 4 Page 7 New York Public Library 9 From _Discovery of the Elements_, Mary E. Weeks, Chemical Education Publishing Company, 1968. 12 Library of Congress 15 Sir George Thomson 18 Burndy Library 19 New York Public Library 21 Copyright © 1965 by Barbara Lovett Cline, reprinted from her volume _The Questioners: Physicists and the Quantum Theory_ by permission of Thomas Y. Crowell Company, Inc., New York. 22 & 23 Curie Foundation, Institute of Radium 26 Academic Press, Inc. 29 Van Nostrand Reinhold Company 31 Top, Nobel Institute; bottom, from _Discovery of the Elements_, Mary E. Weeks, Chemical Education Publishing Company, 1968. 32 From _Discovery of the Elements_, Mary E. Weeks, Chemical Education Publishing Company, 1968. 34 Top, Nobel Institute; bottom, Niels Bohr Institute. 36, 42, 44, & 45 Nobel Institute 48 Academic Press, Inc. 49 From _Discovery of the Elements_, Mary E. Weeks, Chemical Education Publishing Company, 1968. 60 Curie Foundation, Institute of Radium ★ U.S. GOVERNMENT PRINTING OFFICE: 1975—640—285/13 A word about ERDA.... The mission of the U. S. Energy Research & Development Administration (ERDA) is to develop all energy sources, to make the Nation basically self-sufficient in energy, and to protect public health and welfare and the environment. ERDA programs are divided into six major categories: · CONSERVATION OF ENERGY—More efficient use of existing energy sources, development of alternate fuels and engines for automobiles to reduce dependence on petroleum, and elimination of wasteful habits of energy consumption. · FOSSIL ENERGY—Expansion of coal production and the development of technologies for converting coal to synthetic gas and liquid fuels, improvement of oil drilling methods and of techniques for converting shale deposits to usable oil.