This is the reprint of a well-known and valuable work that has been out of print and widely sought for a number of years. A volume in the series Source Books in the History of the Sciences, it consists of selections from the writings of the great physicists from the sixteenth through the nineteenth century—such figures as Galileo and Newton, Franklin and Faraday, Rowland, Hertz, and the Curies—making available to the student in English translation their most important contributions, described in their own words, together with biographical and explanatory notes by the editor.