scattered manifoldness of scientific endeavor with which the twentieth century has opened. [Illustration: _Simon Newcomb, Ph.D., LL.D._ Dr. Newcomb, the famous Astronomer, is conceded to be the Dean of American scientists. His eminent services to the Government of the United States, and his recognized position in foreign and domestic scientific circles, made him peculiarly fitted to deliver the introductory address, and to officiate as President of an International Congress of the leading scientists of the world. He has been the recipient of honorary degrees from six American and ten European Universities, and he is a member of almost every important Academy of Science in Europe and America. He is an officer of the Legion of Honour, and is the only native American besides Benjamin Franklin who has been elected an Associate of the Institute de France. From 1861 to 1897 he was Professor of Mathematics in the United States Navy. He also lectured on Mathematics and Astronomy at Johns Hopkins, and is now a Professor Emeritus in the Faculty of Arts of that university. Dr. Newcomb is the author of numerous works on Astronomy and other scientific subjects.] PROCEEDINGS OF THE CONGRESS INTRODUCTORY ADDRESS DELIVERED AT THE OPENING EXERCISES AT FESTIVAL HALL BY PROFESSOR SIMON NEWCOMB, PRESIDENT OF THE CONGRESS THE EVOLUTION OF THE SCIENTIFIC INVESTIGATOR As we look at the assemblage gathered in this hall, comprising so many names of widest renown in every branch of learning,--we might almost say in every field of human endeavor,--the first inquiry suggested must be after the object of our meeting. The answer is, that our purpose corresponds to the eminence of the assemblage. We aim at nothing less than a survey of the realm of knowledge, as comprehensive as is permitted by the limitations of time and space. The organizers of our Congress have honored me with the charge of presenting such preliminary view of its field as may make clear the spirit of our undertaking.