EMORY R. JOHNSON, A. M., _Assistant Professor of Transportation and Commerce, University of Pennsylvania_. THE CENTURY’S COMMERCIAL PROGRESS. FRANKLIN S. EDMONDS, A. M., _Assistant Professor of Political Science, Central High School, Philadelphia_. THE CENTURY’S ADVANCES IN EDUCATION. THOMAS J. LINDSEY, _Editorial Staff Philadelphia “Evening Bulletin.”_ “THE ART PRESERVATIVE.” GEORGE A. PACKARD, _Metallurgist and Mining Engineer_. PROGRESS IN MINES AND MINING. JOHN V. SEARS, _Art Critic Philadelphia “Evening Telegraph.”_ ART PROGRESS OF THE CENTURY. J. MADISON TAYLOR, M. D., AND JOHN H. GIBBON, M. D., _Surgeons Out-Patients Departments of Pennsylvania and Children’s Hospitals_. THE CENTURY’S ADVANCE IN SURGERY. FRANK C. HAMMOND, M. D., _Instructor in Gynæcology, Jefferson Medical College_. PROGRESS OF MEDICINE. E. E. RUSSELL TRATMAN, C. E., _Assistant Editor of “Engineering News,” Chicago, Ill._ EVOLUTION OF THE RAILROAD. LUTHER E. HEWITT, L. B., _Librarian of Philadelphia Law Association_. ADVANCE IN LAW AND JUSTICE. MICHAEL J. BROWN, _Secretary of Building Association League of Pennsylvania_. PROGRESS OF BUILDING AND LOAN ASSOCIATIONS. REV. A. LEFFINGWELL, _Rector Trinity Church, Toledo, O._ EPOCH MAKERS OF THE CENTURY. ANALYSIS OF CONTENTS WONDERS OF ELECTRICITY