liberal citation of sources and the selected lists of supplementary reading should prove of considerable value.
In preparing this volume for press, I have received help from several quarters. For rendering more accurate my descriptions of educational administration in Europe (Chapter IX) and of the modern scientific movement (Chapter X), I am greatly indebted to Professor F. E. Farrington of Columbia University and to Professor G. R. Twiss of the Ohio State University respectively. I owe a more extensive debt to Professor J. H. Coursault of the University of Missouri, Professor A. J. Jones of the University of Maine, and Professor W. H. Kilpatrick of Columbia University, who have read through practically my entire manuscript, and suggested a wide variety of changes. Likewise my wife, Helen Wadsworth Graves, has been ever at hand to advise and assist me.
PHILADELPHIA,
November, 1913.