of acknowledging my indebtedness to the ingenuity and intelligence displayed by them in the discovery of certain illustrative documents. I have been constantly aided in the work of selection, translation, and editing by Dr. Helen Gertrude Preston of the Girls' High School of Philadelphia. Professor James Harvey Robinson, the editor of the series of which this volume is a part, through our long labors together over manuscript and proof, has often contributed the last and best word of suggestion, advice, or decision.
EDWARD P. CHEYNEY
UNIVERSITY OF PENNSYLVANIA