L. Phelps and Prof. Henry A. Beers; this edition was undertaken at the suggestion of the first and it was aided at every point by the profound and sub tle scholarship of the second. I also must state em phatically my obligation to Mr. Marshall C. Lef ferts; when he gave me access to his fine private col lections in this period, he rendered this work of mine possible. It remains in conclusion to gratefully ac knowledge the efforts of my wife and my sister in having read the proofs. J. M. B.