PREFACE V 



Professors A. S. Packard, J. H. Comstock, H. H. Wilder, J. I. 

 Hamaker, Frank Smith, H. B. Ward, E. L. Rice, H. L. Osborn, 

 H. L. Clark, C. W. Hargitt, and H. S. Jennings. Their criti- 

 cisms and suggestions have been most helpful and important, 

 and I wish to acknowledge a heavy obligation to each of them. 



H. S. PRATT. 

 HAVERFORD, PA., 

 October, 1901. 



