Boursy, John Giesen, and Edward Miloslavich, for assistance and criti- 

 cism rendered in discussing innumerable points at their meetings. 



And lastly, the author would be remiss in his duty did he not ex- 

 press his special thanks and appreciation to his co-worker of many years, 

 Professor John Giesen, whose loyalty and willingness to assist in every 

 way have made many additional hours of work possible on this book. 



EDWARD J. MENGE. 



Marquette University, 



Milwaukee, Wisconsin, 



June 25, 1922. 



