VI PREFACE. 



I take tliis opportunity to thank Professor Doctor H. 

 Moller for his great kiudness. 



I am also under obligations to Messrs. Parey, Cox and 

 Lupton, for granting me the use of various cuts, some of 

 which have been remodeled to more clearly illustrate points 

 of interest. 



In conclusion, I wish to express thanks to my publisher, 

 William R. Jenkins, for the liberal assistance rendered 

 me in every respect. 



W. E. A. WYMAN. 



Clemson College, S. C= 



