PREFACE. xiii 



are practically applied in subsequent chapters. Lastly, as 

 a statement is usually more likely to be credited if it be 

 supported by the authority of great or ancient names, 

 I have in many instances preferred to insert the opinions 

 of others in confirmation of my conclusions rather than 

 state my own. 



My best thanks are due to the Eev. Sir Gr. W. Cox, 

 Bart., for examining the manuscript and correcting the 

 proof-sheets, and to Professor JEVONS, LLJX, F.E.S., for 

 correcting a portion of them. The corrections were 

 copied by my assistant, H. W. BROWN. 



