A WORD TO THE 

 READER 



THERE are two classes of mind, 

 which, when earnestly employed, 

 are rarely combined in the same 

 person; the investigator and the re- 

 corder,, and when so combined, time 

 becomes the one element lacking. The 

 investigator and the experimenter who 

 is seeking practical results which shall 

 be of lasting benefit to the race, cannot 

 keep verbose records. He must be on 

 the alert in seeking the shortest and 

 best methods which shall lead to the 

 results sought. 



These eight volumes are not a com- 

 pilation from the works or words of 

 others, but a description of some of the 



17 



