18 THE MAMMOTH CAVE. 



In preparing this history of the Mammoth 

 Cave, we make as much use as possible of the 

 materials just mentioned, collating their agree- 

 ments and disagreements with our own obser- 

 vations. We are chiefly indebted, however, to 

 the valuable Manual of Professor Wright for all 

 measurements and material facts, such as can 

 be acquired only by a protracted series of obser- 

 vations ; and we trust that this general an- 

 nouncement of the authorities that we draw 

 upon will serve us in many instances instead of 

 quotation-marks. 



