JOHN SAMUEL ENYS, ESQ., 
FELLOW OF THE GEOLOGICAL SOCIETIES OF LONDON AND CORNWALL ; 
VICE-PRESIDENT OF THE ROYAL POLYTECHNIC SOCIETY OF CORNWALL ; ASSOCIATE OF THE 
INSTITUTION OF CIVIL ENGINEERS, 
&c., &c., &c. 
OF ENYS, CORNWALL, 
THIS WORK IS DEDICATED BY 
HIS FRIEND, 
THE AUTHOR.