GEOLOGY AS AN ECONOMIC 

 SCIENCE 



By HERBERT H. THOMAS, Sc.D. 

 Secretary of the Geological Society of London. 



Geological science is the necessary outcome of 

 the relations between Man as a reasoning being and 

 the inanimate Earth on which he lives, and as such 

 has gradually evolved from the dark ages of un- 

 tutored observation and superstitious beliefs. There 

 existed a Geology, and there were geologists such 

 as Lehmann, Guettard and Werner, previous to the 

 nineteenth century, but the true science had its 

 birth a little more than a hundred years ago, as 

 soon as it was recognised that the strata forming 

 the Earth's crust were not thrown together in a 

 fortuitous manner, but were superposed the one 

 upon the other in a definite and invariable sequence. 

 The work of William Smith in Britain, and of 

 Cuvier, Brongniart and Lamarck in France, demon- 

 strated, even to the most sceptical, that the various 

 strata exposed at the surface could be traced, by 

 means of definite characters that they possessed and 



