THE LEWIS BROOKS MUSEUM. 25 



The relations of Geology to Astronomy are closer than 

 they might, at first sight, be supposed to be. Our globe 

 must be studied, not only in its parts, but as a whole. As- 

 tronomy, in the modified nebular hypothesis of Laplace, 

 oners the most probable theory of the genesis of the earth 

 as a planet. She offers also plausible explanations of the 

 former changes of temperature on the surface of the earth, 

 those changes which gave rise to cold and warm periods. 



To Astronomy too we must look for the origin of the 

 meteoric stones, which perform the theoretically important 

 part of adding to the original amount of matter in the 

 earth. We must study also the Dynamics of nature in the 

 earth, as it lies before us,- in order to obtain light on past 

 events in its history. For this purpose the aid of Physical 

 Geography must be invoked. This science, as at present 

 limited, is an ill-defined branch of Natural Science. It 

 trenches upon the domain of Geology, Mineralogy, Zoology 

 and Botany. It has properly for its object the study of the 

 earth in its present condition, and should begin where Ge- 

 ology ends. 



Having pointed out some of the relations of the several 

 branches of Natural Science, we may now consider for a 

 while a few of the important and useful applications which 

 Geology allows. 



The first point which may engage our attention is the 

 great value of the study of Geology, in educating and ex- 

 panding the mind, and in supplying it with food for thought. 

 Dealing as it does, with nature immediately, and embracing 

 the entire range of her operations and products^ no study is 

 so well fitted to employ, educate and develop all the powers 

 of man. No study touches so many points in his mental and 

 physical nature. Geology develops and trains, in an emi- 

 nent degree, the powers of observation and discrimination. 



It demands originality in the observer. He is bound 

 by no fetters of authority, has to obey no rigid rules^ which 



