792 STUDIES FOR STUDENTS 



another, the worker giving to each what weight in his judg- 

 ment is best to secure a compromise for the result. They are 

 perhaps as good a set of rules as we can secure for the settle- 

 ment of matters regarding which the known facts are insufficient 

 to allow of a definitive conclusion. 



A map constructed upon observations and rules as above 

 outlined might be difficult to read, as the order of superposition 

 of the formations might not at once be clear. The formations 

 do not always appear upon the map in their direct order, being 

 sometimes inverted, and sometimes individual formations do not 

 lie next to their immediate neighbors above and below. The 

 map maker is expected to show how each formation has been 

 brought into its present positions and attitudes, to do which 

 fundamental assumptions of far-reaching importance are made 

 Theory is thereby brought in very large measure into the solu- 

 tion of the problem, it may be so as to take precedence over the 

 canons of doctrine which have been outlined above. These 

 basal assumptions and their effect upon the map will be con- 

 sidered in a second paper. 



William Herbert Hobbs. 



