The Prevalence of Land Sculpture. 157 



factors. There is furthermore, a natural order of succession that 

 cannot wisely be ignored. That should be selected which comes 

 first to hand in natural order and is least dependent on other 

 factors. 



It is obvious that the study of the internal forces presents the 

 most obscure and difficult of the three fields. These forces were 

 very influential in determining the grosser outlines of the earth's 

 physiognomy, but they were onl}^ indirectly involved in de- 

 veloping the finer tracings of the earth's features, the lineaments 

 of which furnish the best subjects of detailed study in the earlier 

 courses. 



When the selection is limited to a choice between the sculp- 

 turing of the land and the deposition of the seas, the application 

 of the criteria above indicated seems at once decisive. We may 

 be said to be everywhere in contact with the land and in the 

 presence of land-sculpturing. We are only here and there in 

 contact with the seas or other depositional basins, and the pro- 

 cesses of strata-building and land-growth are not everywhere sub- 

 servient to direct study. We may be said to be constantly deal- 

 ing with the results of the disintegration, wear and wastage of 

 the land. We are only here and there immediately concerned 

 in the depositions of the seas or of like agencies. 



The natural sequence of processes brings the land action first 

 to our study. The material must be loosened and borne down 

 to the basins before it can be deposited. Derivation goes before 

 deposition. 



•The surface-shaping processes are simple in part and complex 

 in part. They present a gradation from simplicity to complexity, 

 and from ease to difficulty, that makes them happily subservient 

 to the skillful teacher in leading scholars on step by step from 

 the mastery of one point to another as their capacities develop 

 and their previous successes warrant. The processes of deposi- 

 tion and of land growth are simpler and have narrower limita- 

 tions and hence aff"orcl a less rich and pliable field for disciplinary 

 endeavors. 



The surface-shaping agencies are more intlmatel}^ associated 

 with human affairs and more determinative of human interests 

 than are the depositional processes. From many points of view, 

 therefore, if not from all, the sculpturing of the land constitutes 

 a more rich, pliable, and inviting field for the earlier educational 

 processes than the depositional work of the basins or the crust- 

 disturbing activities of the more obscure forces within the earth. 



