PHYSICAL GEOGRAPHY IN THE UNIVERSITY. 9 1 



anced relations of carrying power and load involved in the 

 explanation of the growth of delta may not be perceived unless 

 it is carefully discussed in making out the scheme of river devel- 

 opment. There can be no thoroughness of work where obser- 

 vation and explanation are slurred over or confused. After 

 observation and description are well advanced, explanatory terms 

 may be introduced ; it then being seen that such terms imply a 

 pairing off of observed facts with the appropriate members of 

 the deductive scheme. This mental process must become per- 

 fectly conscious ; its several steps must be recognized in their 

 proper relations. No strong grasp of the subject can be gained 

 until the student sees clearly where every part of the work stands 

 in relation to the whole. 



Topographical maps published by the U. S. governmental bureaus. — 

 It is difficult to secure a full series of facts for laboratory study. 

 My plan at present is to select maps from our own surveys and 

 from the surveys of foreign countries, with little regard to local- 

 ity, but with much regard to geographical features. The charts 

 of our coast survey offer admirable illustrations of litoral forms. 

 For example, the sand-bar cusps of Capes Hatteras, Fear, and 

 Lookout, and their off-shore shoals, all formed between back-set 

 eddy currents, rotating betwixt the Gulf stream and coast ; or the 

 blunted Canaveral cusp on the Florida coast, and its southward 

 migration from a former position ; or the fjords and islands of 

 Maine ; the sounds of North Carolina ; the delta of the Missis- 

 sippi, a geographical gem.^ The maps of the Mississippi River 

 Commission offer remarkable illustrations of the behavior of a 

 large river on its alluvial plain. Its meanders, its cut-offs, and 

 its ox-bow lakes are shown to perfection. The eight-sheet map 

 of the alluvial basin of the Mississippi, prepared by this commis- 

 sion, can be had for a merely nominal charge ; it exhibits the 

 lower part of the great river in an admirable manner. It tells 

 the curious story of streams that descend from the eastern bluffs, 



' It is not generally enough known that the illustrated catalogue of the Coast Sur- 

 vey Charts may be had free of charge on application by responsible persons to the 

 Superintendent of the Survey in Washington. 



