National Geographic : 1899 Nov
THE RATIONAL ELEMENT IN GEOGRAPHY his elementary study and advance toward much broader corre lations by which the forms of large areas are brought into har monions association. Systematic geography will thus come to serve the same important object as systematic zoology or botany; it will provide convenient means of assembling a great body of facts in what is believed to be their natural relations, and it will devise an accurate terminology by which rational and effective description can be given to a vast variety of land forms through their likeness to or difference from many standard types. In my own experience, the dominating principle of systematic geography is that of the geographical cycle, of which some ac count has been given on an early page of this Magazine (vol. i, 1889, p. 20), and in various later articles, and of which a fuller statement appears in the current number of the (London) Geo graphicalJournal. With increasing experience in its application, the'more comprehensive, powerful, and practically useful has the principle of the cycle become. It is now an indispensable guide in observation as well as description, because it leads off a whole procession of facts, marshalling them in good order. From its earliest and most general application to consequent streams, it is now extended to streams of many kinds, systemat ically acting on one another in the rearrangement of their drain age areas during their progressive adjustment to the structures on which they work. The cycle accommodates itself easily to the peculiar conditions of arid or frigid climates, and to the spe cial conditions of the seashore. It stimulates the recognition of real homologies: the rudimentary conception of land drainage as limited to streams of water has thus been expanded so as to include all lines of down-hill movement, whether of water or waste ; and the generalized river is thus seen to cover all the sur face of its basin. A graded condition or " profile of equilibrium " is first attained by the trunk river on areas of weak rocks and last attained by the creeping waste near the divides on areas of resistant rocks, and the geological theory of evolutionary uni formitarianism receives new support from the correspondence between the generalizations thus reached and the facts of nature. However theoretical all this may seem to be, I do not believe there is any more practical means of land-form study than is found in the application of the principles here referred to. I earnestly urge teachers of whatever grade to make themselves acquainted with the geographical cycle, and to introduce its ele ments appropriately in their teaching.