The method of anthropo-geography is essentially analytical, and therefore finds little use for general orometric statements, which may be valuable to the science of geo-morphology with its radically different standpoint.  For instance, geo-morphology may calculate from all the dips and gaps in the crest of a mountain range the average height of its passes, Anthropo-geography, on the other hand, distinguishes between the various passes according as they open lines of greater or less resistance to the historical movement across the mountain barriers.  It finds that one deep breach in the mountain wall, like the Mohawk Depression[1027] and Cumberland Gap in the Appalachian system,[1028] Truckee Pass in the Sierra Nevada[1029] and the Brenner in the Alps,[1030] has more far-reaching and persistent historical consequences than a dozen high-laid passes that only notch the crest.  Pack-trail, road and railroad seek the former, avoid the latter; one draws from a wide radius, while the other serves a restricted local need.  Therefore anthropo-geography, instead of clumping the passes, sorts them out, and notes different relations in each.

[Sidenote:  Distribution of reliefs.]

In continents and countries the anthropo-geographer looks to see not what reliefs are present, but how they are distributed; whether highlands and lowlands appear in unbroken masses as in Asia, or alternate in close succession as in western Europe; whether the transition from one to the other is abrupt as in western South America, or gradual as in the United States.  A simple and massive land structure lends the same trait of the simple and massive to every kind of historical movement, because it collects the people into large groups and starts them moving in broad streams, as it were.  This fact explains the historical preponderance of lowland peoples and especially of steppe nomads over the small, scattered groups inhabiting isolated mountain valleys.  The island of Great Britain illustrates the same principle on a small scale in the turbid, dismembered history of independent Scotland, with its Highlanders and Lowlanders, its tribes and clans separated by mountains, gorges, straits, and fiords,[1031] in contrast to the smoother, unified course of history in the more uniform England.  Carl Ritter compares the dull uniformity of historical development and relief in Africa with the variegated assemblage of highlands and lowlands, nations and peoples, primitive societies and civilized states in the more stimulating environment of Asia.[1032]

[Sidenote:  Homologous relief and homologous histories.]