PHYSIOGRAPHIC PROBLEMS OF TODAY 549 



every branch of industry a critical knowledge of the physical condi- 

 tions, both favorable and adverse to the economic ends in vievv^, and 

 of the limitations of the daily, seasonal, and secular changes they 

 experience, is of primary commercial importance. Although the 

 money value of truth should be a secondary consideration to the truth- 

 seekers, a critical study of the influence of environment on industry 

 is as truly a matter of scientific research as any of the less complex 

 and less directly utilitarian branches of physiography. 



The reaction of human activities on physiographic features pre- 

 sents two great groups of problems. These embrace, on the one 

 hand, the far-reaching and frequently cumulative effects of man's 

 interference with the delicate adjustment reached in natural condi- 

 tions before his influence became manifest; and, on the other hand, 

 the effects of such changes on man's welfare. 



A change amounting to but little less than a revolution in the 

 long-established processes by which the features of the earth's sur- 

 face are modified and developed, accompanied the advancement of 

 man from a state of barbarism to one of civilization, and is most 

 strikingly illustrated when men skilled in the arts migrate to a pre- 

 viously unoccupied region. This new factor in the earth's history 

 demands conspicuous changes in the methods of study usually employed 

 by physiographers, and makes prominent a series of investigations 

 the full significance of which is as yet obscure. The wholesale 

 destruction of forests, drainage of marshes, diversion of streams, 

 building of restraining levees along river banks, tillage of land, 

 abandonment of regions once under cultivation, the introduction of 

 domestic animals in large numbers into arid regions and the conse- 

 quent modification, and frequently the destruction, of the natural 

 vegetal covering of the soil, and many other sweeping changes incident 

 to man's industrial development, are fraught with consequences 

 most significant to the student of nature, and of profound import to 

 the future of the human race. From the point of view of the physiog- 

 rapher, the ultimate result of these great changes in the surface con- 

 ditions of the earth can to a great extent be expressed in one word, 

 and that word is desolation. In view of the suicidal lack of fore- 

 thought manifest in the activities of peoples and, as experience shows, 

 increasing in many directions in destructiveness with industrial prog- 



