Advances in Geogeaphic Knowledge 143 



woodlands despoiled into sterile wastes; 

 fields have been ill- wrought into barren- 

 ness and then turned out to wash into 

 neighboring waterways, thereb}^ ruin- 

 ing both hill and dale ; mines and quar- 

 ries have been so unwisely worked as to 

 check other industries for decades and 

 entail public losses far exceeding per- 

 sonal gains. In legion ways the adjust- 

 ment of American settlers to new en- 

 vironments has been destructive, yet no 

 new contacts have been more disastrous 

 than those between the pioneers from 

 humid fatherlands and the finely -bal- 

 anced vital solidarities of arid regions ; 

 and of all the examples of destructive 

 contact between pioneers and precursors 

 none are more impressive than those 

 so clearly attested by the Old Yuma 

 Trail. 



Happily, the dark lines of the picture 

 carry a brighter complement : Science — 

 and American progress is but science 

 practically applied — advances through 

 experiences, both of success and failure; 

 no success could be more instructive 

 than the failure attested bj^ the aban- 



donment of the country along the his- 

 toric route; and this failure at once 

 attests the folly of disregarding natural 

 conditions when settlement is pushed 

 into unfamiliar regions, and indicates 

 the wisdom of weighing natural condi- 

 tions as means of nature- conquest. The 

 natural potentialitj' of the country trav- 

 ersed by the old trail is proved by the 

 condition of the neighboring plains on 

 the southern side of the Sonoran bound- 

 ar}^ which have never been overstocked — 

 plains still mantled with herbage and 

 grazed b}^ herds of deer as in pre-Colum- 

 bian times ; and the slow resetting of 

 shrubbery along the old wa)' gives defi- 

 nite promise of restoration to the early 

 state, while the moderate fruitfulness of 

 the Sonoran plains points a way in which 

 the growing resources may be utilized 

 by patient adjustment of industries to 

 natural conditions. 



So the wisdom, if not the imperative 

 necessit}', of adjusting means to condi- 

 tions in the reclamation of arid lands is 

 the leadling lesson of the Old Yuma 

 Trail. 



ADVANCES IN GEOGRAPHIC KNOWLEDGE 

 DURING THE NINETEENTH CENTURY* 



By Brig. -Gen. A. W. Greely, Chief Signal Officer, 



U. S. Army 



IN these days geographic exploration 

 means not merely the topographic 

 distribution of mountain or river, 

 of lake or plain, but also the determina- 

 tion, in a cursory manner at least, of 

 existent vegetable and animal life, of 

 climatic conditions, and especially of the 

 ethnology of inhabited areas. 



* Revised and republished by conrtes}- of 

 the publishers of the New York Tribune. 



In forecasting the evolution of any 

 aspect of the twentieth century the 

 soundest base must be the advances of 

 the nineteenth centur}^ along like lines 

 of research. Judged by this standard, 

 the present century will perfect the aspi- 

 rations of the explorer of the last century 

 to make known the entire surface of the 

 earth. Few appreciate the enormous ad- 

 vances in geographic knowledge dur- 



