272 NINTH ANNUAL REPORT OF 



REMARKS CONTRIBUTING TO THE PHYSICAL GEOGRAPHY OF THE 

 NORTH AMERICAN CONTINENT. 



BY JULIUS FROEBEL. 



San Francisco, December 8, 1854. 



Since the annexation of California our geographical knowledge of thf 

 western half of our continent has made a progress the rate of which is 

 unsurpassed in the history of geography, and almost equals the fastnes- 

 of California life itself, by which it has been produced. In every 

 direction the great, wilderness of the western table-lands, and of the 

 continental slope along the Gila and Colorado, together with the ad- 

 joining portion of Sonora, is traversed by engineers, by cattle traders, 

 emigrants, prospecting miners, and bold adventurers, who all contribute 

 in daily augmenting our store of topographical details concerning these 

 vast regions. But while this store is accumulating, it cannot be ex- 

 pected that travellers, who have to pay attention to some particular 

 and more or less immediate interest, should trouble themselves with 

 geographical questions of a more general character. Thus some mis- 

 conceptions in our general ideas of the physical structure of our conti- 

 nent, produced by some former and premature generalizations of sj-s- 

 tematic geography, are still propagated by maps and books, as well as 

 Congressional railroad speeches, and the influence of these errors on 

 different branches of science, as well as on common life, is important 

 enough to make it worth while to correct them. I am referring here 

 to the prevailing notions of the geographical system of our continent, or 

 the manner in which its mountain chains and table lands are generally 

 believed to be arranged and connected, or separated. As this arrange- 

 ment, together with the geological constitution of the soil, form the 

 principal conditions of the local deviations of climate and of the distri- 

 bution of organic life, it is easy to conceive how the most interesting 

 chapters of physical geography must be affected by any prevailing 

 misconception in that respect. 



A correct knowledge of the whole system of elevations and depres- 

 sions ol the surface of a country can onl}^ be the result of a complete 

 and careful topographical survey and subsequent representation. To 

 execute such a task over a large continent, like that of North America, 

 can only be the work of generations. Even the most advanced States 

 of Europe, small as they are in extent, and almost unlimited as the 

 power of their governments is to expend money for such a purpose, 

 have only lately succeeded in possessing good topographical maps of 

 their territories. But while thus we must resign to our grandchildren 

 the satisfaction of having a clear and correct conception of the ups and 

 downs of the continent we inhabit, we are under the necessit}^ tor our 

 own present wants, to form an approximate idea. Insufficient as the 

 number of our observations must be, and discontented as they are in a 



