112 ۱ GENERAL REMARKS ON THE TOPOGRAPHY. 
length. It must be allowed that all that part of the west of North America is still but very 
imperfectly known.’ 
The explorations of Lewis and Clarke proved that the Tacouche Teche did not empty into 
the Gulf of California, and that it was probably the source of the Columbia. Without con- 
sidering the character of the pass of the Columbia river through the Cascade range, the belief 
now became general that the overland route in this latitude crossed but one summit, and was 
therefore more favorable than any other. This erroneous idea, with some, still prevails. 
The idea of rivers traversing great mountain chains, now known to be so common in the 
mountains west of the Mississippi, was so repugnant to the opinions of even philosophers in 
earlier times, that we find Humboldt saying, ‘‘every geographer who carefully compares 
Mackenzie’s map with Vancouver’s will be astonished that the Columbia, in descending from 
the Stony mountains, which we cannot help considering as a prolongation of the Andes of 
Mexico, should traverse the chains of mountains which approach the shore of the great ocean, 
whose principal summits are Mount St. Helen and Mount Rainier.’’ 
In reference to the supplying a want of facts by theories, Humboldt makes the following 
remarks: ‘‘It is a false application of the principles of hydrography when geographers 
attempt to determine the chains of mountains in countries of which they suppose they know 
the course of rivers. They suppose that two great basins of water can only be separated by 
great elevations, or that a considerable river can only change its direction where a group of 
mountains opposes its course ; they forget that frequently, either on account of the nature of 
the rocks, or on account of the inclination of the strata, the most elevated levels give rise to 
no river, while the sources of the most considerable rivers are distant from the high chains of 
mountains. Hence the attempts which have been hitherto made to construct maps from 
theoretical ideas have never been very successful. For the true configuration of the earth is 
so much the more difficult to be discovered, as the pelagic currents, and the greater number 
of the rivers, which have changed the surface of the globe, have totally disappeared. The 
most perfect acquaintance with those which have existed, and those which actually exist in our 
day, might instruct us as to the slope of the valleys, but by no means as to the absolute height 
of the mountains, or the position of their chains.’’ 
The distinguished explorers, Lewis and Clarke, having determined that the Columbia river 
broke through the Cascade range, considered, from the size of the Willamette at its mouth, 
that it also broke through this chain, having its source in the Rocky mountains, near the posi- 
tion of Great Salt lake. We then see the American maps representing mountains surrounding 
the valleys of the Columbia and Colorado, and separating them from that of the San Joaquin 
and Sacramento. On the English maps of that date, the Sierra Nevada is not represented, and 
two or three great rivers are made to flow from large lakes in the interior to the Pacific; 
nearly all of their — making false ee of the pang of ire laid 
down by Humboldt. 
The first map which ESOS these rivers and lakes sorea was that of کب‎ Bonne- 
ville, of which I have given a reduced copy. There we see the Great Salt lake and Bear 
river and Utah lake forming one pasin; to the west lies the Mary or Ogden’s river, with its 
lakes forming another enclosed basin; the San Joaquin and Sacramento rivers in their right | 
position; and the Willamette reduced to its proper length. The positions given on this map 
are not geographically correct, nor are their many mountains indicated ; but it gives the first 
