The Mountains of Western North America. 83 
mind, is a great desideratum. It has in part been attempted at 
various times, but as yet unsuccessfully from the want of suffi- 
cient information; the theorist’s idea being often proved to be 
wrong by new discoveries almost as soon as altered? we initial 
“The publication of the Pacific Railroad maps will probably 
change some of the former ideas of these mountains, and give 
rise to new speculations as to their directions, equivalents, and 
connexions of different parts. Every one knows how easy it is 
to generalize ideas where facts are few, and in accordance with 
this, those who have travelled most in the region have theorized 
the least, having seen the immensity of the subject and the dif- 
ficulties which must be overcome to comprehend it. Those 
who have investigated merely the travels of others, have had 
only the imperfect representations of the latter on which to the- 
orize. 
__ ‘It may not be inappropriate here to give some of the general 
ideas which have successivély prevailed in regard to these moun- 
ns, 
“In the earlier periods of North American discovery it was 
known that there were mountains in the interior at its northern 
and southern parts, and rivers flowing from them to the two 
great oceans east and west. It was natural to connect these 
mountains by hypothesis, and to consider them as one great 
chain, separating the sources of these streams. Such an idea 
prevailed at the time of Humboldt’s New Spain. Even now 
many well informed persons consider that a road has but one 
mountain summit to cross from the Mississippi river to the Pa- 
¢ Ucean, 
“When, after the publication of the charts of Vancouver, 
map makers became aware of the extent of the mountains near 
the Pacific coast, nothing seemed more natural than to suppose 
two great mountain chains—one near the Pacific and one in the 
interior. If this theory were true, we should find a great longi- 
tudinal valley between the ranges similar to that ———* e 
iuterlor mountains from the Alleghanies, and we should have 
but two mountain summits to pass between the Mississippi and 
the Pacific. This idea is practically as erroneous as that of one 
Summit, although it still prevails. Such a inent place did 
this longitudinal valle hold, in the opinions of geographers of 
earlier times, that we find in Humboldt’s New Spain: ‘M. mete 
the T 
ofan enormous length. It must be allowed that all that part of 
on, rhe explorations of Lewis and Clarke proved that the Ta- 
Couche Teche did not empty into the Gulf of California, and 
