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EXTRACTS FROM [PRELIMINARY] REPORT. 
CHAPTER XL 
CONCLUDING REMARKS. 
The concluding report will describe many new species both of plants and animals. We will 
also be enabled to present to the department a complete geological and mineralogical section 
from the Mississippi river through the Rocky Mountains, the Sierra Madre, the chains east of Rio 
Colorado and the Sierra Nevada, to the Pacific ocean. This was a field new to science, and our 
geologist, with abundant experience both in Europe and America, was well fitted for this explora¬ 
tion. The various formations have been developed, the ages of mountain chains established, and 
the position of mineral regions determined. 
Specimens of rock for building material have been procured in order to test the qualities of 
hardness, durability, and general adaption to the purposes of construction. 
Sketches have been obtained of landscapes, as well as of animals, plants, Indian portraits, 
scenes, ancient paintings, hieroglyphics, and curiosities. 
An extensive series of meteorological and magnetic observations have been obtained for 
climatological investigations, and for the determination of the elements of inclination, declina¬ 
tion, and intensity, over the region traversed. They are necessarily deferred to the conclusion 
of our operations. 
In relation to this subject I would, however, refer to the accompanying climatological map, 
with remarks prepared by L. Blodget, esq., from observations collected by the Smithsonian 
Institution in connexion with those made during the survey. It will be perceived that the 
parallel of 35° is particularly favored by rain. The valley of the Canadian, the Zufii region, 
the vicinity of the San Francisco mountains, and the Aquarius range, have evidently a large 
supply of precipitated moisture. The arid deserts between the Mississippi and the Pacific coast 
are here contracted to their narrowest limits ; consequently, upon this route there are more 
springs, more streams, and more woodland, than can be found upon lines I have traversed 
further south. 
The gradients found to be practicable are marked upon the profile. 
Curves of less radius than half a mile occur only in the Cajon Pass, and on Canon and Big 
Sandy creeks, where they break through low mountain chains of metamorphic rock. There are 
there a few sharp turns, and it would be necessary in one place to tunnel through a point per¬ 
haps four or five hundred feet in thickness to attain a radius of one thousand feet. The few 
other bad places would require cutting, as upon the Hudson River railroad, at the edge of the 
blutfs. But already it has been mentioned that the Cajon Pass is considered only as the last resort 
for an entrance to the Pacific coast; and the firm belief that, by ascending the main eastern 
branch of Bill Williams’ fork, both Canon Creek and Big Sandy may be avoided. 
The principal bridges would be required at Rio Pecos, Rio Del Norte, Canon Creek, and Rio 
Colorado ; all others are of minor importance. The first and second have already been mentioned. . 
Canon Creek, I doubt not, may be avoided by following the main eastern branch of Bill Williams’ 
fork. Should it prove otherwise, it would be necessary to throw arches across the stream at 
three several points where canons occur. The best of stone for this purpose is abundant in the 
vicinity. Two excellent points for crossing the Colorado occur—one at the canon immediately 
below the junction of Bill Williams’ fork, the other where rocky spurs impinge upon the river 
below the Mojave villages. The width of the stream between natural abutments, at these points, 
does not exceed two hundred and fifty yards. 
Our line could in many places be made straighter and shorter, should wells be dug at proper 
points ; either common or artesian wells would undoubtedly be successful throughout the whole 
distance from Fort Smith to Rio Pecos. Between that stream and the del Norte the strata are 
too much broken to be depended upon. Westward there are points where they could probably 
be made available. Rio Puerco, which at some seasons, in places, sinks, could doubtless be 
