botany
was made in varieties of plants, flowers, shrubs, trees and grasses,
and rocks and earths, which were enumerated." The second expedition
of May, 1843, was upon a larger scale, and it was not completed until
the month of July, 1844. He was directed to extend his survey across
the continent, on the line of travel between the State of Missouri and
the tide-water region of the Columbia.

In its execution, much more ground was covered than had been
contemplated in the order. Fremont was the first person that visited
the basin of the Great Salt Lake who was able to furnish a scientific
and accurate description of the region. Von Humboldt, in his work
entitled "Aspects of Nature" (pp. 32-34) has given a summary of the
results reached by Fremont in his first and second expeditions, as
follows:

"Fremont's map and geographical researches embrace the immense tract
of land extending from the confluence of the Kansas River with the
Missouri to the cataracts of the Columbia, and the missions of Santa
Barbara and the Pueblo de los Angeles in New California, presenting a
space amounting to 28 degrees of longitude (about 1,300 miles) between
the 34th and 35th parallels of north latitude. Four hundred points
have been hypsometrically determined by barometrical measurements, and
for the most part astronomically; so that it has been rendered possible
to delineate the profile above the sea's level of a tract of land
measuring 3,600 miles, with all its inflections, extending from the
north of Kansas to Fort Vancouver and to the coasts of the South Sea
(almost 720 miles more than the distance from Madrid to Tobolsk). As
I believe I was the first who attempted to represent, in geognostic
profile, the configuration of Mexico, and the Cordilleras of South
America,--for the half-perspective projections of the Siberian
traveler, the Abbe Chappe* were based upon mere, and for the most part
on very inaccurate, estimates of the falls of rivers,--it has afforded
me special satisfaction to there find the graphical method of
representing the earth's configuration in a vertical direction, that
is, the elevation of a solid over fluid parts, achieved on so vast a
scale. In the mean latitude of 37 degrees to 43 degrees, the Rocky
Mountains present, besides the great snow-crowned summits, whose height
may be compared to that of the Peak of Teneriffe, elevated plateaux of
an extent scarcely to be met with in any other part of the world, and