JOHN C. FREMONT. 423 



entific materials that had been collected during the expedition, and in 

 the preparation of a map and a report. In 1842 he was directed by 

 Colonel Abert, the Chief of the Topographical Corps, to make an 

 exploration of the Northwestern frontier of the State of Missouri to 

 the Rocky Mountains, and with special reference to an examination of 

 what was known as the South Pass in those mountains. This expedi- 

 tion was on a small scale, consisting of twenty-one men only, most of 

 whom were of French extraction. In this expedition, he traced the 

 waters of the Platte to the South Pass, which he reached the 8th of 

 August. It was stated by Dr. Linn, then a Senator from the State of 

 Missouri, that " over the whole course of the road barometrical obser- 

 vations were made by Mr. Fremont to ascertain the elevations both of 

 the plains and of the mountains, astronomical observations were made 

 to ascertain latitudes and longitudes, the face of the country was 

 marked as arable or sterile, the facility of travelling and the practica- 

 bility of routes noted, the grand features of nature described and some 

 represented in drawings, military positions indicated, and a large contri- 

 bution to geology and botany was made in varieties of plants, flowers, 

 shrubs, trees, and grasses, and rocks and earths, which were enumer- 

 ated." 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 fur- 

 nish a scientific and accurate description of the region. Von Hum- 

 boldt, 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 1,360 miles) between 

 the 31th and 45th 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 



