107 [ 237 ] 



steamboat of the American Fur Company of St. Louis, upon which we 

 were, which did not run in the night, but made very long day trips, I 

 divided the work of these daily sketches, of which 1 have spoken, into 

 three portions. 1 charged myself with a part commencing at daybreak, 

 and continuing uniil 9 o'clock a. m. ; Lieut. Fremont succeeded me un- 

 til 2 p. m. ; and Mr. Geyer had the rest of the day. It is from these 

 daily sketches that we protracted the map, after the courses and distances 

 had been corrected by the observed geographical positions. All the points 

 known by their latitudes and longitudes being laid down at first upon the 

 map, these points determine the spaces within which must necessarily 

 quadrate all the other points and details procured, directly or indirectly ; 

 and in relation to which, means of comparison and control always present 

 themselves naturally : thus assuring a sufficient exactitude for placing 

 points that may not have been actually observed. There remains, then, 

 nothing indeterminate but the form and dimensions of detail-objects, such 

 as lakes, the detours and sinuosities of rivers ; things of which we can 

 only come to have precise knowledge by systematic surveys, which it will 

 be the business of civilized men to establish in proportion as they people the 

 country. 



It is easy, upon inspecting the map, to recognise those portions of which 

 a reconnoissance or a survey has been made, and such as have been laid 

 down from information merely. Use has been made of the public land 

 surveys, which have been liberally furnished us by the land offices, 

 wjierever they touched our ground, in Missouri, Illinois, Wisconsin, and 

 Iowa. With regard to the river surveys, which are our own work, I may 

 mention what follows. 



The Missouri has been reconnoitred, with care, for a distance of 1,253 

 miles from its junction with the Mississippi, as far as Fort Pierre Chou- 

 teau. All its accidents, physical and geographical, which the scale of 

 the map allowed, have been there expressed. In respect to this, it is 

 much to be desired that the work giving account of the expedition of 

 Lewis and Clarke, now entirely out of print, could have a second edi- 

 tion. This work does not so much recommend itself by the exactness 

 of its survey and astronomical observations ; the authors made no pre- 

 tension of that kind ; but it may be considered as one of the greatest, 

 most difficult, and at the same time most happy geographical enterprises 

 that have ever been undertaken, which concerns the honor of the nation, 

 and which merits that of a second edition, by the truth, accuracy, and con- 

 ciseness of its descriptions. These descriptions, in my judgment and ex- 

 perience, will serve for comparisons useful to geography. They will even 

 come, hereafter, to be useful for the physical history of the mighty Mis- 

 souri ; the effects of which, in the valley it passes through, serve as a 

 standard in investigating the ros^inie of large rivers, and in perfecting the 

 hydrographic theory of their flow. If this step were taken, advantage 

 might also be had in correcting a number of errors, which detract from 

 the first edition, and to introduce an addition from the manuscripts of Gen- 

 eral Clarke, which I think were not consulted at the time. I know no 

 persons who could better be employed upon the publication of a second 

 edition than the sons of this distinguished and modest traveller, aided, if 

 necessary, by the general government. 



The St. Peter's river received the first rectifications of its direction 

 from the second expedition of Major (now Lieutenant Colonel) Long. 



