CONTENTS. 
CHAPTER IX. 
Discussion of barometric observations and tables of altitudes and distances of the line explored from West- 
port, Mo., to Great Salt Lake City, Utah Territory ; also, tables of simultaneous observations in, and 
data for profiles of, the mountain passes of the line —1853. 
Page. 
I.—Introduction to, and corrections applied in, barometric computations.—Table for horary corrections of obser¬ 
vations.—Corrections for extreme air temperatures.—Comparison of field barometers with Dr. Engelmann’s 
barometer at St. Louis, Missouri, both before and subsequent to the surveys.—Table of monthly mean obser¬ 
vations at St. Louis, by Dr. Engelmann. 89 
II.—Barometric and meteorological observations, and table of altitudes and distances, for the profile of the line of 
survey from Westport to Great Salt Lake City.-. 94 
III. —Data for profile of Roubideau’s Pass..... 108 
IV. —Simultaneous meteorological observations at Coochetopa Pass. 108 
V. —Observations for a tunnel or deep cut in the Coochetopa Pass, allowing fifty yards as the width of the ridge at top 108 
TV.—Table IV resumed—. 108 
VI. —Data for the profile of the Coochetopa Pass, and declivities near its summit. 109 
VII. —Simultaneous meteorological observations at the pass and on the route followed across the Wahsatch range ... 110 
VIII. —Data for the profile of the route followed across the Wahsatch mountains. Ill 
CHAPTER X. 
Geographical positions and distances travelled' on the line of exploration from Westport, Mo., to Great 
Salt Lake City— 1853. 
I. —Letter from Mr. S. Homans, in charge of astronomical department. 113 
II. —Table of geographical positions from Westport, Missouri, to Great Salt Lake City, Utah. 113 
III.—Table of distances travelled, including those from point to point at which barometrical observations were made,- 
on the route from Westport, Missouri, to Great Salt Lake City.-. 115 
JV.—Table of distances travelled on the line followed from Westport, Missouri, via Fort Riley, Kansas Territory, 
to Walnut creek. 118 
APPENDIX A. 
Letters relating to the progress of the survey of the route near the 38 th and 39 th parallels, in charge of 
Captain Gunnison. 
I.—Letter dated June 20,1853, Camp, Shawnee Reservation, from Captain Gunnison to the Secretary of War, 
indicating the line which will be followed in crossing the Plains. 119 
n.—Letter dated August 22,1853, Camp, Utah creek, near Fort Massachusetts, from Captain Gunnison to the 
Secretary of War, reporting the progress of the survey... 119 
III. —Letter dated August 22,1853, Camp, Utah creek, near Fort Massachusetts, from Captain Gunnison to Colonel 
J. J. Abert, reporting the progress of the survey. 120 
IV. —Letter dated September 20, 1853, Camp 70, Grand river, Utah Territory, from Captain Gunnison to Colonel 
J. J. Abert, reporting the progress of the survey. 121 
V.—Letter dated September 23,1853, Camp 72, Bitter creek, Utah Territory, from Captain Gunnison to Colonel 
J. J. Abert, forwarding a rude copy of the field-work of the survey. 123 
VI.—Letter dated October 29,1853, Camp, near Fillmore, Utah Territory, from Lieutenant Beckwith to Colonel J. 
J. Abert, reporting the progress of the survey, requesting instructions, and indicating future operations. 123 
APPENDIX B. 
Lists and explanations of the maps, sections, and illustrations of the reports of the explorations of Captain 
Gunnison in 1853, and of Lieutenant Beckwith in 1854.— -. 125 
