xxxviii Astronomical and Meteorological Records^ £ffc. 



of the secondary base, most remote from the peak, was S° 41' 15", 

 corrected also for index error of sextant. The final result of these 

 observations, gives for the height of the peak above the plain in which 

 tiie observations were made. 8507} feet. 



In order to ascertain with precision, tlie angle of elevation of the 

 summit of the peak, an artificial horizon of water was employed, and 

 the double angle of elevation observed. The angle of elevation as it 

 stands corrected for refraction, is 3° 39' 26". The estimate as above 

 gives the height of the peak above the true level of the place of ob- 

 servation, no correction having been made for the spherical figure of 

 the earth. 



Allowing the pei-pendicular fall of the river Platte, from the moun- 

 tains to its mouth, to be on an average nineteen inches per mile, 

 (which appears reasonable from the rapidity of its current compared 

 with that of the Missouri,) the fall of the Missouri from the place 

 where it receives the Platte to its mouth, to be 16 inches per mile, 

 which agrees with the result from leveling at Engineer Cantonment — 

 and that of the Mississippi from the mouth of the Missouri to the Gulf 

 of Mexico to be 12 inches per mile, it would give for the height of the 

 Platte at the base of the mountains, say at the place of the above ob- 

 servations, 3000 feet above the level of the ocean, and consequently 

 the height of James's Peak would be 11507| above the same level. 



This mountain was clothed in snow for a considerable distance be- 

 low its summit, when the exploring party visited it, in the middle of 

 July, and at the same time they experienced excessive heat* at its base. 



Observations made on the drkansa, at our camp, situated about twenty- 

 five miles below the point where the river issues from the viountains. 



Equal altitudes of Sun to find error of watch, at nootu 



Error of Watch. 



July 17, 1820. 

 July 17, 1820. 



Time from Noon, 

 A. M. 



3" 27' 17" 

 3 25 58 

 S 24 36 



Time fi-om Noon, 

 P.M. 



3" 08' 35 

 3 07 15 

 3 05 54 



'■} 



Meridian double altitude of 



Antares 

 Index error — 3' 22". Latitude 



deduced 



15' 03" slow- 

 Mean time. 



51° 28' 



38 18 19 N. 



Jlmean of eight lunar observations. Distance of nearest limbs of sun 

 and moon for calculating the longitude. 



July 17, 1820. 



