OF THE BOUNDARY COMMISSION. 5A5 
and drawings were made by Henry C. Pratt, Hsq., 
draughtsman and artist to the Commission, which ex- 
hibit the characteristic features of the regions visited, 
including the mountain passes, outlines of the mountain 
chains as they presented themselves to us from different 
points, etc., etc.; and convey a far more comprehen- 
sive idea of the physical geography of the zone of 
country traversed than can be given in any written 
description. To this department of our work I de- 
voted some of my leisure moments, particularly in jour- 
neys on which I was not accompanied by Mr. Pratt. 
Of the labors of the parties on the Rio Grande or 
Bravo Del Norte, I have now to speak. These parties 
were all placed by me under charge of Brevet Lieut. 
Col. J. D. Graham, of the Topographical Engineers, 
Principal Astronomer and Head of the Topographical 
Scientific Corps, a programme of which will be found 
in Appendix F. This officer was detailed for ser- 
vice on the Boundary Survey, on the 23d October, 
1850, and reached the Head Quarters of the Commis- 
sion at the Copper Mines, New Mexico, the nearest 
point to our field of operations, on the 2d of August, 
1851. He was recalled by the Hon. Alex. H. H. Stu- 
art, Secretary of the Interior, on the 13th of Septem- — 
ber of the same year; and on the same day, Brevet 
Major W. H. Emory was appointed to his place. The 
latter reached El Paso on the 25th of November, and 
delivered the order of recall to his predecessor. 
Major Emory, in his letter to me under date of 
June Ist, 1852,* informing me of the work performed 
* Senate Document, No. 6, Special Session, 1853, p. 42. 
VOL. II.—35 
