34 
CONCLUSION OF THE OFFICIAL REVIEW, ETC. 
traversed by Captain Pope’s party. Tbe route near the 32d parallel, between the Pecos and 
the Rio Grande, was re-surveyed, and the proposed railroad line modified and improved. The 
Guadalupe mountains were examined for 75 miles, from the southern high peak to the Lympia 
mountains, but no pass found so favorable as that now traversed by the road, (the Guadalupe 
pass.) A new examination of this pass has led Captain Pope to the conclusion that the 
maximum grade, in following it, may be reduced from 108 feet to less than 80 feet per mile. 
Water is to be found at intervals of less than two miles from this pass, nearly to Ojo del Cuerbo. 
Forests of pine line the summits of the range for 30 miles north of the pass, and are also found 
upon the adjacent mountain chains. 
Between Ojo del Cuerbo and El Paso two new lines have been surveyed; the first passing the 
Waco mountains, with a maximum grade of 60 feet, and with a summit level 200 feet lower 
than that of the route pursued in 1854; the second line lengthening the route 10 miles, but 
reducing the maximum grade to 40 feet, and avoiding the Waco mountains. 
It is reported by Captain Pope that an examination of the Llano Estacado has developed an 
unfailing source of fuel in the mezquite root which exists there in great abundance. The wood 
thus furnished is of a hard and compact structure, and varies in size from three to six inches in 
diameter, affording a superior charcoal. Specimens of the wood and charcoal have been brought 
in for examination. 
A topographical as well as geological survey was made of the Jornada del Muerto and the 
country between the Rio Grande and the Mimbres, and the mines of the Organ mountains 
examined. 
Astronomical positions were determined at different points along the routes traversed, and 
from data collected by many months’ observations, a point was fixed in longitude near the 
intersection of the thirty-second parallel with the Pecos river, and a stone monument erected to 
mark its position. 
Elaborate magnetic and meteorological observations were made during the time that the party 
was in the field. These observations embraced a period including the different seasons of the 
year, and extended over lines connecting the low lands near the Gulf of Mexico with the high 
table lands of the interior. 
The party of Captain Pope has recently returned to Washington, and is now employed in 
preparing detailed reports of the operations that have been conducted under his direction. 
The geological and other sub-reports which accompany the reports of the various surveys will 
form the subject of future notice. They contain material valuable in its bearing upon the con¬ 
struction and working of a railroad, and in a scientific point of view. They are merely referred 
to here; the object now being to present only those general topographical features which will 
be looked for with most interest, as chiefly solving the question of the comparative practicability 
of the different routes. 
Certain maps, drawings, and scientific papers that were still in progress at the date of my 
communication of November 29, 1855, and which are intended to form part of the reports 
submitted by the first exploring parties, have been, with one exception, completed. 
Very respectfully, your obedient servant, 
A. A. HUMPHREYS, 
Captain Topographical Engineers, 
In charge of Office of P. B. B. Exp. and Surveys. 
Hon. Jefferson Davis, 
Secretary of War. 
