106 COMPARISON OF THE ROUTES. 
IV. ROUTE NEAR THE THIRTY-FIFTH PARALLEL. 
The advantages of this route consist in water and fuel being generally less scanty than on the 
others, excepting that of the 47th and 49th parellels; ina better supply of timber west of the Rio 
Grande; in the greater mildness of the winter than on the routes north of it; in the temperate 
character of the summer over nearly the whole route; in no tunnels being required on the Rocky 
mountain passes, and none on the route to San Francisco by the Tah-ee-chay-pah Pass; in the 
probability of the existence of coal-fields in the middle of the route; and in the assistance that 
the population of New Mexico and the Mexican provinces of Chihuahua and Sonora may give in 
constructing and supporting the road. 
The disadvantages are—its greater length from the Mississippi to the Pacific than the route south 
of it; the apparently rough and broken character of the country through which much of it lies ; 
its much greater cost, and the greater number of ascents and descents, the sum of which is the 
greatest of the four routes, and which would become seriously objectionable should the full work- 
ing power of the road be developed. 
V. ROUTE NEAR THE THIRTY-SECOND PARALLEL. 
Its advantages are—the short distance from the eastern terminus to a Pacific port (1,618 
miles ;) the small cost of the road, it being to a Pacific port less than two thirds of the cost of the 
cheapest of the other routes, and to San Francisco $20,000,000 less than the least of the others, 
(the cheapness of construction being due to the location of the route upon more than 1,000 miles 
of table-lands and plains;) in the open and otherwise favorable features of the mountain passes3;- 
the lowness of their summits ; in their natural slopes admitting of use without extensive and costly 
preparation; in the mild winters and temperate summers of all the route except that portion of 
the Gila and Colorado desert where, for 350 miles, labor in the open air must be suspended for 
three months of the year; in there being no reason to apprehend difficulties, itnpediments, delays, 
and dangers from snow and ice ; in the coal-fields of the Brazos; and in the aid that the population 
of New Mexico and the provinces of Chihuahua and Sonora may give in constructing and 
supporting the road. 
Its disadvantages are—the cost of construction of a portion between the Pecos and Rio Grande ; 
the circuitous route to San Francisco from the plains of Los Angelos, which, unless further ex- 
plorations determine a more direct route, requires a second crossing of the coast range, and a 
passage through the Sierra Nevada; in the sum of ascents and descents being the next largest 
after that of the 35th parallel, the extent of which objection depends upon the amount of business 
to be done on the road; and, finally, in the scanty supply of water and fuel on the route. 
