28 ROUTE NEAR THE THIRTY-SECOND PARALLEL. 
The natural slopes of the three passes just considered are within the power of a 30-ton engine 
witha load of 200 passengers, each with 100 pounds of baggage. 
Supposing 20-ton engines used, and that they carried the maximum loads adapted to the other 
portions of the road, where the greatest grades are 40 feet to the mile, it would be necessary 
to divide this load into three parts to pass a grade of 150 feet per mile; and the grades being 
brought to that, its disadvantage consists in the expense of two additional engines worked 
through the passes. 
From the head of the Tulares valley, the navigable waters of the Bay of San Francisco may 
be reached in several ways. 
The eastern side of the Tulares and San Joaquin valleys is intersected by numerous streams 
from the Sierra Nevada. The western is bounded by the Coast chain, and has few streams. 
That part of the Tulares valley between Kern and San Joaquin rivers, a space of 150 miles, 
having a soft alluvial soil, is, at certain seasons, miry; a road, therefore, extending through it, 
should keep near the foot-slopes of the mountains. From the Tah-ee-chay-pah Pass to the best 
point of crossing Kern river, 214 miles, the route passes over a dry, dusty plain, destitute 
of water and fuel, the soil of which is not well constituted for fertility. 
From the crossing of Kern river to the second crossing of the San Joaquin, near Grayson’s, 
the numerous river-beds or bottoms should be crossed on piles, the spaces varying from 50 to 
300 feet—the greatest width to be spanned not exceeding 100 feet. From Tah-ee-chay-pah Pass 
to the Straits of Martinez, the location distance would be 288 miles. The most direct route 
to San Francisco from the Tah-ee-chay-pah Pass will be found through one of the passes known 
to exist inthe mountain range separating the Tulares and San Joaquin valleys from those of 
the Salinas and San José rivers. The distance through it is about 10 miles; the elevation 
of the passes about 600 feet. From Tah-ee-chay-pah Pass the route should cross to the western 
side of the Tulares valley, around the head of the lakes, and enter the Salinas valley as soon as 
practicable. 
The soil of the Tulares valley, north of Kern river, and of the San Joaquin valley, is well 
constituted for fertility, and needs merely the proper amount of water to be highly productive. 
Sufficient water and fuel for working parties can be found at convenient distances on this section, 
(excepting where it crosses the Great Basin, and approaching Kern river; the amount of 
deficiency on these portions having been already given.) Lumber and good building-stone 
are found at various points in the mountains, accessible from their foot-slopes. For fuel for 
locomotives, the coal of Puget sound and Vancouver’s island must probably be depended upon. 
The topographical features of this extension of the route are, with the exception of the mount- 
ains, favorable to cheap construction. The mountain passes are likewise of a favorable character, 
their only objectionable feature being their high grades. The nature and extent of this objection 
has been already stated, and, it is seen, 1s not serious. 
From Fulton to San Francisco the distance is 2,039 miles; the sum of the ascents and descents 
42,008 feet, which is equivalent to 795 miles; and the equated length of the road is 2,834 
miles; the estimated cost is $93,120,000. 
To Lieut. Williamson, assisted by Lieut. Parke, was intrusted the survey of a route from 
the Bay of San Francisco to the junction of the Gila and Colorado rivers, connecting with the 
ports of San Pedro and San Diego on the one side, and on the other with the most practicable 
mountain passes. His work has been thoroughly and handsomely executed, presenting much 
new and valuable information of the mountain passes on the southern portion of the Sierra 
Nevada and Coast range. The geological examination, made under his orders, is highly 
creditable and instructive. 
The examination of the middle section of the route of the 32d parallel, by Lieut. Parke, 
was very thorough, and highly creditable, though executed with small means; and his report 
very satisfactorily exhibits the character and essential features of the country over which he 
passed. The scientific labors of the boundary survey, which had been previously performed in 
