94 ROUTE NEAR THE THIKTY-SECOND PARALLEL. 



grade of 105 feet per mile for five miles, to the next summit, passing the dividing ridge by a tun 

 nel of 4,100 feet in length, and whence, after three miles of light grade, a descent by the grade 

 of 1 05 feet per mile for five miles is made to the valley of Racoon creek, by which, and the 

 valley of the Three Forks creek, the Tygart s Valley river is reached in fourteen miles more, at 

 t4ie Turnpike bridge above described, and 103 miles from Cumberland.&quot; 



The foregoing extract exhibits in a few words the physical obstacles to be overcome. It will 

 be seen that a gradient of 116 feet per mile, both ascending and descending, is required in the 

 aggregate amounting to twenty miles and that in both directions there are also thirteen miles 

 more with gradients exceeding 100 feet per mile.&quot; 



Two important remarks upon the characteristics of the railroad from Valparaiso to Santiago, 

 which will be found in the preceding extract from the report of Allan Campbell, Esq., are equally 

 applicable to the route of the 32d parallel. The first is the favorable character of the approaches 

 to the mountains, by which no numerous secondary ranges and deep intervening valleys are to 

 be crossed, as in the railroads crossing the Alleghany mountains; and the second is, that the line 

 will be free from the evils resulting from snow and ice, which diminish the adhesion of the 

 engine to the rails, and reduce its effective power. Not only are these two remarks fully appli 

 cable to the route of the 32d parallel, but the features of the mountain passes are even more 

 favorable than those of the route discussed by Mr. Campbell. 



There will be more snow and ice in the Tah-ee-chay-pah Pass than in any other on the 

 route of the 32d parallel ; but there is no probability of their being found in sufficient quantity 

 to obstruct in the least the working of the road. In the absence of positive information upon 

 this point, the examination which follows may give some general indication of the climate there. 



The absence of snow and ice in these passes is especially important with the high grades pro 

 posed to be used. These can in every instance, except one, (the San Fernando Pass, over four and 

 perhaps eight miles,) be reduced by side location to grades in use on several principal railroads. But 

 cars are carried safely over grades nearly double the greatest here proposed for temporary use, 

 and the increased cost of employing additional engines over these portions of the road is not in the 

 least serious, compared with the additional expense and loss of time required to secure easier 

 gradients. 



The winter temperature of San Francisco is 50 Fahrenheit. The Tah-ee-chay-pah Pass is 

 about 3 south of San Francisco, and at the same level would have a winter temperature of 53. 

 The elevation being 4,000 feet, would give, by the usual rule, a temperature from 13 to 15 

 lower, or a mean winter temperature of 40 or 38. It is probable, however, that it is some 

 what lower than this, which is about the mean winter temperature of Fort Monroe, Old Point 

 Comfort, Chesapeake bay. The mean winter temperature of Charleston is 50, and that of the 

 summit elevation of the railroad route westward to the Mississippi, 1,400 feet above the sea, 

 is about 45. 



The mean winter temperature of Fort McHenry, Baltimore harbor, is 32.7; that of the sum 

 mit elevation of the Baltimore and Ohio railroad, 2,600 feet above the sea, should be about 24, 

 which is 14 or 16 lower than that obtained for the Tah-ee-chay-pah Pass. 



There is deep snow in the Tejon Pass, but from the open character of the Tah-ee-chay-pah 

 Pass, and its greater distance from the junction of the two chains of mountains, the snow and ice 

 found there will not probably be seriously disadvantageous. 



GENERAL REVIEW. 



Among the general considerations which determine the position of the route near the 32d 

 parallel, the most prominent are the low elevation of the mountain passes, and their favorable 

 topographical features, as well as those of the table-lands, embracing over 1,000 miles of the 

 route; the favorable character of the surface generally, by which the most costly item of con 

 struction in railroads, the formation of the road-bed, is in a great measure avoided ; the short- 



