Explorations and Surveys for the Pacific Railroad. 93 



The sum of the ascents and descents given for the various 

 routes does not take into consideration those minor undulations 

 which sometimes largely increase the aggregate. I think it prob- 

 able that when detailed surveys are made, it will be found that 

 this sum for the route near the 47th parallel will be more in- 

 creased than those for the other routes, and that the sum for the 

 route near the 32 d parallel will be less increased than the others. 



The equated lengths corresponding to these sums may give 

 erroneous impressions. If the loads to be habitually carried over 

 the roads are within the power of the engines over the greatest 

 grades proposed, then the sums of ascents and descents really 

 have little meaning or value. The wear and tear of rail and 

 machinery and consumption of fuel would be somewhat greater 

 on the road having the largest sum, but the difference would not 

 be worth taking into account, unless there was an equality in all 

 other respects between the routes. 



If there are some grades so steep as to require the division of 

 the loads habitually carried over other portions, the cost of the 

 extra locomotives and of working them over those portions will 

 show the extent of the disadvantage and yearly cost. 



So far as any estimate has been made in this report of the 

 amount of work to be done on the roads, these sums of ascents 

 and descents have little practical value, since those portions of the 

 routes have been indicated where it may be considered advisable 

 to use steep natural slopes with extra engines, to expedite the 

 completion of the road and save expensive road-bed preparation. 

 With a full equipment and heavy freight business, the sum of 

 ascents and descents becomes important. 



The advantages and disadvantages of the several routes may 

 be briefly recapitulated, as follows : 



1. Route near the forty-seventh and forty-ninth parallels. — The 

 advantages of this route are — its low profile, which is important 

 in relation to climate ; its easy grades, and small amount of as- 

 cents and descents, both important if the road should be devel- 

 oped to its full working power ; the great extension west of the 

 prairie lands ; in the supplies of timber over the western half of 

 the route ; the facilities which the Columbia river and its tribu- 

 taries, and the Missouri, will afford to the construction of the 

 road ; in the short distance from the Mississippi to a seaport of 

 the Pacific, (1,864 miles to Vancouver ;) in the western terminus 

 of the road on Puget Sound being nearer to the ports of Asia 

 than the termini of the other routes ; in the proximity of the 

 eastern terminus to Lake Superior, from which a continuous navi- 

 gation for sea-going vessels extends to the Atlantic ocean ; and in 

 the existence of coal on Puget Sound. 



Its disadvantages are — the difficult and costly construction, 

 including a long tunnel, through a mountain region of 550 miles, 

 (comprising 90 miles on the Columbia river ;) the delay in con- 



