[82] U 
report Oil tli« line of location, togetiicr with sin estimate of expense, 
may yet be made, inulcr existing ciirumstances, without impropriety^ 
The whole line naturally tliAides itself into two sections: 
The j'hsf extends from the tide to the foot of the Alleghany, where 
the Savage, a hrancli of tlie Potomac, breaks through the Great Back 
Bone, as this mountain is called to distinguish it from another ranga 
more west. This section is computed to be 210 miles. 
The second section extends from the month of Savage to the mouth 
of Bear creek, a distance, varying according to the line which may 
be hiiaily a<h)pted. of from 34 to 62 miles. 
The ik'trd section extends from the mouth of Bear creek to the city 
of Piitsburg, 326 to 350 miles, according to the line which may be 
found nu)st si! i table. 
The canal between the Ohio and the Lake naturally divides into 
two sections — the eouthern and northern — the first about 70, the lat- 
ter about 30 miles. 
The most i-emarkablc features of the eastern or first section may be 
thus briefly described: 
The Potomac passes through the Blue Ridge, near Harper's Ferry, 
at an elevation of about two hundred feet above tide. This height 
gives a command of the ground eastward, and may enable the engi- 
licer to choose the ground most convenient to pass the ^vhole of the 
Great Falls. 
Immediately below the junction of the Shenandoali, which is above 
the Blue Ridge, the river is contracted by the hills, which will con- 
fine the w orks to a narrow com])ass. Ledges in the stream transverse 
to its course, appear well situated to si!]>p(jrt a dam necessary to form 
a basin, at once to accommodate tiic village with a good landing, the 
trade of tlie Shcnan(h)ah with access to the canal, and for the purpose 
of siipijlying w ater to tlie eastern levels; but no place on this level pre- 
sents more complicated circumstances, or refjuii-es more to be studied. 
The valley of the Potomac, as we ascend it to Cumberland, exhi- 
bits favorable gi-ound — genei'ally extensive intervales and gentle ac- 
cli^ities, with few exceptions of abrupt hills. A few^ aqueducts wil! 
be required, and above Cumberland they must be frequent; for £8 
miles, it will be often a question of expediency and calculation, whe- 
ther to cross or recross, or rather carry the canal some di^^tance 
tlirough rock. It is not, however, improbable that a modern improve- 
ment in aqueducts will diminish their expense, so as to make thai 
metjiod less objectionable. 
Tiie Potomac, in June, was found to deliver 220 cubic feet per se- 
cond above Savage, and t'se Savage 76 cubic feet; on the 17th of Sep- 
tember, iof'-/jy -,,j(5 ijje Savace 35.613. The survey executed as far 
10 ♦-^ * 
down as Ciuuberland, has ascertained the descent to that place to be 
327 feet 6 inches, the distance 28 miles. 
Tlie second or summit section follows up the Savage through the 
Alleghany mountain, and at the distance of five and a half miles, 
readies the Crabtroe branch, coming in from the southwest. Thus 
far, altliougii the hills rise high and sleep, there are narrow bottom'! 
