a9 r 32 ] 
They Avill both require the same expense of water for lockage. We 
know that two locktiills is the maxinium expense lor raising or lov/- 
ering a boat, and eight minutes are required for its passage through 
a lock of thirty yards in length, ov^- yai-ds in breadth, and 2| yards 
in lift. Sucii a lock will contain 425.64 cubic yards, witliout deduct- 
ing from it the draught of water of the boat, and its passage (at the 
niaxiranm") will tluis consume 853.32 cubic yards, or 8o4 cubic yards 
at most. \Now, if the canal is navigated nine months, or 270 days a. 
year, at ten hours a day, and that tlie locks of the summit level be 
kept in constant operation all that time, they might pass, allowing 
eight minutes for each boat, 20,250 boats, at an expense of water 
equal to 17,293,500 cubic yards, for the nine months, or 1,921.500 
cubic yards a month. This maximum of water for the expense of 
lockage, is 658,980 cubic yards less tirau the minimum which the 
rCvServoirs will receive during that tiuie. 
The expense of water for lockage being 17,295,500 cubic yards, 
and the reservoirs containing 23,689,007 cubic yards, there will re- 
main in reserve to supply tlie losses of tiie summit level, from fiiltra- 
tions and evaporation, 6,395,507 cubic yards. 
The summit level of Deep Creek, extending llj miles in length, 
will require 413,600 cubic yards to fill it: and, supposing that it loses 
by filtrations and evaporation tlie value of its prism every month, or 
nine times in the year, it will expend 3,722,400 cubic yards. The 
profile of its feeder having a supposed area of 10 square yards, and 
a length of lOj miles, it will consume, at the same rate, 1,663,200 
cubic yards. Total consumption for nine months, 5,385.600 cubic 
yards. Retrenching this quantity from the surphis mass of the re- 
servoirs, there will still remain 1.009.907 cubic yards, which, after 
supplying all the waste of lockage, and the losses of the summit level 
from filtrations and evaporation, will serve as an additional supply 
to repair those of the eastern and western branches of the middle 
section. 
The Youghiogeny summit level, extending 21 miles in length, will 
lose from filtrations and evaporation, on tlic same principle, 739,200 
cubic yards a month, (the value of its prism) and 6,652,800 cubic 
yjii'ds in nine months. It wOuld thus absorb the whole snrplus nmss 
of the j'eservoirs, after the waste of lockage, and require a much 
greater expenditure of wat^r than the Deep Creek summit level. 
Thus the important advantage of a greater sup])ly of water, by a 
length shorter by nine miles, of a tunnel shorter by two i\nd a half 
miles, render the Deej) Creek route, sujicrior totiie other; though the 
final surveys only can settle that point, yet at this stage of our ojse- 
rations we would recommend that route in prefei-ence. However, the 
analysis which we have just concluded, is a convincins; proof that a 
canal by either of these routes over the chain of t\\e Allegiianies, 
between the mouths of Savage River a)ul Bear Creek, is })orfectly 
practicable. Tlie total distance from tlie moutli of Savage liiver to 
that of Bear Creek, viil be forty one miles at Jcast, the i-ise frcni! 
the mouth of Savage River to the base-mark, 1,432 feet; and the fall 
