The Rock Island Argus. (Rock Island, Ill.) 1877-1885, 1882-04-15
CANAL REPORT.

The subjoined is the report of g. p.
Low, civil engineer, to the War Depart
ment on the contemplated canal from Hen
nepin to the Mississippi river at Rock Is
land. The first survey was made for a
ship canal, but this was found unnecessary,
and the report was accordingly made on
the basis of commercial canal of about
the same capacity as the Illinois and
Michigan canal. The report is as fol-
lows:
1--WE were fortunate in making a careful
measurement of the amount of water flow
ing in the Rock River at a time, October
II, 1870, when, according to the residents
of that city, the river was at its lowest
known stage. The amount of water at
that date was found to be 2, 446 cubic feet
per sound, which, under the present avail
able head of seven feet, gives, theoretical
ly, /, 943 horse power"
'SThe facts in relation to the large canal
having been brought to your notice, you
verbally directed me to report and estimate
upon canal of smaller section. l have,
therefore, proposed canal section 60 feet
wide at the water line, and 6 feet deep,
and having slopes of 2 to 1, with locks $50
feet in length and 81 feet in width. These
dimensions correspond to those adopted
by J. o. Hudnutt, civil engineer, in his es-
Inmates for a canal over nearly the same
route, based upon surveys made in the
| summer Of 1867
'"The amount of water required for this
| canal is estimated as follows: For evapo-
ration and leakage, 1 .33 cubic feet per
mile per second, of 100 cubic feet per sec
ond for canal and feeder; for two hundred
I l. l.
| feet per second, making a total demand
from Rock River, at Dixon, of III cable
| feet per second. With feeder so feet
| wide and feet deep. with slopes of 2 to
| 1. the sectional area will be 228 square
feet, and the velocity required to the above
quantity 0.95 feet per second. To obtain
this velocity through the above section, it
will be necessary to give to the bottom of
the feeder an inclination of 0.16 feet to
the mile, or feet fall from Dixon to the
junction with the main line"
THE eastern division. from the Illinois
river to the feeder, is estimated to cost
ST ,467, 202. IA The western division from
the feeder to the Mississippi, 81 ,429, 70S.-
So The feeder, 81 ,002 611.70, making
the total for the whole work $3.50, 722. :
g. or SO, $40, 970.63 less than for the lar
ger canal. The surveys were made wholly
Tor Jne purpose OF locating canal IOO
feet wide, and the narrower section would
probably admit of following the bluffs
more closely and thus effect large saving
of earth work.
The locks proposed flor this work will
admit boats of a capacity Of $50 tons At
three locksful to boat, 1890 tons
could be passed daily"
Freight could be brought in lows from
points on the Upper Mississippi to the
canal and then by horsepower through
this canal to the Illinois river, and through
the Illinois and Michigan canal to Chicago
without breaking bulk / have not con-
sidered it any part of my duties to report
upon the commercial advantages of this
project, nor have at hand sufficient data
for the purpose. have endeavored to
make the estimate sufficiently high, and
am of the opinion that the amount stated
above would fully cover the cost of con-
struction. The amount of earth work
would probably be somewhat reduced up
on final location. No estimate has been
made for land damages, but it is presumed
that the counties and cities Immediately
benefited by the work would relieve the
Government from any expenditure under
that head"
Very respectfully, your obedient ser
want
GoRHAM P. Low, JR.,
Civil Engineer, Assistant.