The Ottawa free trader. [volume] (Ottawa, Ill.) 1843-1916, 1844-06-07

{ this place that it may be understood when
the proposed modification of the original
or thorough cut plan is discussed, why
? more extensive examinations were not
made in the first instance in reference to
) a supply Of water for the canal, from the
t various sources TO which ii is now propo-
/; sed to resort for that supply, in the mod-
! fled or more elevated summit level which
, II is proposed to substitute for that origin
: ally contemplated. The law i, will be
! seen was absolute, it admitted of no dis
erection in this particular, either on the
part of the commissioners or the enei-
neer; the lake, in any plan which might
be adopted for the canal, was to constitute
feeder.
Subsequently (n 1887 when the diff
cult character of the summit cut was fully
) developed, the question was discussed in
the legislature whether it might not be
found eXpedient to change the mode of
supplying the canal with water, and in
stead of relying upon lake Michigan for
from other "sources within the legitimate
authority Of the state of Illinois, could
not be rcsorted to. and BY this means OBJ
vIalc the grea, expense of the thorough
cut at the summit; the result of this dis
cuSsion was a law authorizing the en-
ployment of "skillul engineer to as
certain the facts aud make report of the
same. Under this law Mr.. Benjamin
Wright was called upon to investigate The
subject, and in his report to the commits
sioners Of the canal he states, IL have no
doubt upon my mind that the present plan
Of cutting down the summit so as to draw
feeding water from Lake Michigan. ought
To he continued IN preference to any other
which | can suggest" These views APP
pear to have been acquiesced in by the
legislature, for the question did not again
arise until all means for prosecuting the
work were exhausted, and it became nee
essay TO devise some plan for completing
the work upon less costly scale this
necessity gave rise To the Investigations
which resulted in the discovery by the
present engineer, that the plan could he
modified without serious delriment to the
work, and that an ample supply of water
could be dawn from other sources than
that Of Lake Michigan.
Before establishing the elevation to be
given to the summit level of the canal
careful examinations had been made to as
certain the extent of the variation, or nuc-
tuallon, in the depth of water in lake
Michigan. AT tha, period four feet was
considered TO be the extreme difference Of
level between the surface of the water at
It's highest and at its lowest stage this
element therefore determined the proper
elevation of the summit cut: the termna-
ton Of this summit level is at Lock port,
30 miles from Chicago creek, with de-
cliylly Of 0.l0 of a foot per mile. For 10
miles Of this distance the cutting averages
8 feet, from four to six feet of which is
a stiff blue clay, while the residue or sub
stratum is cemented clay; an exceedingly
difficult snd expensive material to exca-
vate. Flom the 10Th mile (Saxganaskl
swamp to the 81 mile, the cutting is in
Magnetism limestone, varying from II to
8 feet in depth. This limestone occurs
in strata of from to inches in thickness
It is very compact, and filed with organic
remains. 1t is occasionally lraverscd by
veins of vertical fssuIes of very pure clay,
from 2 inches to several feet in thickness.
Coble stone are found scattered through
the clay. In some instances the seam is
covered with layer of the rock, being
apparently deposit subsequent to that of
the clay. Holes too are found, which ap-
pear to have been worn out by the action
of the wafer: these holes are also filled
with clay and coble stone in every in.
stance.
Mr.. Gooding stated that he had disco.
vered but single instance Of cavernous
formation this was a, the bottom of the
cut, and extended deep into the earth.
After entering the valley Of the Des Pai-
mes, at Summit, the canal pursues the val,
ley of that stream uninterruptedly, and
without any essential deviation from a
tolerably direc, course until it reaches the
valley Of the Du Page river a, the 42d
mile; at that point i, changes its direction
from southwest to south, and pursues that
course nearly six miles, to turn the high
ground or spur which proiudes itself from
the north To the mouth of the Kankakce
river (the main southeastern branch Of the
lllnols); this spur, or ridge, forms what
is called the Kankakee Bluff, and ii also
forms one OF the most exposed and expon.
sive parts of. the canal between Lockport
and La Salln Tho nea pl,irs r;,ar