Daily Davenport Democrat. [volume] (Davenport, Iowa) 1864-1874, 1867-02-22
THE SURVEY OF the UPPER
RAPIDS.
Official gscpc~s Of General >. IS.
w Hon.


f,ofn L. Z sife to D,vcapert. distance Of
~ 2G -, O., measured On the Iowa shore,
with total iall Of alag ieef. Tho mean
width cf ,he Mississippi: in this distance IL
abou. 1900 feet. varying from 1900 feet
(M Port Byron) 10 3,eG0 feet, tbelow Camp
bells islaad.) The area Of cross sec ION
varies from G.s25 square feet ION Moline
cham The greatest velocity Is on the
Ioiinc "chsin," being G.ojf5 feet per sec
ond, or shout three and hall miles per
hour a, low water. The least velocity 10
found opposite Hampton. being not greater
than one and h ,li miles per hour
The great difference in photographic fea.
lures be,7cen the Rock Island and the
pys MON, rapids must lind its explanation
ul I'LL geological structure OF the country.
~ the nes MONIES rapids the river runs
over On inclined stratum 81 a single rock
formation, the cherry limestone Of the keo-
luS series, the dip e which is equal to the
prcscLt iucline,ion Of the water snr'aee.--
N The Rock Island rapids the e@log Al
conditions are entirely different. Here vs."
iird at the bead 81 lbc rapids, ear lie
Gia,r. tnacurslEn mrstune Of upper SIS
hlAan are, Nnga,e greup,l about fifty
ser thHch, dipping "a the sou'hwnri more
sstsI.t ihau HE surface of the water, It's
a layer. disap caring below water near
Hampton Succeeding THIS. in regular se-
qnencc, We find below Hampton, lmcssoncs
~ the Dcvoniau hg,, commonly referred TO
as tie Hampton group. the successive ledg-
es of which crop out on both river banks
aud occasionally in the river bed, forming
''r,e's" OF 'cbains.'
The consequence OF This difference IN
geological structure are At once apparent IN
"a COMPARISON Of the ROLES of the two rap>
ids. While in the Dcs Moincs rapids we
hnd a uniform depth and width throughout
their entire length, varying only ia depth
and width Of comparatively Insignificant iis
surcs or channels, We have in the Rock lS>
land rapids true reefs" aud "chnIns' Oh
s,ructing nav CATION for q short distance
each aud separated by deep intervals or
''p1ols" from six 10 thlsty feet in depth
OF the fourteen miles between the head and
foot pf the rapid, nearly eleven miles afford
good vsation IN the lowest stages, the OBJ
strucied PORTIONS coveringa distance OF only
n litlle more than three miles.
Al the Rock Island rapids the total des>
cent is about the sAmc Is at the Des MONIES
rapids, bn, in the latter case 1t i. mostly
foun! IN tho lower seven miles, v Mist in the
former it Is nearly equally distributed over
their entire fourteen miles.
Tine average length Of time when the wa
Ter is less than four feet ON Moline, the
shoalcst on the "chsins, is shout ninety
days; more than four feet about one HIM
drc'i and cigh days. or two-lhirds of the
average boating season.
From these oii cumstances, and the rea>
sons set '"r'h in the report Of my assistant
Brcv. Lieut.. Col. r. Y. fIaints, embodied
herein, have the honor to recommend that
tho navi CATION of these rapids be improved
by cxcavating he natural channel, So rs to
rave width OF 900 foot. and nayigable
depth II ipnr feet Mt extreme low water, the
plane u reference being tho 10. water &
lSGi
The disps,ity Of coat between this plan
aud that of a canal leaves no doubt l.. my
mind as 10 VIII ch should he aieptel, nos
vita landing the fact that the slackwater 4
the canal would be n great advantage IN :
self to the boats navi eating it.
|, ~ believed that the plan recommend
ed eau bc executed at these rapids w,.hout
any extraordinary diff culty, and rs the
r.vcr does not avcrag over two thousand
five hundred feet ia width, tho channel
w '''o' ~ =" ' ~,
' 80 '
r4a,',, r., ,.. "'a ~, ~ z,
-" -
NH s. $500, n..,,' ,,a.,a ~, rs
800 f'er.o p' ~ 80.
- 'm " ",'1"s '"o "e"'
'''"' .'s ~ ""' ue see" '"s' 'ne PROPOSED
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pau S'',''i '"e '''n'e ''"p''Ne"e't d ''e
nv 'e"'o' '"''"cf "ui 'o'e'"'"' "ec1S
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IA "heiie"ee to Your orders Oh the
''h ~ ~ t'"ef. lS'.' "Tret'ng ne TO pro,
ftCi ID nHNenp'it. Iowa, Tor thr purpose oil
m'Ain '"'alel snrveY ana examination
~ hocN Island harla' ~ me Mississippi
iFrr, nni o' Your letter containing more
ne'a'.sd distinctions % the same date.
have thc nov !" submit the following r.
P'' WV the accompanying drawings:
'sl' he'A"s' iowa, on the oth OF oc'o-
"e'' is'"' "r''' ~ davenport IOWA. the
"'N' "A,' anu 'h'"e"'a'e'y commenced or
g"A'g NY r'"eS' ana !" orae' 'na' ,hc
"''N ""s"' oe P"s"e' '".asa WIN 'he
g'es'est ueNp'oh consistent win the 'm>
P"'""c' "' tue WORK ana ,nssmuen rs tue
'">o" wv WIN ""u.. "e "i s"o'. o"'s'"",
Pu' mo ''c lc'n All ice 'ofee 'hat cou'u
VIZ 70 an'a"'age.
Ihc hNdrosrspn'c party Was placed mn
der the inncd ate charge ~ Mr.. y. r. Ao-
bet. c'vh engineer. Their work included
all thst related to the topography OF the
bed ot the river and other information con =
corning the tow OF the water over the rap
Ids.
.afscr p,rty was placed under the
charge ot Mr. W. ID. Clark. civil engineer,
with view OF making an accurate surv,y
OF the valley on both aides Of the river,
showing Tie ncandcrings OF the shores,
ari gathering oil other information neces.
safy Tor the Investigation Of the several
pro- c's Tor me improvement Of the nav :
CATION on the upper rapids Lines OF levels