: 377 
TABLE OF APPROXIMATE AVERAGE VELOCITIES, ILLINOIS RIVER 
This table is based on float records of J. L. Van Ornum, as published in 
Water Supply Paper No. 194, U. 8S. Geological Survey, 1907, pp. 17-18. 
(The gage at Peoria averaged about eighteen feet during the tests. The 
figures for nine feet are one half the 18-foot figures, various measurements by 
the U. 8S. Geological Survey and others showing about 50 per cent. decrease in 
velocity between approximately these gages at Peoria and corresponding gages 
at other stations.) 
e Gage, 18 ft., Peoria Gage, 9 ft., Peoria 
o 
Reach 5 
Ft. per min.) Mi. per hour| Ft. per min.| Mi. per hour 
Morris to Utica......... 33.9 229.47 2.60 114.73 | 1.30 
Utica to Grafton........ 229.6 115.43 1.31 57.61 0.65 
Utica to Hennepin...... 21.6 dismetc 1.56 68.86 0.78 
Hennepin to Henry..... 12.0 67.33 0.76 33.66 0.38 
Henry to Chillicothe....| 15.5 103.98 1.18 51.99 0.59 
Chillicothe to foot Main 
St COLia) teeters test 17.7 51.94 0.59 25.97 0.29 
Foot Main St., Peoria, to 
POKIMs age dere site eae et “ 9.8 191.64 2.17 95.82 1.08 
Pekin to Banner*....... 14.3) 414.40 1.30 57.20 0.65 
Banner to Liverpool....| 10.7 105.01 1.19 52.50 0.59 
Liverpool to Havana....| 8.0 66.00 0.75 33.00 0.37 
Havana to Beardstown..| 31.5 129.13 * 1.46 64.56 0.73 
Beardstown to Lagrange 
Ghat aqoesenenooomon 11.0 152.04 1.72 76.02 0.86 — 
Lagrange to Florence...| 21.9 146.92 1.66 73.47 0.83 
Florence to Kampsville 
(EF erlbsaet ome Peo Ge eee 24.2 183.85 2.08 91.92 1.04 
Kampsville dam to Graf- 
OTA Witte, datecaisyaia ate tere pe et 31.4 186.91 2.12 93.45 1.06 
Differences in velocity within the 18 miles between Chillicothe and 
Peoria are indirectly shown in the next table in figures for elevation of 
water surface at the low gage of 1901. In more than thirteen out of 
the eighteen miles the decline was too small to be measured; for one- 
half mile there was an average slope of over two inches; and in the 
lower four and a half miles a slope of about three fourths of an inch 
per mile. 
Widths between banks in this section of the river at the low water 
of 1901 ranged from 439 feet just below Chillicothe to more than a mile 
in the widest parts of the expanded portion known as Peoria Lake, 
which occupies more than seventeen of the eighteen and a half miles. 
If we figure the normal area of the river proper per mile throughout the 
reach at the 1901 low water at a mean (80.0 acres per'mile) between the 
* About 2 miles above Copperas Creek dam, 
