374 ILLINOIS STATE ACADEMY OF SCIENCE 



due to party influence which brought about the authoriza- 

 tion of the project, encountered the most meager con- 

 sideration of the evident future of rail transportation, 

 the vahie of the water-way as a ''regulator" in its 1890 

 environment would have caused it to be held up for even 

 a longer period, if not prevented the expenditure of the 

 more than seven millions of dollars for its construction. 



The geography of the region between the Illinois and 

 Mississippi Bivers determined both the general and the 

 specific location of the waterway. The great bend of the 

 Illinois and the eastward bend of the Mississippi near 

 Eock Island invited connection by an artificial waterway. 

 The depression of Bureau Creek led westward from the 

 Illinois at a place where a lake afforded an eastern 

 terminal harbor. Green Eiver led westward from the 

 slope of the morainal divide to the navigable Eock River, 

 whose channel led directly to the Mississippi. The re- 

 lation of the upper Green River to the flat divide of 

 summit level offered the first suggestion of a to-be-im- 

 pounded w^ater supply from which the canal could be fed 

 both eastward and westward. Later surveys set forth 

 the feasibility of bringing southward along the flat crest 

 of the divide a canal feeder from the upper course of the 

 Rock Eiver, thus assuring a cheap and satisfactory sup- 

 ply of the water necessary for canal maintenance. The 

 character of the Mississippi between the mouth of the 

 Eock Eiver and the town of Comanche, Iowa, to the 

 northward introduced the problem of finding a suitable 

 western terminus, thus modifying the location of the 

 western half of the waterway. The intervening land 

 mass between the Illinois and the Mississippi did not 

 offer a serious problem in canal construction. The 

 height of the divide necessitated a rise of one hundred 

 ninety-nine feet above river level at low water, an ele- 

 vation accomplished by twenty-one ordinary locks. 



[In passing it is interesting to note that in 1894 lock 

 construction marked the beginning of the use of concrete 

 in canal building.] 



The highways of the region introduced a problem of 

 bridge construction and highway embankments; the 



