Statement of Elevations in Wisconsin. 259 



Rock River canal ; some are estimated by levels taken at the vari- 

 ous rapids along the rivers and adding for the distances between, 

 what is ascertained, in other cases, to be about the average descent 

 of rivers of similar character. These are marked by an interro- 

 gation. ? These elevations were taken with reference to the sur- 

 face of Lake Michigan as a zero, which is thirteen feet above 

 Lake Erie, and consequently five hundred and seventy eight feet 

 above the ocean.* In the following table, this number has been 

 added, so as to give the elevation above the ocean in each case. 



Feet. 



Rock river at its source near Lake Winnebago, . 894? 



" " at a point opposite La Belle Lake, . 835 



" " Jefferson or " the Forks,'' . . . 764 

 " " Lake Koshkonong, (an expansion of Rock 



river,) ...... 753 



" " at Beloit, (south line of the Territory.) 706 

 " " at its mouth, (191 feet descent from state 



line, Capt. Cram,) . . . . 515 



Pishtakaf river at head marsh, .... 825 



" " at junction of Pewaukee outlet, . 808 



" " at foot of rapids at Prairieville, . 789 



" at Elgin, (30 miles below Territorial 



line, William Gooding's report,) 693 



Pewaukee Lake, a source of Pishtaka, . . . 83 1 



Bark river near Pewaukee summit, . . . 904 



Pewaukee summit, (M. and R. R. Canal,) . . 894 



Nagowicka Lake, (an expansion of Bark river,) . 882 



Nemahbin Lake, " " 867 



Silver Lake, (in the town of Summit, Milwaukee Co.) 857 



Oconomewoc Lake, 860 



Labelle Lake, 851 



High ground between Labelle Lake and Rock river, 835 



" west of Pewaukee Lake, . . . 971 

 Surface of Milwaukee river four miles above the city at 



head of rapids, (37 feet above Lake Michigan,) . 615 



Hills surrounding Milwaukee, (50 to 110 feet,) . 688 



Lake Winnebago, ...... 738 ? 



* Higgins' Michigan Geological Report, 1838 — 9. 

 1 Or " Fox river of the Illinois." 



