168 



GEOLOGY OF LA SALLE COUNTY. 



reach an elevation of 640 to 650 feet. 



The north half of Meriden Township rang-es 

 between 730 and 850 feet. 



Here is a broad field for investigation. It is to be 

 reg-retted 'that while the State was eng-aged in a-hyp- 

 sottietrical survey in 1892, an appropriation sufficient 

 to do the work thoroughly was not made. It was at 

 best but a roug-h reconnoissance with the aneroid, and 

 leaves much to be desired. 



COAL PRODUCTION OF LA SALLE COUNTY. 



For the year 1894, 1,134,087 tons; 1895, 1,084,552 

 tons; 1896, 1,409,085 tons. 



In 1895 La Salle was sixth county in the State in 

 quantity produced; in 1896 it ranked fifth. Mine In- 

 spector's Report. 



The Peddicord Artesian Well Drift, etc., 269 feet; 

 shale, 65; limestone, 25; St. Peters, 290; calciferous, 

 617; white sandstone, 262; limestone, 52; shale, 115; 

 slate, 112; shale, 9; limestone, 29; sandstone, 298. 

 The water comes from this. Limestone, 46 feet. To- 

 tal, 2,189. It is 618 feet above sea and 40 feet above 

 Lake Michig-an. 



The calciferous beds, it is sug-g-ested in State Geo- 

 logical Report, Vol. VII., probably embrace the 

 Potsdcwi. We cannot assent to this. We think the 

 sandstone 298 feet thick, from which the water comes, 

 is the Potsdam. 



The Blood-sucker or Leach — Hirudo Sang-uisug-a 

 — is found in the Illinois river, especially about rotten 

 floodwood and about rocks, in warm weather attaching 

 itself to the stone a little below the surface of the 

 water. We have found a species of this g-enus at- 

 tached to a land turtle. The young are a hundred or 

 more in number, and are for a time covered or brooded 



