INTKODUCTION. 5 



line of Indiana and Ohio, while those on the west have an irregular 

 boundary. From the head of Lake Michigan southward nearly to latitude 

 41° the west boundary is at the State line of Indiana and Illinois, but 

 south from this line it extends west into Illinois about 25 miles, being very 

 near longitude 88°. 



The Third Principal Meridian leads north from the mouth of the Ohio 

 River to the Wisconsin line. It is about 8 miles west of longitude 89°. 

 The base line is a direct continuation of the base line of the second merid- 

 ian survey in southern Indiana. It enters Illinois from Indiana just north 

 of the city of Mount Carmel and touches the south part of Centralia and 

 Belleville, coming to the Mississippi River immediately below St. Louis. 

 There are 17 townships south of the base line and 46 north of it. From 

 the north line of the State south to the Illinois River at Peru the ranges lie 

 entirely east of the Third Principal Meridian, but south from that stream 

 the ranges are numbered both to the east and to the west. To the east they 

 extend to the western limits of the survey based on the Second Principal 

 Meridian; to the west they extend to the Illinois River above the mouth of 

 that stream and to the Mississippi River south from the mouth of the 

 Illinois. 



The Fourth Principal Meridian leads from the Illinois. River at Beards- 

 town north to the Mississippi River about 8 miles above Rock Island, and is 

 continued in western Jo Daviess County. The base line leads directly 

 west from Beardstown to the Mississippi River, 6 miles above Quincy, and 

 is situated about 2 miles north of the fortieth parallel of latitude. The 

 townships south of the base line reach the number 14, while those north 

 reach 29. The ranges are numbered both to the east and to the west of the 

 principal meridian, north from Beardstown; south from that city they are 

 numbered only to the west. 



In Iowa and Missouri, together with several other States west of the 

 Mississippi, the land surveys are governed by the Fifth Principal Meridian, 

 which leads from the mouth of the Arkansas River north through eastern 

 Arkansas, eastern Missouri, and eastern Iowa. The base line crosses cen- 

 tral Arkansas, passing just south of the city of Little Rock. From this 

 base line the townships are numbered to the south as far as the line of 

 Arkansas and Louisiana. They are numbered to the north as far as the 

 international boundary in western Minnesota' and north Dakota. Eastern 



