CHAPTER I. 



GEOGRAPHICAL POSITION AND SURFACE CONFIGURATION 

 OF THE LOWER PENINSULA. 



The Lower Peninsula of Michigan comprises an area of about 

 35,000 square miles. It is situated between 82° 25' and 86° 50' of 

 longitude, west from Greenwich, and 41° 44' and 45° 47' of northern 

 latitude. 



On the west it is bounded by Lake Michigan, on the north by 

 the Straits of Mackinac, on the east by Lake Huron, Lake St. 

 Clair and Lake Erie, besides the intermediate, river-like arms con- 

 necting the three lakes. 



The southern limits are formed by the State lines of Ohio and 

 Indiana. In a north and south direction, the greatest length of 

 the peninsula is two hundred and seventy-five miles. In an east 

 and west direction, the greatest width, coincident with a line drawn 

 from Port Huron to Grand Haven, is about 200 miles. 



Lake Michigan is 320 miles in length and 100 miles broad at 

 the widest part, its total area being 22,000 square miles. Lake 

 Huron is 260 miles long; 160 miles is the maximum of its breadth, 

 and 20,400 square miles its surface extent. Both lakes have about 

 an equal elevation above the ocean level, which is 578 feet. The ele- 

 vation of Lake Erie above the ocean is 565 feet. These immense 

 sweet-water basins, carved out in some places to a depth of over 

 900 feet, are evidently the result of eroding forces, acting on the 

 sedimentary strata which once were spread without interruption 

 across this entire lacustrine area, and these forces undoubtedly were 

 identical with those by which the heavy masses of rock debris, 

 known by the name of drift, were accumulated over a large zone 

 of the northern hemisphere in this and in other continents. The 

 longitudinal axes of Lake Michigan and of Lake Huron approxi- 

 mately have a north and south direction. Coi^ncideat. with them 

 I 



