5 



of years since Indiana, our home, was raised from the bottom 

 of the sea, and became permanently dry land. Geologists 

 arrive at these figures by mathematical calculation. By a care- 

 ful observation of the surface of continental lands, and meas- 

 urements of depths of erosion, it is found that at least six 

 thousand feet in depth of surface has been eroded, gathered by 

 rivulets, and transported by the larger streams to the sea. 

 They have also determined the carrying capacity of streams, 

 by measuring the amount of sediment carried at different sea- 

 sons of the year, and at various stages of high and low water, 

 and find that it requires about five thousand years to remove 

 an average thickness of one foot from the continental surface. 

 Then, if five thousand years are required to remove one foot, 

 to remove six thousand feet would require thirty millions of 

 years. This estimate is considered by Geologists to be an 

 under, rather than an over estimate of time. 



We now come to the last great epoch which impressed its 

 individuality upon the surface of Indiana, and gave to it, its 

 present facial contour, "The Great Ice Age." During the 

 earlier part of the quaternary period the crust of the earth was 

 subject to varied and wide-spread oscillations, elevations and 

 depressions. Elevations were most marked in higher latitudes 

 And on our own continent most marked through the north 

 central portion, comprising Labrador, the Canadas, and the 

 great lake region. These oscillations being attended by great 

 changes in climate. The elevated regions being subject to 

 great frigidity. The territories mentioned lying immediately 

 north of us, sustained an elevation of from two to three thous- 

 and feet, and from continued snow fall during a long period of 

 time, became covered with ice to a depth of from five to ten 

 thousand feet, known as the great continental ice sheet, which 

 extended south near Cincinnati, a few miles below the Ohio 

 river. From this point the lower border of the ice sheet took 

 a northeasterly and northwesterly course. Northeasterly to 

 the coast line near Long Island, northwesterly into the British 

 possessions, where it has not been accurately traced. The 

 cause of the great glacial, or ice epoch, is not fully under- 



