8 



extended lapse of time between the two glacial movements, 

 and that while there was a moderation of climate sufficient to 

 drive the ice sheet beyond the lakes, that nothing approaching 

 a tropical climate prevailed. Let this be as it may, the fact 

 remains, that the two glaciated areas present vastly different 

 appearances as to age, and indicate the lapse of many thousands 

 of years between the two ice sheets. Glacial drift as deposited 

 by the melting ice, is markedly undulating, presenting kames, 

 ridges, sinks or kettle holes, presenting very much the appear- 

 ance of the surface of Portage Prairie, or the region lying 

 between South Bend and Cassopolis, with which localities you 

 are all familiar, the surface being rolling, sharp elevations 

 and depressions, with numerous lakes among the hills dotting 

 its surface. It is fair to presume that the general surface from 

 the foot of the terminal Moraine of the last ice movement to 

 the lower glacial boundary, when deposited by the melting ice, 

 presented the same general characteristics. But, to the con- 

 trary, this intervening surface presents a monotonous aspect. 

 It is almost a level plain, no hills, no knobs, no kettle holes, no 

 deep valleys, while flat, shallow streams are the rule. Charles 

 R Dryer, in writing upon the geography of Indiana, gives this 

 fitting description of the central third of Indiana. " North of 

 an irregular line extending in an irregular direction from Rich- 

 mond to Terre Haute, and south of the westward flowing por- 

 tion of the Wabash, from Fort Wayne to Attica the topography 

 is that of an almost featureless drift plain. The traveler may 

 ride upon the railway train for hours without seeing a greater 

 elevation than a hay stack or a pile of saw dust." 



The time which has elapsed since that surface was lain 

 down by the withdrawal of the first or great ice sheet, is meas- 

 ured by so many thousands of years of aerial and aqueous 

 erosion, that hills and ridges have been leveled to the surface, 

 and its lakes have been filled by sedimentation and vegetable 

 growth. This you will remember was during the Champlain 

 epoch, or period of depression, when the surface abounded in 

 shallow pools, swamps and lagoons. Drainage was slow and 

 interrupted, with a general inclination to a leveling of the sur- 



