MCE COUNTY. 



BridgewaUr kame.] 



This kame, the course of which has been described, consists entirely of 

 gray gravel. It generally has not a sudden depression immediately along- 

 side, in the average level of the country, but the kame rises abruptly from* 

 the general flat, the angle being from 25 to 35 from the horizon. Yet, 

 although there is not a sudden depression where it lies, there is perceptible, 

 in some cases, a broad, basin-shaped valley through the lowest parts of 

 which it passes. This broad, smooth valley is from a hundred to a hundred 

 and twenty rods in width. Such can be seen in sec. 21, Bridgewater. The 

 hight of the ridge is usually from thirty to forty feet, with a smooth exterior; 

 but near the school-house, in the west part of sec. 33, Bridgewater, its hight 

 is from seventy-five to eighty feet, and in other places it has an average 

 hight of fifty feet. The accompanying sketch-map of its course, fig. 52, 

 was prepared with the assistance of Mr. W. H. Emery. 



Conclusions respecting the Bridgewater kame. Some important and neces- 

 sary conclusions result from the existence and nature of this kame. 



1. As it contains only gray gravel it must have been derived from the 

 gray, or northwestern till sheet. 



2. Its composition being gravel, water-worn, it must have been de- 

 posited by water. 



3. As it rises and falls, both on its upper and its lower surface, accord- 

 ing to the surface on which it lies, it cannot have been caused by beach- 

 action, and no other natural agent can be appealed to than a river in rapid 

 flow. 



4. The supply of the material of which it consists must have been 

 rapid and long-continued; hence the glacier ice must have been present. 



5. As a line of rolling morainic accumulations, the outer morainic belt 

 of the county, here occupies in general the valley of the Cannon river from 

 Faribault to sec. 33, Bridgewater, the kame must have been accumulated 

 during that prolonged stationary stage of the ice. 



6. As the ice would at that time have covered and enclosed the Cannon 

 valley above Bridgewater, and also the Minnesota valley, the water con- 

 cerned in its formation must have been that of the Straight river only. 

 Again, 



7. As the first outflow of the Minnesota through the Cannon valley 

 was at an elevation of about 1075 feet, forming at Northfield rather a broad, 



