42 WALKS AND TALKS. 



above the lake. As we pass along the limestone wall which 

 bounds the island, we see the waves breaking against the bar- 

 rier. We notice the peculiar smooth concavities into which 

 they wore the exposed surface. These are marks character- 

 istic of wave action. Our eyes follow along the weathered 

 buttresses to the summit. From bottom to top are the same 

 records of warring waves. There was evidently a time when 

 the lake acted at the height of 150 feet precisely as it acts 

 to-day at the lake-level, before our eyes. We ascend to the 

 main plateau of the island. On this rises a striking monu- 

 ment-like remnant of a formation which once covered the 

 whole of this plateau to an altitude at least 134 feet greater. 

 This is " Sugar Loaf." But notice the fashion of its sides. 

 Here, too, are the same smooth conchoidal depressions as the 

 lake is still carving in the wall at the water's edge. The waves 

 have certainly been there. The time was when Lakes Huron 

 and Michigan stood at least 200 feet higher than at present. 

 Think of that condition of things. Picture the lakes filled 

 up till the water covered Sugar Loaf. At present, Lake Su- 

 perior stands twenty feet higher than Lakes Michigan and 

 Huron. These are sixteen feet higher than Lake Erie ; and 

 the descent thence to Lake Ontario is 323 feet. This is accord- 

 ing to Gannett. Now, we find lake-terraces up to three, four 

 and five hundred feet above the present levels of the lakes. 

 But let us assume the principal terrace south of Lake Erie 

 as representing the highest flood of the lakes. This 220 feet 

 above Lake Erie, 204 feet above Lakes Huron and Michigan, 

 and 180 feet higher than Lake Superior. We have perfectly 

 satisfactory proof that the water of the Great Lakes has stood 

 at least as high as this. Now let us cast our eyes over the 

 expanse. The sites of all the busy and populous lake cities 

 are submerged. The greater part of the peninsula of Ontario 

 is under water. The flood stretches westward of Detroit 

 twenty-seven miles. There, near Ypsilanti is the ancient beach 

 which marks the limit of the flood. Mackinac Island is sub- 

 merged to the pinnacle of Sugar Loaf. Passing around to 

 the head of Lake Michigan, we find the vast inland sea 



