342 



EARTH FEATURES AND THEIR MEANING 



St. Ignace, its profile upon the horizon is worthy of remark (Fig. 

 369). From a central crest broken by minor irregularities and 

 bounded on all sides by a cliff, the island profile slopes gently 

 away to a still lower cliff, below which is another terrace. 



ing Level 



FIG. 369. View of Mackinac Island from the direction of St. Ignace. The ir- 

 regular central portion is the only part of the island that was not submerged in 

 Lake Algonquin. The terrace at its base is the old shore line of Lake Algon- 

 quin, and the lower terrace the strand of Lake Nipissing (after a photograph by 

 Taylor). 



When we have reached the island and have climbed to the 

 summit, we there find the surface which is characteristic of erosion, 

 by running water, whereas at lower levels are found the forms- 

 carved or molded by the action of waves. This central " island/* 

 superimposed upon the larger island, is all that rose above Lake 

 Algonquin, the earliest of the glacial lakes in this northern dis- 

 trict ; and as we look out from the observatory upon the summit, 



it is easy to call up a picture of 

 the country when the lake stood 

 at the base of this highest cliff. 

 To the northward one sees the 

 " Sugar Loaf " rise out of a sea 

 of foliage, as it formerly did 

 from the waters of Lake Algon- 

 quin (Fig. 370). It is a huge 

 stack near the former island 

 shore. If we turn now to the 

 southward and direct our gaze 

 toward the Fort, we encounter 

 a veritable succession of beach ridges formed of shingle and ranged 

 like a series of waves within the cleared space of the " Short 

 Target Range " (Fig. 371). These ridges mark each a stage within 



FIG. 370. The "Sugar Loaf," a stack 

 near the shore of Lake Algonquin, as 

 it is seen from the observatory upon 

 Mackinac Island (after a photograph 

 by Taylor). 



