268 Wisconsin Academy of Sciences, Arts^ and Letters. 



the rock forming the detrital material is so 'close that, were the 

 Swiss hill transplanted to certain localities in Eastern Wisconsin, 

 probably no geologist would ever detect the imposition, unless 

 fossils, of which I saw none, were found in it. 



16. In company with our genial vice consul [at Geneva, Dr. 

 Delavan, I had the pleasure of visiting the celebrated Jardin, in 

 the Chamouni region. A four hours walk up the Mer de Glace 

 and over the Glacier de Talefre brought us to an island of sub-trian- 

 gular outline, completely encompassed by a sheet of snow and ice ; 

 and around which clustered an amphitheater of mountain pinnacles. 

 It derives its name, " The Grarden," from the fact that, although 

 more than nine thousand feet above the sea, and surrounded on 

 all sides by perpetual snow and icp, a handsome flora of grasses 

 and bright, beautiful, little flowers bloom on its southward sloping 

 side. But, putting aside this interesting phenomenon, and re- 

 straining the sentiments, which the magnificent surroundings and 

 the grand views of Mount Blanc and the glaciers below inspire, I 

 can only, in this connection, remark upon the point of chief, geo- 

 logical interest to us, viz.: the likeness to our driftless area which 

 this glacier-girt island presents. Let me say, however, at the out- 

 set, that the Jardin is not a driftless area. It was formerly covered 

 by an ice sheet and contains erratics on its surface. But at present, 

 though the glacier originates much higher up the slope, it divides 

 and passes around the Jardin and again unites below it, leaving it, 

 so far as present action is concerned, a non-glaciated area, sur- 

 rounded on all sides by active glaciation. 



Its likeness to our driftless area, however, ceases here. It is 

 walled in, as is appropriate to a garden, by a steep sharp moraine, 

 thrust up by the ice in moving around it. On the border of our 

 driftless area, the glacial debris thins out very gradually and dis- 

 appears in an obscure margin. The Jardin differs also, in that it 

 appears to owe its immunity from present glacial action more to 

 its own prominence than to the effects of adjacent depressions. 

 The driftless area of Wisconsin does not lie, like it, on the sum- 

 mit of a protuberance, but on its lee side. The ice of the glacial 

 period surmounted the Archtean heights, south of Lake Superior, 

 in Wisconsin and Michigan, and descended the southern slope a 



