56 Dr J. J. Bigsby on the 



Thus the furious rapids, called the Falls of St Mary, on the river 

 of discharge so named, are sometimes left dry. Messrs Foster and 

 Whitney have seen the oscillation come from the centre of the lake 

 in a wave 20 feet high — curling over like an immense surge, crested 

 with foam, and breaking on the shore, diminishing as it approached it. 

 On this occasion (Aug. 1 845) it was the harbinger of a violent storm.* 



The amount of water leaving the lake is small : for its outlet is 

 often shallow, and the current weak. 



Tlie Climate is more arctic than temperate, although the lake is 

 but little to the north of Milan. It is much colder than Sikla in 

 Russian America, 10° further north; because the latter is screened 

 from polar winds. Winter begins in the middle of October by a 

 succession of gales and snow storms ; and from November till May 

 the ground is covered with close packed, granular snow ; but the 

 earth is not frozen deep, so that, in spring, before all the snow is 

 gone, the forest is in leaf. The annual range of the thermometer 

 is 125° F. the mean 42° 14' F.; the lower extreme — 31°, the higher 

 94° ; all these observations having been made by good observers, 

 with excellent instruments. August is the hottest month. 



On a mean of 12 years, the winds blow about equally from all 

 quarters ; from the NW. the most frequently — from the south the 

 least frequently. 



The scenery of Lake Superior is striking ; — its features are large 

 and open (of which an example was shewn in a Sketch on the East 

 Coast). The eye ranges over high lands and shoreless waters. 

 The scanty and dwarfed woods of the north coast, the rocks, isles, 

 and rivers full of cascades, have an impress of their own — not warm, 

 soft, and umbrageous, like those of Lake Erie ; but rugged, bare, 

 and chill — arctic. The scene is oceanic, — the waves are large and 

 high. Some of the plants, the Lathy rus maritimus and the Poly- 

 gonum maritimum, for instance, on the beaches, and many of the 

 insects disporting about, are those of the distant Atlantic. 



In winter, Lake Superior might be called the " Dead Sea ;" 

 every living thing is gone, save the shivering inhabitants of some 

 few white settlements. The Indian and the wild animals have re- 

 treated to the warm woods far away ; and the sun looks down, from 

 a bright blue sky, on the leaden waters, now narrowed by huge fields 

 of ice — a small dark speck on an almost illimitable expanse of snow. 



On the south shore, there are in the extreme east, high terraces 

 and treeless plains of blown sand for many miles inland and along 

 shore, succeeded by the high sandstone precipices, called the Pictured 

 Rocks, battered into fanciful shapes by the violence of the waves. 

 Then comes a low rocky coast for 200 miles or more, backed by 



* A violent gale of wind, concurring with a local rise of level., will some- 

 times throw large stones or logs of wood 150 to 200 yards inland, and 30 to 40 

 feet above the usual water margin- as in three instances seen by Prof. Agassiz 

 (L, Superior, pp. 05 and 106), and by Dr Bigsby. (Jour. Roy. Inst, xviii. 15.) 



