1S2 Dr. BiGSBY on the Geography and Geology of Lake Huron. 



Having* completed my geographical observations on the Manitoulines, I shall 

 now proceed to describe the three principal divisions of Lake Huron. 



The north-west arm of Lake Huron, which communicates with Lake Su- 

 perior, is of an oblong shape, the two longer sides at their western extremities 

 converging towards the north. It contains about 400 square miles, and is 

 crowded with islands of all magnitudes. The principal of these is St. Joseph. 

 It is 65 miles in circumference; and, together with the large Sugar Island, is 

 wedged into the end of the channel from Lake Superior, scarcely allowing at 

 the narrowest points the breadth of a mile to the sum of the three outlets from 

 Lake George. 



St. Joseph is somewhat triangular in its form, its north and east sides meet- 

 ing almost at right angles. 



Although an undulating ridge called the Highlands of St. Joseph, about 

 500 feet high, is found throughout the island at the distance of a few miles 

 from the lake, yet the surface is not so broken as that of the Manitoulines ; and 

 the whole is better wooded. It has few or no precipices, but it is singularly 

 loaded with the debris of foreign rocks. Its southern point, a picturesque 

 cleared mound, once the site of a military post called Fort St. Joseph, and 

 lately occupied by the British garrison at Collier's Harbour for pasturage, is 

 only six miles from Drummond. The north-west point of the island is 26 

 miles from this mound, in long. 84° and lat. 46° 18' ; and the eastern angle 

 lies about 18 miles north -north-east of it by the ship's course. 



The waters on the north, west, and south-west of St. Joseph have received 

 distinct appellations. That on the south, bounded also by Drummond, is a 

 large irregularly shaped archipelago, containing sixty-one islands and many 

 shoals. 



The part of Lake Huron included between the north-east shore of St. Jo- 

 seph and the contiguous main, is called the Channel of Pelletau, from the 

 name of a solitary Canadian residing on an isle at its east end. Except towards 

 the western extremity, this channel is almost a clear sheet of water, from 10 to 

 12 miles long, 6 miles broad at the east end, and about a mile and a half at 

 the west. On the two sides of this channel the aspect of the country is very 

 different. On the south, the verdant acclivities of St. Joseph are trending to 

 the north-west in two large bays. On the north are the black and denuded 

 fastnesses of the main land; an assemblage of greenstone mounds, swamps, 

 and ponds; with the margin of the lake fringed with reefs and rocky islets. 



Near the west end, Pelletau's Channel widens into an expanse of 25 square 

 miles, and becomes full of islands, three of which are much larger than the 

 rest; and of these the largest is high, compact, and woody, and nearly blocks 



