176 Dr. BiGSBY on the GeograpJiT/ and Geology of Lake Huron. 



and showing occasional traces of limestone and sandstone. The mountains 

 deUneated on some of the maps of this district are purely imaginary. Among 

 its forest trees are the oak (white and black), ash, walnut, elm, poplar, maple, 

 and various pines. The magnificent nation of Ottawas at L'Arbre Croche, 

 and the Indians on the river Saguina, have long raised excellent vegetables. 



The country on the south-east or Canadian shore, from the St. Clair to 

 Cabot's Head, is, on the south, low and damp, with extensive pineries ; but 

 northerly it becomes stony and rugged, and its rivers are rapid. It is little 

 known. 



The height of Lake Huron above the sea has not been ascertained with 

 accuracy, but may, without great error, be stated at 590 feet. The Commis- 

 sioners for constructing the western canal in the State of New York, esti- 

 mated Lake Erie to be .560 feet above tide-water in the River Hudson. — 

 Mr. Schoolcraft, who accompanied Governor Cass in 1820 to the supposed 

 copper mines in Lake Superior, gives 29 feet as the difference in elevation 

 between Lakes Huron and Erie, — which must be near the truth *. 



The shape of Lake Huron is so extremely irregular as only to be learnt 

 from the accompanying map. Tracing its main shores loosely with a compass, 

 and omitting the lesser curvatures, its circumference is found to amount to 

 nearly a thousand miles. 



The distinguishing feature of this lake is its intersection by the Manitou- 

 line chain of islands, which stretches E.S.E. from the promontory of the True 

 Detour, and in longitude 82° approaches within two miles of the northern 

 main land, the strait being nearly filled by an islet. The chain then suddenly 

 trends south-east to Cabot's Head. 



Of the three portions into which the lake is divided by the Manitouline 

 chain, the two northern are full of shoals and islands, and that to the north- 

 west is comparatively narrow. The southern division is by much the largest, 

 and is deep, broad, and of free navigation. 



Besides the Manitouline chain, and these three principal divisions of the 

 lake, the other points in the geography of Lake Huron demanding particular 

 notice are, the island of St. Joseph lately assigned to Great Britain, Michili- 

 niackinac and its vicinity and the Gulf of Saguina. 



I have twice visited (in the years 1819 and 1820) the islands of St. Joseph 

 and Michilimackinac ; and on my second visit passed three months in their 

 vicinity. In 1819 I descended the French river from Lake Nipissing to Lake 



* One-third of the distance is horizontal ; straight and tolerably unobstructed rivers occupy 

 the remainder. 



