It will be assisting the reader, ere we proceed to detail the operations at the commencement of hostilities, to give a brief description, not only of the lakes and straits which constitute the water boundaries of Upper Canada, and of the towns and military posts distributed along them, as existing in the year 1812, but also of the territory of Michigan, which was surrendered, with Detroit, to Major-General Brock. The distances are given in British statute miles. The most remote piece of water on this frontier worthy of notice is Lake Superior, a body of fresh water unequalled by any upon the face of the globe. Lake Superior is of a triangular form; in length 381, in breadth 161, and in circumference about 1,150 miles. Among its islands is one nearly two-thirds as large as Jamaica. Out of Lake Superior a very rapid current flows, over immense masses of rock, along a channel of 27 miles in length, called St. Mary's River, into Lake Huron, at the head of which is the British island of St. Joseph, containing a small garrison. This isolated post is distant about 350 miles by water from Amherstburg, which contained the nearest British garrison. Lake Huron is in length, from west to east, 218 miles; in breadth, 180; and in circumference, through its numerous curvatures, 812 miles. Except the island of St. Joseph, and one or two trading establishments belonging to the north-west company, the shores of this lake were in a state of nature, or inhabited only by Indians. When the Americans were allowed to obtain the dominion of Lake Erie, which they did in 1813, it was determined at the close of the following year to create a naval force on Lake Huron in the ensuing season, (1815,) as possessing much greater security for the construction of vessels than Lake Erie, where the enemy could at any time destroy them, in the same manner as their vessels ought to have been previously destroyed by the British. Lake Michigan, which belongs wholly to the United States, is connected with Lake Huron at its western angle by a short and wide strait, in the centre of which is the island of Michilimakinack, belonging to the United States. This island is about 9 miles in circumference, and, like St. Joseph, its neighbour, it possessed a small fort and garrison. Lake Huron flows through the river St. Clair, which is in length about 60 miles, into Lake St. Clair, a small circular lake 30 miles in diameter. The beautiful river Thames, in Upper Canada, opens into Lake St. Clair, and it was along the banks of this river that Major-General Proctor retreated in 1813. From Lake St. Clair, the stream, through the Detroit, navigable for vessels not drawing more than fourteen feet water, pursues a course of nearly 40 miles into Lake Erie.