For the purpose of conveying all these things, they have two vessels upon the Lakes Erie and Huron, and one on Lake Superior, of from fifty to seventy tons burden. This being, therefore, the depot for transports, the Montreal canoes, on their arrival, were forwarded over Lake Superior, with only five men in each; the others were sent to Michilimakinac for additional canoes, which were required to prosecute the trade, and then taking a lading there, or at St. Mary's, and follow the others. At length they all arrive at the Grande Portage which is one hundred and sixty leagues from St. Mary's, coastways, and situated on a pleasant bay on the North side of the lake, in latitude 48. North, and longitude 90. West from Greenwich, where the compass has not above five degrees East variation.
At the entrance of the bay is an island which screens the harbour from every wind except the South. The shallowness of the water, however, renders it necessary for the vessel to anchor near a mile from the shore, where there is not more than fourteen feet water. This lake justifies the name that has been given to it; the Falls of St. Mary, which is its Northern extremity, being in latitude 46. 31. North, and in longitude 84. West, where there is no variation of the compass whatever, while its Southern extremity, at the river St. Louis, is in latitude 46. 45. North, and longitude 92. 10. West: its greatest breadth is one hundred and twenty miles, and its circumference, including its various bays, is not less than one thousand two hundred miles. Along its North shore is the safest navigation, as it is a continued mountainous embankment of rock, from three hundred to one thousand five hundred feet in height. There are numerous coves and sandy bays to land, which are frequently sheltered by islands from the swell of the lake. This is particularly the case at the distance of one hundred miles to the Eastward of the Grande Portage, and is called the Pays Plat.
This seems to have been caused by some convulsion of nature, for many of the islands display a composition of lava, intermixed with round stones of the size of a pigeon's egg. The surrounding rock is generally hard, and of a dark blue-grey, though it frequently has the appearance of iron and copper. The South side of the lake, from Point Shagoimigo East, is almost a continual straight line of sandy beach, interspersed with rocky precipices of lime-stones, sometimes rising to a hundred feet in height, without a bay. The embankments from that point Westward are, in general, of strong clay, mixed with stones, which renders the navigation irksome and dangerous. On the same side, at the river Tonnagan, is found a quantity of virgin copper. The Americans, soon after they got possession of that country, sent an engineer thither; and I should not be surprised to hear of their employing people to work the mine. Indeed, it might be well worthy the attention of the British subjects to work the mines on the North coast, though they are not supposed to be so rich as those on the South.