We now come to the site of the five largest fresh-water lakes in the world. Lake Superior extends, from west to east, 335 miles, with an extreme breadth of 175. Its waters flow through the Saint Mary's River by a rapid descent into Lake Huron, which is 240 miles long. This lake is divided by the Manitoulin islands into two portions, and is connected with Lake Michigan by a narrow channel without rapids, so that the two lakes together may be considered to form one sheet of water. On its southern extremity the waters of Lake Huron flow through another narrow channel, which expands during part of its course into Lake Saint Clair; and they then enter Lake Erie, which has a length of 265 miles, and a breadth of 80 miles. It is of much less depth than the other lakes, and its surface is therefore easily broken up into dangerous billows by strong winds. Passing onward towards the north-east, the current enters the Niagara River, about half-way down which it leaps along a rocky ledge of 100 feet in height, to a lower level, forming the celebrated Falls of Niagara, and then passes on in a rapid course into Lake Ontario. The fall between the two lakes is 333 feet. Lake Ontario is 180 miles long and 65 miles wide. Out of its north-eastern end falls the broad stream which here generally takes the name of the Saint Lawrence, and which proceeds onward, now widening into lake-like expanses full of islands, now compressed into a narrow channel, in a north-easterly direction. The true Saint Lawrence may indeed be considered as traversing the whole system of the great lakes of North America, and thus being little less than a thousand miles in direct length; indeed, including its windings, it is fully two thousand miles long. To the north-west of it exist countless numbers of small lakes united by a network of streams; while numerous large rivers, such as the Ottawa, the Saint Maurice, and the Saguenay, flow into it, and assist to swell its current. There are numerous other small lakes to the west of the Rocky Mountains, a large number of which exist in the Province of British Columbia, and are more or less connected with the Fraser and Columbia Rivers. Further to the south are other lakes, many of them of volcanic origin, some intensely salt, others formed of hot mud. Among these is the Great Salt Lake, in the State of Utah. To the south of the Saint Lawrence also is Lake Champlain, 105 miles long, though extremely narrow,--being only 10 miles in its widest part, narrowing in some places to half a mile. Near it is the beautiful Lake Saint George, with several other small lakes; and lastly, in Florida, there is a chain of small lakes, terminating in Lake Okechodee--a circular sheet of water about thirty miles in diameter. We must now proceed more particularly to examine the regions of which we have obtained the preceding cursory view, but, before we do so, we must glance at their human inhabitants.