The most remote body of water tributary to Niagara River is Lake Superior, 381 miles long and 161 miles broad with a circumference of 1150 miles. The Niagara of Lake Superior is the St. Mary's River, twenty-seven miles in length, its current very rapid, with water flowing over great masses of rock into Lake Huron. Lake Huron is 218 miles long and 20 miles wider than Lake Superior, but with a circumference of only 812 miles. Lake Michigan is 345 miles long and 84 broad and enters Lake Huron through Mackinaw Straits which are four miles in length, with a fall of four feet. In turn Lake Huron empties into the St. Clair and Detroit rivers which, with a total fall of eleven feet in fifty-one miles, forms the Niagara of Lake Erie. This sheet of water is 250 miles long and 60 miles broad at its widest part. The area drained by these lakes is as follows, including their own area: Lake Superior 85,000 sq. m. " Huron 74,000 " " Michigan 70,040 " " Erie 39,680 " -------- Total 268,720 " Considering this as a portion of the St. Lawrence drainage, we have the marvellous spectacle of a navigable waterway from the St. Louis River, Lake Superior, to Cape Gaspé at the mouth of the St. Lawrence, of twenty-one hundred miles in length, the Niagara River being paralleled to-day by the Welland Canal, and lesser canals affording a passageway around the rapids of the St. Mary's in the West and the St. Lawrence in the East. In a previous volume in the present series[1] it was seen that the improved rivers in the Ohio basin now offered a navigable pathway over four thousand miles in length; how insignificant is that prospect in view of this great transcontinental waterway two thousand miles in length but including the 268,000 square miles in the four great lakes alone! Well does George Waldo Browne in his beautiful volume on this subject, _The St. Lawrence River_, say: Treated in a more extended manner, according to the ideas of the early French geographers, and taking either the river and lake of Nipigon, on the north of Superior, or the river St. Louis, flowing from the south-west, it has a grand total length of over two thousand miles. With its tributaries it drains over four hundred thousand square miles of country, made up of fertile valleys and plateaux inhabited by a prosperous people, desolate barrens, deep forests, where the foot of man has not yet left its imprint.