The Great Lakes by James Oliver Curwood

Picture a train of forty-ton freight cars loaded to capacity, the engine and caboose both in New York City, yet extending in an unbroken line entirely around the earth -- a train reaching along a parallel from New York to San Francisco, across the Pacific, the Chinese Empire, Turkestan, Persia, the Mediterranean, mid the Atlantic -- and you have an idea of what the ships of the Great Lakes carry during a single eight months' season of navigation. At least you have the part of an idea. For were such a train conceivable, it would not only completely engirdle the earth along the fortieth degree of north latitude, but there would still be something like two thousand miles of it left over. In it would be two million five hundred thousand cars, and it would carry one hundred million tons of freight! Were this train to pass you at a given point at the rate of twenty miles an hour, you would have to stand there forty days and forty nights to see the end of it.

Only by allowing the imagination to paint such a picture as this can one conceive to any degree at all the immensity of the freight traffic on our Inland Seas.