"How can they be compared?" replied his uncle. "That was a long trench, hardly more than a scratch on the surface of the ground. This is broad and deep, though not long."
"Yes," said Mr. Towne, "but there is no new principle here. This canal is somewhat wider and deeper; its locks and gates are somewhat larger. Still it is only a canal."
"But we could not make such a hole in our day. We could not afford to hire men enough to dig it; it must have required many years to make this excavation."
"Oh; this canal was not made as large as this when it was first built. It has been enlarged since. But you know that we do not do all our digging now by hand. Steam shovels do the work for us. That gives us a great advantage over the day laborer with his pick and shovel."
"What strikes me as most noticeable," said Mr. Greenleaf, "is the number of vessels waiting on both sides of the lock. What causes such a crowd to-day, particularly?"
"This is no unusual number," replied Mr. Towne. "You do not realize what a traffic there is on the great lakes. It is stated that the tonnage passing through this canal is greater than that through any other strait on the face of the globe. This growth is very recent and very rapid."
"But what causes the traffic and where are all the vessels going?" asked the missionary.
"The great bulk of the freight," answered the younger man, "is grain from the Northwest, and iron, copper, coal, and lumber, now being obtained in vast quantities south of Lake Superior. So long as the steamboats can carry freight more cheaply than the steam cars, grain and ores will take this route. Sometime we shall have canals large enough for ocean steamers, which will connect the great lakes with the Atlantic Ocean. Then we can load our freight at Chicago or Duluth and not change it until it is unloaded at some English or European port."
The next day, as the steamboat was lying at the wharf at Detroit, conversation was turned to the great ferryboats plying across the river.
"I notice great changes in the steam ferries, since last I crossed the North River at New York," remarked Mr. Greenleaf.