154 ELEMENTS OF GENERAL SCIENCE 



travel is like inland water travel, only over greater distances, 

 usually with larger vessels, and between different peoples 

 instead of between different parts of the same people, a study 

 of inland waterways will give an insight into both. In bulk 

 of business inland waterways are very important (fig. 78). 

 The traffic through Sault Sainte Marie Canal, connecting 

 Lakes Superior and Huron, is about four tunes as great as 

 that through Suez Canal, even though the Sault Canal is 

 closed by ice about five months of the year. A yet greater 

 amount of traffic passes through the Detroit River, and this 

 stream is one of the busiest waterways in the world. 



168. Water transportation on the Great Lakes. Much of 

 the commerce of Chicago, 1 the greatest railroad center in the 

 country, is carried by water, owing to certain advantages of 

 water transportation. In the first place, it is often cheaper, 

 since it costs a good deal to build railways. There is less 

 expense for repairs of boats, harbors, and docks than of 

 roadbed, track, and rolling stock. 



Water transportation is usually slower than transportation 

 by rail. In the shipment of such slow-moving water freight 

 as coal or lumber it is necessary to start the freight so as 

 to have plenty of time. Heavy and bulky articles, such as 

 coal, iron ore, stone, lumber, and grain, are commonly trans- 

 ported by lake or river route where this is possible. One of 

 the most important phases of the use of the Lakes to-day is 

 the transportation of iron from the mines near the west end 

 of Lake Superior and near Green Bay to the iron and steel 

 plants on the shores of Lakes Michigan and Erie. The great 

 furnaces of South Chicago, Indiana Harbor, and Gary at the 

 south end of Lake Michigan are supplied by lines of steamers 

 which run directly from the ore docks on Lake Superior and 



1 In this chapter and those that follow, conditions about the Great Lakes 

 are frequently cited as illustrations. Those of other regions where the records 

 have been kept for a considerable period will serve equally well, and such 

 records should be secured as a means of demonstrating the local importance 

 of the facts under discussion. 



