The Use of Ships 
1983 
and the limestone reefs of the Detroit River have been blasted out to 
form a deep ship channel. Hence the lakes can be navigated by large 
ships from Duluth at the head of Lake Superior, or from Chicago near 
the head of Lake Michigan, to the foot of Lake Ontario. From Buf- 
falo the Erie Barge Canal makes connections with the Hudson River, 
while from the foot of Lake Ontario the St. Lawrence River connects 
with the Atlantic Ocean (Fig. 137). 
The value of the Great Lakes as a waterway is increased by the fact 
that from their eastern end commerce finds an easy outlet through 
the Mohawk-Hudson valley to New York City. As far as the Hudson 
the valley contains the Erie Barge Canal, four tracks of the New York 
Central Railroad, two tracks of the West Shore Railroad, and two high- 
ways. These easy lines of communication have made the Great Lakes 
an important contributor to the growth of New York City. 
Why more freight moves east than west on the Great Lakes. The 
movement of freight on the Great Lakes is largely from west to east. 
Not far west of Lake Superior, in Minnesota, Manitoba, and the Da- 
kotas, lie some of the world’s greatest wheat fields (Fig. 28). Around 
Lake Michigan are similar fields where corn as well as wheat is grown 
(Fig. 81). The grain raised on these western farms is carried eastward 
to be consumed in the Atlantic states or Europe. It forms a large part 
of the freight on the Great Lakes. 
Iron ore also goes eastward. The richest and most extensive iron 
mines lie near Lake Superior, while vast beds of coal are found not 
far from Lake Erie in Pennsylvania and Ohio (Figs. 88, 98). Since 
about two tons of coal are needed to smelt a ton of iron ore, it is cheaper 
to carry the ore eastward to the coal than the coal westward to the ore. 
Moreover, the chief markets for the smelted pig iron and for the steel 
made from it are the Atlantic states and Europe, which is another rea- 
son for carrying the ore eastward. 
In order that the ships which bring grain and ore from the west may 
have cargoes on their return voyages, the westward freight rate has 
been reduced until it is only about half as much as the eastward. This 
makes it worth while to carry millions of tons of soft coal to the Lake 
Superior region for use in smelting iron near the mines, and of hard 
coal from the eastern anthracite fields for house fuel through the Mid- 
dle West. Yet in spite of the reduced rates, many of the westbound 
vessels go empty to the ports of the upper lakes where they get their 
grain and iron ore. 
Why the cost of transportation on the Great Lakes is low. In order 
to get as much ore as possible into each vessel, special steamers are