1889. | NEW YORK ACADEMY OF SCIENCES. 167 
spring which will make each wheel bear its fair proportion of 
weight, should it pass over any ordinary inequality in the rails. 
The ship-railway is to have practically no curves. By means 
of great deflecting-tables the direction of the ship-car whenever 
necessary is to be turned. The lay of the ground at Tehuan- 
tepec is very happily suited for such a great railroad. The ship 
can be borne across the isthmus at the rate of about eight or ten 
miles an hour or more. Ships using this railway would not 
only travel across the isthmus much faster than they could by 
means of a canal, but they would in various respects be safer on 
the railroad car. A vessel passing through a canal has to move 
very slowly; it is always in danger of being injured by going a 
little too close to the side of the canal, and may even at times 
ground under very unpleasant circumstances. 
There are various reasons why a ship-railway located at 
Tehuantepec will be of great value to the commerce of the 
United States. It will be within a few hundred miles of the 
city of Mexico. It can easily be united to the railroad system 
of North America. Its commercial relations with the United 
States and Mexico will necessarily be peculiarly intimate. Eads 
planned to make a very fine harbor for Tehuantepec, which 
would become an entrepdt for a vast commerce with Mexico, 
and where vessels could readily be supplied with an abundance 
of coal from the United States. 
To appreciate even faintly the value of a ship-railway at this 
point, one needs to glance at a map of the American continent 
and then to extend his view to the map of the world. The 
American continent is the greatest in length of any continent 
on the globe. A vessel going from New York to San Francisco 
cannot sail around the northern part of America, through the 
icy regions of the Arctic Ocean; while to go around its cold and 
stormy southern extremity, at Cape Horn, necessitates the sail- 
ing of 14,200 nautical miles,—a nautical mile being about one- 
sixth greater in length than isa statute mile. A ship-railway 
at Tehuantepec would shorten this distance by 9,800 miles, 
making the voyage but 4,400 miles. 
One might here pause and consider how inestimably important 
to nations is commerce—how it affects the comfort, the wealth, 
the intellectual tone, and the manners ofa people. It is ameans 
of binding together in happy relations widely separated countries. 
Many an humble workman living in the city of New York has 
~upon his breakfast-table tea which has been transported nine- 
teen or more thousand miles from China, sugar which was ob- 
tained from sugar-cane which grew in Cuba or in India, and 
fruits that were raised in climates suited to their growth. 
Perhaps the bread which he eats was made of wheat raised on 
