1889. ] NEW YORK ACADEMY OF SCIENCES. 171 
the world. As in some part of the Mississippi valley almost any 
climate can be found, the most varied products are always being 
borne in a very economical manner on its waters. 
For a long time the Mississippi River was closed to large ves- 
sels, owing to a bar at its entrance. Captain Eads rendered his 
country an inestimable service by devising a method of making 
a permanent channel at the entrance of the Mississippi—a 
channel of sufficient size to admit the largest vessels used in 
commerce. Altnough thus, and in various ways, Eads had per- 
formed services of very great value already to his country, yet 
he further aspired to the practical opening, for the immense 
commerce borne on the waters of the Mississippi, by means of a 
ship railway at Tehuantepec, of a channel into the waters of 
the Pacific Ocean, which covers nearly two-fifths of the sur- 
face of the globe, and waters the shores of continents and islands 
where live six or seven hundred millions of people. By a map 
of the Gulf of Mexico it will be seen that Tehuantepec is oppo- 
site to the point where the Mississippi River enters the Gulf. A 
vessel, when it sails from San Francisco to the mouth of the 
Mississippi, and goes around Cape Horn, has to travel about 
16,112 statute miles,—a much greater distance than it would have 
to go if it went to Asia or to Australia. Should it be trans- 
ported across the isthmus at Panama, it would have to sail 5,418 
miles, while at Tehuantepec it would need to travel only 3,561 
miles,—a less distance by 1,857 miles. By this route it would 
save on every round trip a distance of 3,714 miles, as compared 
with Panama. When one reflects how large a commerce might 
be carried on between the mouth of the Mississippi River and the 
western coast of the United States, he may well feel that it is a 
matter of vast importance to our people that the place of transit 
across the isthmus should be at Tehuantepec rather than at 
Panama. It would be worth many millions of dollars yearly to 
the great coastwise trade of the United States to be enabled to 
cross the isthmus at the former point rather than the latter. 
Eads, in planning a ship-railway to cross at Tehuantepec, had 
in view considerations of a military as well as of a commercial 
nature. During the great civil war in the United States, he had 
given much thought to some important military needs of his 
country. ‘Three days after the flag had been fired upon at Fort 
Sumter, he had been summoned to Washington by a member of 
Mr. Lincoln’s Cabinet to advise the Government respecting the 
wisest manner of utilizing for military purposes the Mississippi 
and other rivers. The great engineer himself at once built with 
wonderful despatch eight river gunboats. Shortly after pre- 
senting these formidable vessels to his Government, he had six 
more constructed, four of them being built in part on plans 
