166 TRANSACTIONS OF THE [APR. 22 
far from perfect, and a railroad system would be an invaluable 
blessing to the Chinese Empire. But probably vast numbers of 
Chinese would listen with incredulity should they be told of 
railways which accomplish for commerce far more than canals,— 
indeed, of railroad cars in America upon which Chinese canal- 
boats could be borne with wondrous speed over immense 
distances. 
James B. Eads, one of the most distinguished engineers of his 
age, devised a railway over which the largest ships in the world 
are to be transported across the American isthmus at Tehuante- 
pec. ‘The railway is to have what may be called heavy rails of 
fine steel. ‘The number of rails may be four, or six, or even 
eight, according to the size of the ship to be transported. At 
each end of the ship-railway, vessels are to be conducted into a 
basin which will open into what may be called a dry-dock, such 
as is used in raising out of the water the largest ships. As a 
vessel is raised out of the water, it finds itself on a great car which 
was waiting at the bottom of the dry-dock to receive it—a great 
car on wheels and onarailroad. By mechanical contrivances 
based on very interesting scientific principles, the ship is laid in 
its cradle as gently, one may almost be permitted to say, as a 
mother lays her babe upon its little bed. The railway car is to 
have a large number—some hundreds—of wheels, and is to be so 
admirably constructed of steel that it will possess very great 
strength. The ship when on the car is, by what may well be 
called a masterpiece of ingenuity, to rest on supports which will 
so adjust themselves to it that the vessel will be practically as 
truly water-borne as though it rested on a lake, the weight of the 
vessel being equally distributed over the entire car, The car, 
which is to be several hundred feet long, can be lengthened or 
shortened according to the size of the vessel which it is to trans- 
port. The car-wheels are to be two feet in diameter, and are to 
be placed three feet apart on the six or more rails on which the 
ship car is torun. The question may be raised, ‘‘ Would not a 
loaded ship,—which would weigh far more heavily in its centre 
than at its bow or stern,—when placed on a car, be of such enor- 
mous weight that the ground would yield under the crushing pres- 
sure which the rails would be called upon to bear ?” Hads, when 
dealing with such a question, showed that a vessel upon the ship- - 
car would have its weight, by the agency of its cradle and the 
construction of the car, so equalized and distributed over a large 
surface that no one of the wheels of the car will have to bear a 
weight greater than five tons, although each of them would be 
capable of sustaining twenty tons. Over each wheel will be placed 
a steel spring capable of bearing twenty tons before closing,—a 
