Although Eads took care to protect his special innovations by patent, he was most willing to explain them with care to other engineers and to have others profit by his improvements; and several of the mechanical novelties of his bridge are now in the commonest use, and have been taken advantage of even in such famous structures as the Brooklyn Bridge.
During the building of the bridge Eads spent many months in enforced absence, but while in Europe he always had his labor in mind, and, as I have said, brought home from France one of his most useful appliances. During his absence he left absolutely trustworthy and efficient engineers in charge of the work, and before leaving home he provided for accidents that might occur. So much work was done in the winter that great barriers had to be built to keep it clear of floating ice. One curious detail connected with the bridge is that the Milwaukee, one of the double-turreted gunboats which Eads had built from his own plans, and which had been with Farragut at Mobile, was bought now from a wrecking company, and her iron hull used in making the caissons; so that her usefulness still continued in peace as in war.
It has been said of Eads that he grappled with great problems in engineering, and solved them as easily as a boy subtracts two from six. While this is true, it must not be forgotten that he had not the school-training of an engineer. Nothing is more untrue than the statement that he was, like de Lesseps, only a contractor. He was a very unusually brilliant engineer, and his ignorance of the higher mathematics served to show his brilliancy the more clearly. Some persons have said that his chief talent was in explaining abstruse reasonings simply; but an engineer has told me that he thought Eads's chief talent was his ability to arrive by some rough means at a certain conclusion to a given problem, which conclusion would in every instance be approximately the same that better trained mathematicians would reach by mathematics.
By the time the bridge was finished, indeed from the time (1868) when his first report for it made a decided stir in the scientific world, both at home and abroad, Eads was a very well-known engineer. In that same year a visit to Europe for his health's sake gave him the opportunity to interview a French steel company, through whom he met a famous bridge-builder, and was led to examine the piers of the bridge then being constructed at Vichy; and it was there that he found his new ideas for caissons. Going home, by way of England, he explained his plans to the engineers there, and was by them proposed as a member of the Royal Society. Even at home, in his own adopted State, he was not without recognition; for in 1872 the University of Missouri conferred upon him the honorary degree of LL.D. From the general of engineers he received a request for suggestions for improvements in guns; and from his work on the subject of Naval Defenses it is plain that his mind still found time to run on this favorite topic.
In 1874 the bridge was finished. After it had satisfactorily stood the severe tests put upon it, it was formally opened on the 4th of July. The celebrations of that day were the first public outburst of approval given to Eads's work. And to-day the strong and graceful bridge stands as his most beautiful and lasting monument. And as even the great tornado of 1896 was unable to do the piers any serious damage, they are likely to last indefinitely, and thus make the bridge "endure," as its builder said, "as long as it is useful to man."
To Saint Louis it has been so useful that while on the one hand the growth of the city was the cause of its being built, on the other it has been one great cause of the continued growth and prosperity of the city. But it had even broader results than that. "It made a radical change in the conditions of transportation East and West, and it made possible the Memphis bridge and the future New Orleans bridge."
And in another direction yet it is peculiarly important. In bridge-building it marks an era, not only because of its strength and beauty and the daring of its design, but also because of its many labor-saving devices, the inventions of a thoroughly practical mind. A distinguished engineer calls it "a great pioneer in the art of sinking deep foundations and building spans over wide stretches of space, that astonished in its construction the entire civilized world." London "Engineering" chose it, while building, as preëminently the "most highly developed type of bridge;" and says, "In that work the alliance between the theorist and the practical man is complete." In Eads it finds its long-sighed-for dream, combining the highest powers of modern analysis with the ingenuity of the builder.
IV
THE JETTIES