Kitabı oku: «James B. Eads», sayfa 3

His mind was as active as his heart was generous, and the course of his life mirrored that activity. Now he was at home, now in Washington, now at Cairo visiting the gunboats to see how they worked under fire. In Washington he was busy with plans and projects. An intimate associate said of him in his later life that he was always inventing some new gun or gun-carriage; and we may be sure that if he ever was doing so, he was in those war times. Besides inventing his own, he was also busy examining Ericsson's inventions, in making improvements on them, in applying steam in novel ways to the working of artillery and to the rotating and raising of turrets; in sending models of his inventions here and there, at home and abroad, to Germany, where the Prussian minister, a friend with whom he often dined, "wished they could get some of his boats on the Rhine;" having his turrets explained at a Russian dinner in New York or Washington; and receiving from the Navy Department an appointment as special agent to visit the navy yards in Europe. At home he was just as busy. With his house so full of company, he nevertheless found time somewhere for solid reading apart from his work—the Attorney-General sent him Cicero's letters, and he lent the Attorney-General King Alfred's works. There is a curious interest in knowing what two men so engrossed, and upon such necessary duties, were reading at such a time. While he was building the second batch of gunboats, he wrote to Bates in a personal letter that he believed he had the most complete and convenient works in the country for iron boat-building; that there and in other places he had as many as seventy blacksmith fires at work for him, and that his men were all sheltered from sun and rain. After those boats were finished, he went on planning others, and we have a letter from Farragut in which the admiral asks if some of them are not for his use at Mobile.

Eads, by this period in his strenuous life, knew a great many men, all of whom he treated with a uniform dignity and courtesy, even when they were unfriendly, and a few of whom he was on the most intimate terms with. Among all of them he was admired; perhaps already he was as prominent a citizen as there was in Saint Louis, and as it was still in the good old times when the mayoralty there was a high honor to the best men, it was suggested to him that he hold the office. Nor was this the first honor offered to be thrust upon him; early in the war Bates had wanted him appointed commissary of subsistence at Saint Louis, and though it was unusual to appoint a civilian to that position, Lincoln had been willing to do it to oblige Bates,—but Eads had not wished it. More than a year later he was given a commission of lieutenant-colonel by the governor, but he was never sworn in. Like all men in those troublous times, he took a peculiar interest in politics; and on being asked privately in a joint letter from the editors of three Saint Louis papers (two of them German) exactly what his politics were, he replied that he was as strongly in favor of emancipation as he was opposed to slavery, and that he believed in no "kid-glove policy;" but he remarked incidentally that if he were to be offered the mayoralty he should refuse it.

His work was for the whole country. While he was still too much engrossed with his turrets and his plans for new boats, he fell very ill. Indeed there can be no question that he sacrificed his health to build the gunboats. Never very robust, he was now so ill that eight doctors gave him up. His indomitable spirit pulled him through, but he was ordered away from his workshop to Europe, he and his family. His overburden of labor had crushed him,—before this his eyes had been tired out. Bates charged him to take care of himself; "the country can't spare you," he said "and I can't spare you."

Unless Bates was a prophet, we may well think the first of these statements unduly strong. To be sure, when in a crucial moment the gunboats were needed, and needed quickly, Eads's unparalleled haste in building them certainly did an inestimable service to the country. But so far in his career,—and he was over forty,—while he had shown a marked inventive talent, he had not as yet made clear his signal genius for engineering. And although he had exhibited wonderful executive ability and such true patriotism as made him a valued citizen, he had still to render himself indispensable to the development of the nation.

III
THE BRIDGE

Eads was bred to the Mississippi. He had mastered its secrets by hard experience; he had worked in successful opposition to its great wayward forces. But he was not to be content till he had tamed it, till he had saddled it, and, wild as it will always be, had made it nevertheless subservient to him. To his quietly stubborn spirit there was a delightful invigoration in using his brain to conquer the brute force of this capricious monster. For the river is the grandest power between our two oceans. Niagara is more sublime; but Niagara is constant, and therefore its immense strength has been easily set to a task. The Mississippi is so irregular that one tends unconsciously to personify it by calling it tricky. To find the causes of its sudden changes one must go back hundreds of miles to the mountains east and west. Seeming to delight in destruction, it tears down or eats away the checks that are put upon it. Only a mind never discouraged, a mind capable of discovering and comprehending the laws that after all underlie the apparently blind and brutal jests of this untiring giant, can, by the use of those very laws, tame it. And such a mind Eads had. "That everlasting brain of yours will wear out three bodies," said one friend.

Though indeed his body was strong, with iron muscles and a fierce nervous energy, yet it was not a big body, and his health was weak. Again and again he worked beyond his strength, and only on the absolute order of his doctors would he go away from his work and rest. But he could not entirely rest. His brain would work. In his health tours to Europe he was always open to new ideas, always studying new methods to carry back to his task. "Your recreation," some one wrote him, "is Monitor discussions with Captain Ericsson." Another recreation was chess. Had he not elected to be the leading engineer of his day, he might have been the chess champion. This game, never one for the slothful and unthinking, he made even more exacting than usual. He would play several games at the same time; or, without seeing the board which his opponent used, he would carry the game in his head. Though it was his nature not to like to be beaten, yet he was as kindly as he was set in his purpose; and it was also his nature to take defeat gracefully: defeat seldom came. "Never let even a pawn be taken," he gave me, a small boy, as a rule for the game. Even in little things he liked thoroughness,—a capacity for painstaking which is, I think, characteristic of the "thoroughbred."

His appearance showed his traits. Not tall, and rather slight, he was always dignified. His wide and thin-lipped mouth shut so emphatically that it made plain his intention to do, in spite of all, what he believed could and should be done. Some one said that it was a hundred horse-power mouth. It admitted no trifling. When it spoke seriously, it spoke finally. But his eyes, with their merry twinkle, showed that he could also speak humorously. He was indeed a famous story-teller, fond of all sorts of riddles and jests, and remembering all of them he heard. He used often to point his arguments with an anecdote, always a fresh one. Believing with Lamb that a man should enjoy his own stories, he would laugh at his in a most infectious way, till he was red in the face. Indeed, he was the larger half of his stories. His face was thoughtful and stern. Though he seldom found fault, he never did more than once; but he was by no means violent. His mildness was more forcible than anger. He wore a full beard, but no mustache, thus exhibiting his long, determined lip. At forty he was already bald, and after he was sixty he always wore indoors a black skull-cap. Scrupulously cleanly, in his dress he was point-device. Without the least ostentation, his clothes were invariably faultless. From young manhood he had thought that it is due to one's self and to one's friends to look one's best; and he had also realized the practical value of a good appearance. Often impressing this on his wife and daughters, he would have them at all times well dressed. Really he seems to have been a point too precise. He was just the opposite to those geniuses whose great brain shows itself by a sloppy exterior. Eads was never sloppy, even at home.

His great brain showed itself in its restless activity, in its grasp of laws and of details, in its fight to help and to better the country and the world. For it was not only the lusty pleasure of battling with Nature that made him long for another struggle with the Mississippi: he saw the value there was in it to commerce and to civilization. Before the war he had long contended with stubborn currents, and with ice, and by his energy and his talent for inventing new devices he had become the most successful wrecker on the river. Abandoning the peaceful but lively triumphs of snatching hulls and cargoes from the maw of the stream, he had offered the government to cleanse its course and thereby to increase its safety and usefulness. In war times, owing to his knowledge of the waterways and of science, he had been able to build, with a speed fairly romantic, a gunboat fleet to patrol the Mississippi. Already now greater schemes for improving this central highway of our country were in his mind, but as yet the fullness of the time was not come. Still, he was no longer merely the careful son and father striving to protect his beloved ones and with no dreams of broader duties; he was no longer contented with rose-arbors for an occupation. The grim war had roused him; his years of rest were over; he was the well-known boat-builder,—engineer, perhaps some persons already called him,—and his mind was teeming with schemes of helpfulness. Yet his ambition was not for fame, but to do in the perfect way the work that only he could do.

In 1867 a grand convention for the improvement of the Mississippi and its tributaries met in Saint Louis. Even then people were beginning to see vaguely that the Mississippi Valley is destined to be the ruling section of the country. Eads in his speech showed that he foresaw it plainly. He urged the convention to persuade the government to take steps to improve the river; showing that for less money than was paid by the river boats in three years for insurance against obstructions, those obstructions could be removed. There was not one of them, he said, that engineering skill and cunning could not master.

Two years later he urged upon the commercial convention at New Orleans by letter the importance of introducing iron boats on the Mississippi; saying that it was the fault of the tariff on iron that the saving they would effect was not taken note of. Thirty years later this scheme has again been brought up. Perhaps Eads was before his time in advocating it. But it shows how he had the interests of commerce at heart.

His convention speech is a good sample of his style. He was so painstaking that even in private letters he would insert words and change sentences and sometimes rewrite. There are first draughts with excisions of whole half pages, for he sought conciseness. He sought also a certain rhythm or grace or forcefulness, it is hard to tell exactly what, since in his letters it often resulted in a rather self-conscious formality or a stiff playfulness, and in his speeches in a prettiness or a floweriness of style. He sought too carefully. Probably in delivery the speeches sounded better than we should imagine. In reading them, they seem florid. That was, however, the favorite style of the time. And while, by overdoing it, he often seems to lose force, he is almost always clear and always entirely logical. In contrast to his speeches his professional reports are models: simple and complete, written not faultlessly perhaps, but with a limpidity which makes one interested even in dry technical details. One of his most marked talents, often noted, was the ability to explain an abstruse subject so that it would be quite clear to anybody. And this he did nearly as well in writing as by word of mouth.

He thus made clear his remarkable plans for the bridge; for in 1867 the long talked of bridge at Saint Louis was at last begun.

In 1833, when Eads had arrived at the town, it had about 10,000 inhabitants. Though already seventy years old, it had not advanced very far beyond its original state of a French trading-post. With the introduction of steam and the waking up of the country, the growth of Saint Louis was rapid. In 1867 it had about 100,000 people. Despite a commanding situation, it could be seen that a struggle would have to be made for it to maintain the leadership among the river towns. As early as 1839 there had been a project for a highway bridge; and we are told that "the city fathers stood aghast" at an estimated cost of $736,600. In the following years there were several more abortive schemes for bridging, one of which, it is even said, would have been carried out, had not its projector died. Perhaps it is as well that he never lived to try it, for until Eads no one seems to have realized how enormous the undertaking was. Probably few others, realizing it, would have dared to go on.

In the winter of 1865-66 a bill was brought up in Congress to authorize the bridging of the Mississippi at Saint Louis. Dependence on ferries had become intolerable to the people, and often when the river was frozen even the ferries were blocked. A bridge was felt to be absolutely indispensable. However, the antagonism of rival commercial routes was so powerful that the bill was allowed to pass only after it had been so amended that it was supposed to require an impracticability. It declared that the central span of the contemplated bridge must be no less than 500 feet long, nor its elevation above the city directrix less than fifty feet. It was said at the time "that the genius did not exist in the country capable of erecting such a structure."

Still, a span of over 500 feet had been built in Holland; and the fact that there was not a total doubt as to the practicability of doing as well in the Mississippi Valley is shown by the inauguration of two rival bridge companies about a year after the passage of the bill. One of these, which was located in Illinois, after calling a convention of engineers, who considered the question for ten days, without an examination of Eads's plans, adopted a plan for a truss bridge. The other, the Saint Louis company, from the first had Eads as its chief engineer. For another year there was a sharp contest carried on between these two companies, confined, however, principally to the courts and the newspapers, until finally the Illinois company sold out to the Saint Louis company. Had the truss bridge been built, there is no knowing how long it might have stood, for the engineer who designed it did not arrange to base the foundations on the bed-rock of the river. Afterwards it was shown how necessary it was to do this; but at the time many people thought it quite superfluous, and on that, as well as on many other points, Eads met with opposition.

In every case it turned out that he had been right. No one else knew so well as he the immense power and the waywardness of the Mississippi. Good engineers supposed that the greatest imaginable scour at the river bottom in extreme high water would not remove over twenty-two feet of sand, and it was believed that there were perhaps one hundred feet of it along the east shore. But Eads had been sixty-five feet below the river's surface at Cairo, and there he had found the river bottom to be a moving mass at least three feet deep; and in cutting through the frozen river to liberate his diving-bell boats, he had found that the floating ice which goes underneath solid ice, as well as the rising or "backing-up" of the water above ice-gorges, forces the undercurrents lower than even a flood does; and he had found on cutting a wreck out of the ice that she had been held up by the gorged ice underneath her, which must therefore have been packed to the bottom. Knowing all this and much more about what goes on under the turbid surface of the river, he did not doubt that even beneath 100 feet of sand the bed-rock might at times be laid bare, and he was absolutely convinced that his bridge must be founded on it.

Moreover, he saw that on account of the exceptional force of the current in its rather narrow bed at Saint Louis, the masonry piers of his bridge must be made unusually big and strong to withstand it. Since they must be so big and sunk so very deep, it was evident that they would be so costly that the fewer there need be of them the better. The central span was required to be 500 feet; with three spans about that length the river could be crossed, and three spans would require only four piers. Steel trusses 500 feet long would have to be made extremely heavy; but Eads showed that a steel arch the same length, while quite as strong, would be lighter and consequently much cheaper. When his opponents objected that there was no engineering precedent for such spans, while he pointed out their mistake, at the same time he expressed his conviction that engineering precedents had nothing to do with the question of length of span; that it was altogether a money question. Therefore, since the cheapest method was to be carefully sought, he determined upon arches,—two abutment piers, two river piers, and three arches of respectively 502, 520, and 502 feet long.

There were many opponents to this plan; some of them people who would have opposed any bridge, as, for example, the ferry and the transfer companies. To his own company he explained away every objection that came up, as he was bound to do, in view of their confidence in him. He made the clearest of explanations of the theories involved; and even such absurd predictions as that his superstructure would crush his huge stone piers, he took the trouble to blast sarcastically. To an engineering journal he wrote three letters correcting mistakes in its accounts of his work. But he seems to have wasted little of his energy in arguing with the newspaper public. It was a question only of time till everybody should be convinced.

The most extraordinary care and pains were expended in every direction. The stone, granite, and steel were both hunted up and tested by experts, and by machines specially devised in the bridge works, though not by Eads himself. For his assistants he chose men who were of real ability and well trained, and to them he invariably gave great credit for their part in the work. The plans, after being figured out in detail by them, were gone over by the mathematician Chauvenet, then chancellor of Washington University, who found not one single error in them. Most of the big work, such as the masonry and steel, was given out on contract; and, as was natural, delays by the contractors often greatly delayed the progress of the bridge. The whole work occupied seven years.

While Eads had promised the company to prove by careful experiment, so far as was possible, everything connected with the bridge that had not already been fully demonstrated in practice, he did not pretend that in his main outlines he was without some examples. It was in his development of known ideas and his expedients for simplification that his genius perhaps most strikingly showed itself. Again and again he contrived some device so simple that, like a great many strokes of genius, it seemed that anybody should have thought of it. The massive piers were sunk to the bed-rock by means of metal caissons. These were adapted in design from some he had seen in use in France, and had examined during a trip his doctors ordered him to make in 1868. Eads himself compared them to inverted pans. They were open at the bottom, but perfectly air-tight everywhere else. They had several important features which were entirely original. Such caissons, sunk to the bottom, have the masonry of the pier built on top of them even while they are sinking; and workmen inside them keep removing the sand from underneath, and throwing it under the mouths of pipes which suck it up to the surface of the river. Evidently the caissons must be filled with compressed air to equalize the external pressure, which is constantly increasing as ever deeper water is reached; they must also have an opening connecting with the surface; and to admit of passing from the ordinary atmosphere to the denser one, there must be an air-lock. Before this bridge was built, the air-lock had always been placed at the top of the entrance shaft, where, as the caisson sank and the shaft was lengthened, it had to be constantly moved up. Eads placed it in the air-chamber of the caisson itself, where it never had to be moved; and thus, as the shaft was not filled with compressed air, less was needed, and there was less danger of leaks. Another of his useful innovations was to build his shaft of wood, and another was to put a spiral stairway into it. Indeed, in the last pier he put an elevator into the shaft. Moreover, he was the first person to run his pipes for discharging the sand, not through the shaft, but through the masonry itself; and he invented a very simple and effectual new sand-pump, which was worked by natural forces without machinery. All these improvements and various others seem to have been thought of so easily, that we are inclined to wonder why clumsier methods had ever been in use. He described them all in his reports and his letters about the bridge in a style which is not only clear but actually fascinating even to a person who has scant scientific knowledge or taste.