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.