Mr. HENDERSON. I care not how it may be done, provided the bridge is put 50 feet above high water mark, so as to enable the steamers to pass beneath the bottom chord of the bridge. I do not ask that it shall be built in one or the other mode; we only ask that it shall be built in continuous spans, and if they want to use iron they can do so. But let me propose to the Senfrom Minnesota, whose section of country is very rapidly growing into great importance, that in the course of a few years a great change has come about. in the transportation of prod ucts upon the Mississippi river, much of which comes from his own thriving State. Instead of loadin down a packet and running it throughz a towout is taken, with a large number O barges, requiring much more space than for merly in the trauspmtation of the productions of that section of country. He will remember anothor difficulty, and a very serious one with us. From the State of wise Onsin, and his own State, perhaps, a large quantity of the lumber used in our section of country is brought uion the surface of the Missis sippi river. hese rafts are sometimes 300, 400, or 500 feet in length, and repeated difficulty in getting them through between the piers of a bridge has been experienced at the town of RockIsland. He may say that a raft is never so wide as 250 feet. I do not know in regard to that, but I know that some of them are very wide. He will remember, however, that the current in high and low water is not always the same on the Mississippi or any other stream. The passage of rafts between the piers of these briges will certainly require a space of more than 250 feet. Perhaps the Senfrom Minnesota can enlighten me on the subject, but if I am not much mistaken, in high water, when the current is strong, and when the rims themselves are not ima line parallel with the current of the river, a raft may be started through properly, but before the entire raft gets through it will strike the piers, as has frequently been the case at RockIsland, if I am notmistaken.