For removing the bridge I would observe that nearly the same time is required to disconnect the raft from the abutments, about the same time to swing the raft, and for dismantling and placing the roadway on the shore about four or five minutes only, or about fifteen minutes all together for this removal. The squads of men, if the force were available, might be increased from 6 to 7 to 10 to 12 for each bay, which would still further reduce the time of construction and dismantling.
I have been thus particular in showing the delays, not to say opposition, that has been experienced, that, simple as the mode really is, and, as may be supposed, one that would be so readily seized upon, it might be seen how strong the prejudice was in favor of the old slow process, or what total ignorance there was of this mode or of its advantages.
Some of these advantages I would now respectfully call attention to, available as I feel assured it will be in whole or in part for the large majority of cases in actual practice. It would have answered perfectly, I know, for the three bridges which were laid at the United States Ford on the Rappahannock in April last, also at the Franklin's and the Reynolds' crossing, 2 and 4 miles, respectively, below Fredericksburg, where our bridges have been laid repeatedly. It would have applied partially at Banks' Ford, where Sedgwick's troops retired on May 5; also partially and to a greater extent when these same troops were crossed at Edwards Ferry on June 29, 1863, when it would have been of great importance, the river being over 1,400 feet wide here. The old method required some six to eight hours (as reported to me) for the construction of each of the two bridges there, and the labor of carrying upon the shoulders of a limited number of men of these roadways in parts for the space of over one-eighth of a mile, while by this method this labor of carrying the material is needed for from 10 to 20 or 50 feet only.
It also enables the material to be used by the largest number of men from the position where it can most speedily be unloaded from a land train, the wagons and trucks of this train being unloaded at once from the positions of the train as wheeled and closed in a line on the river bank. Or if the bank did not permit the easy approach to the wagons the loads can almost as quickly be distributed there by the large number of troops usually unoccupied while waiting to cross. While the old method required the piling of the whole bridge train by the successive loads as they arrived, around a single abutment, as well as the carrying of this material to be laid, by one or at most two squads of men for ordinary bridges, while all the rest of the command were in a forced idleness.
But more than this, it can carry, fully concealed from view of sharpshooters, a storming column of men equal in number to every foot to its length, as every pontoon can cover, under the bridge floor, or concealed a foot below the gunwale, at least 20 armed men besides its crews (of which the one or two oarsmen only need be exposed), so that as the raft (previously made of full length) comes directly across the stream and grounds at either bank, these men rise, an armed storming column debouching at the instant from the bridge, to be followed in a continuous stream by other troops from the pivot shore, and in power to sweep away everything except the heavy masses of infantry or artillery well posted, in the face of which, of course, the construction of any bridge would be next to impracticable. After the opposite bank shall have been cleared of