The Cambria Iron Company have several acres of gravel and clay to remove from the upper end of its yard. Except for an occasional corner of some big iron machine that projects above the surface no one would ever suspect that it was not the original earth. In one place a freight car brake-wheel lies just on the surface of the ground, apparently dropped there loosely. Any one who tries to kick it aside or pick it up finds that it is still attached to its car, which is buried under a solid mass of gravel and broken rock. Several lanes have been dug through this mass down to the old railroad tracks, and two or three of the little yard engines of the iron company, resurrected with smashed smoke-stacks and other light damage, but workable yet, go puffing about hardly visible above the general level of the new-made ground. The progress of the work upon the black and still smoking mass of charred ruins above the bridge is hardly perceptible. There is clear water for about one hundred feet back from the central arch, and a little opening before the two on each side of it. When there is a good-sized hole made before all three of these arches, through which the bulk of the water runs, it is expected that the stuff can be pulled apart and set afloat much more rapidly. Dynamiter Kirk, who is overseeing the work, used up the last one hundred pounds of the explosive early this afternoon, and had to suspend operations until the arrival of two hundred pounds more that was on the way from Pittsburgh. The dynamite has been used in small doses for fear of damaging the bridge. Six pounds was the heaviest charge used. Even with this the stone beneath the arches of the bridge is charred and crumbling in places, and some pieces have been blown out of the heavy coping. The whole structure shakes as though with an earthquake at every discharge. The dynamite is placed in holes drilled in logs matted into the surface of the raft, and its effect being downward, the greatest force of the explosion is upon the mass of stuff beneath the water. At the same time each charge sent up into the air, one hundred feet or more, a fountain of dirt, stones, and blackened fragments of logs, many of them large enough to be dangerous. The rattling crash of their fall upon the bridge follows hard after the heavy boom of the explosion. One of the worst and most unexpected objects with which the men on the raft have to contend is the presence in it of hundreds of miles of telegraph wire wound around almost everything there and binding the whole mass together.