As he spoke he thrust down his pole, which must have been jammed in a hole, and his weight being thrown upon it, before he could recover it broke, and over he went; I in my eagerness, leaning on one side, attempted to grasp at him, the consequence was that the canoe, swinging round, was driven by the current against the rock.  I heard a crash, the foaming water washed over us, and I found myself struggling in its midst.  My first impulse was to strike out, for I had been a swimmer from childhood.