Read it through once

'A rise starts the drift-wood, but then it keeps on floating a while after the river is done rising. Now the bank will tell you about this. Wait till you come to a place where it shelves a little. Now here; do you see this narrow belt of fine sediment That was deposited while the water was higher. You see the driftwood begins to strand, too. The bank helps in other ways. Do you see that stump on the false point?'