Thoreau writes in his journal:
Rice has had a little experience once in pushing a canal-boat up Concord river. Says this was the way they used to get the boat off a rock when by chance it had got on to one. If it had run quite on, so that the rock was partly under the main bottom of the boat, they let the boat swing round to one side and placed a stout stake underneath, a little aslant, with one end on the bottom of the river and the other ready to catch the bows of the boat . . .