Scenes to fit the song and look at longer, sometimes serene, sometimes bustling with the activity that shows up so well in the films made from Mr. Spier's books. At "Low bridge, everybody down!" a laggard is bound to be lopped off; but every fifteen miles more or less there's a lock to navigate, a passing barge, a welcoming town, maybe even a rest for old Sal. A page at the close summarizes the history of the canal and answers likely questions (while raising another: why mention "remnants" of the old canal and ignore its replacement?); another gives the words and music of the song. Historical recreation with a jaunty air.