The Question and Answer section for Three Men in a Boat (To Say Nothing of the Dog) is a great resource to ask questions, find answers, and discuss the novel.
As the three men approach Goring, they spot a dead woman floating in the water. Some other travelers take her to the coroner, but J. later learns that she killed herself after having a child out of wedlock and being abandoned by her family.
They were sitting in a meadow eating beef steak pie just ten yards from the water's edge. All of a sudden, Harris disappears. Harris actually sunk into a marshy pond and only his head was sticking out.
There is no such place as "Maclow" mention in Chapter 13 of the text.