"Uncle Josiah and old Uncle Sam, they built them a sloop in the shape of a clam." The sloop is finished and launched but they find that they can't sail her. After much trouble they get the boat moored and swear they won't build any more.
The idea of a ship in the shape of a clam isn't as ridiculous as it sounds. It has been done -- admittedly with mixed success. In the 1870s, the Russian admiral Andrei Aleksandrovic Popov designed the "Popovkas" (or "Popoffkas") -- battleships (eventually named the _Novgorod_ and _Admiral Popov_) with circular hulls for maximum stability as gun platforms. Lincoln P. Paine's _Ships of the World_, p. 424, says they worked well enough, but Richard Humble, _Battleships and Battlecruisers_, p. 41, reports they could only be steered into a current: "They spun like tops when coming downstream and their decks were flooded by the slightest seaway."
A later vessel, elliptical rather than actually circular, proved better. Fritdjov Nansen's _Fram_, built in the early 1890s, was designed for polar exploration; Nansen and Sverdrup used her to make what amounted to a Northeast Passage (see, e.g., Pierre Berton, _The Arctic Grail_, pp. 489-498, especially p. 495), and Amundsen later took her to the Antarctic. But the honest truth was, she wasn't much good for ordinary sailing; her round sides and rounded bottom were designed to keep her from being crushed by ice, and made her very slow and almost useless for other tasks. - RBW