My wife and I are on the seventh of the Aubrey-Maturin books, The Surgeon’s Mate (which means we’re eating them up at a rate of almost one a month—see this post for the start of the voyage—and will have finished the series sometime in the spring of 2013, and what will we do then?), and when I read the start of Chapter Three, “The Diligence tided it down the long harbour during the night, and before daybreak she was clear of the Little Thrumcap,” of course I had to know where and what the Little Thrumcap was. The Nova Scotia Pilot provides the answer [text below the cut for those who can't see the Google Books image]:
But another question remained: what’s a thrumcap? Here we turn to the OED and find “Thrum… A short piece of waste thread or yarn…; pl. or collect. sing. odds and ends of thread… thrum cap, a cap made of thrums.” You can see a couple of illustrations (including one from the movie Master and Commander!) here, as well as read “The Ballad of the Caps” (“The Saylors with their Thrums do stand/ On higher place than all the land”).
Oh, and here‘s a splendid painting, “H.M.S. Shannon Leading Her Prize the American Frigate Chesapeake into Halifax Harbour,” in case you too are a devotee of O’Brian and would enjoy seeing such a thing.
The Nova Scotia Pilot quote:
Little Thrumcap Islet, about 2 miles westward of Devil Island, is 33 feet high and 300 yards long, and connected with the southwestern extremity of Macnab Island by long shingle beaches, inclosing a shallow lagoon; its cliff of red sand and clay is fast wasting by the action of the sea. Big Thrumcap is 800 yards northeastward of it.