Seized from their posts, French prisoners of war in the 18th and 19th centuries were left to build themselves new ships. But these were tiny model vessels, carved in exquisite detail from bone.

Receiving daily rations of half a pound of meat from their British captors, the Frenchmen would whittle the leftover bones into recreations of the ships they had manned themselves during the Napoleonic Wars. These models pack stunning complexity into, typically, just 30 to 40 inches (and sometimes less).

The hulls seem almost to breathe, gracefully curving outward as they approach the decks. Dozens of cannons poke neatly out of a single side, not wedged into their individual ports but held in place by an invisible mechanism. Bowsprits project forward at a noble angle, tapered masts stand straight and tall, and full-bodied figureheads even sit on rigging made from human hair, their minuscule fingers curled around swords and their button faces chiseled into distinct features.

All this, of course, was done from memory. While many of the models are painted, some of them remain bone white, the only indication of their humble origin.

Because prisoners of war had not technically defied British law, and their sentences were contingent on the course of the conflict, they were often treated with more lenience and respect than criminal offenders. Some of them converted their sentences into business opportunities, selling their ship models to the general public and leaving prison with substantial fortunes. Today, one of these ships can fetch tens of thousands of dollars at auction—so take out last night’s leftovers and get to work.

If you can’t figure out how to build your own miniature boat from bone, you can head to the Channel Islands Maritime Museum in Oxnard, California. The museum has nine of the ships on display, forming the second largest collection in the United States.