For years this handsome scene of maritime action in the Penobscot Marine Museum in Searsport, Maine ( www.penobscotmarinemuseum.org ), bore the information: “Two brigs engaging during the War of 1812.” Recent research, however, has revealed that it is of a far rarer subject: The ship in the foreground is a slaver.

The rendering shows one of the Royal Navy’s brigs in hot pursuit of a Baltimore clipper-style brig. The painting, bought in Britain, came to the museum in 1962 with no information other than the artist’s name, E. Poulson. The slaver has the raked masts and the sizable rig developed in Baltimore clipper ships during the War of 1812 and popular for decades afterward among owners who needed speed. This particular brig has a figurehead, possibly a witch, that may someday lead to identifying the ship.

Poulson’s paintings are rare; they appear in just a few museum collections. He is thought to have been a master mariner, possibly a Royal Navy officer, painting from about 1840 to 1865 while living in retirement in Sunderland on the North Sea. He might well have witnessed or participated in a chase such as this while on active duty.

The scene is fascinating, depicting a dramatic moment in a despicable business. A sudden squall, possibly assisted by a cannonball, has just split the slaver’s fore-topsail. Men are racing aloft to take it in and perhaps to finish setting the lower sail. On deck, remarkable details tell a further story. The slaves are being taken from the hold and forced to sit beneath the windward rail to improve stability and increase speed. Gathering the slaves on deck would also have made it easy to throw them overboard, a not uncommon practice when a slave ship was in danger of capture.

Careful examination has shown some of the slaver’s crew to be Africans. They played a role in the slave trade, often corralling captives for white buyers. Although data on the racial composition of captured slavers is hard to find, the crew Poulson depicts may not be unusual. Did this slaver escape? Or was she captured, perhaps to be turned against her fellow slavers?