This is a flint and steel lighter, made of brass, steel, and flint and measuring around 10.75″. It performed the same function as hand lighters do today. This piece was once owned by John Trumbull, Aide-de-Camp to George Washington. For source and more details, click here.
Image from: http://www.cr.nps.gov/museum/exhibits/revwar/image_gal/morrimg/lighter.html