This revolver is based on Robert Adams' August 22, 1851, patent. The Model 1851 was the first commercially successful double action revolver but lacked the ability to fire in single action. Like many Belgian firearms makers, the Pirllt Brothers of Liege were fond of using the designs of gunsmiths from other nations. However, unlike many Belgian copiers, the Pirolt Brother arms were known for high quality. They were active from the 1830s into the 1870s. Some of their arms were likely imported into the U.S. and used during the Civil War. This revolver was manufactured on license through Deane, Adams & Deane as confirmed by the "MANUFD BY PIRLOT BROTHERS LIEGE LICENSED BY DEANE ADAMS & DEANE LONDON" marking across the top strap and barrel. The firm also manufactured some licensed copies of Colt's revolvers which is interesting given that Adams and Colt were intense rivals in the European market. The success of Adams' designs ultimately forced Colt to close their London Armory just three years after it opened. The barrel marking indicates the revolver was manufactured between 1851 when the design was patented and 1856 when Adams left to start the London Armoury Company. The right side of the frame under the cylinder is marked "ADAMS S, PATENT No 9851." Both of these markings are hand engraved. The matching serial number is marked on the side of the cylinder. A "crown/U" proofmark is stamped on the barrel on the left at the breech, and additional proofmarks are on the rear face of the cylinder between the nipples. The left side of the frame has a "crown/PF" stamp and "ADAMS/1851/PATENT" marking. Nearly all of the metal surfaces are covered with detailed leafy scrollwork engraving and punch dot backgrounds. The grip has silver stud accents, demons, mythical beasts, and floral designs. Demonic figures and the occult were particularly popular themes in the Victorian Era. The revolver comes in a two level case. The upper section is a French fitted insert for the revolver, powder flask, bullet mold, oiler, wrench, screwdriver, jag, patch cutter, and bore rod and also has a compartment with a cap container and the key. The two lower compartments have wooden lids and contain a measurement chart for wire, rope, chain, and other items; a compass with the headings to various locations, a magnifying glass, folding ruler, two protractors, small ruler, and a set of draftin/cartography tools.