This is a Spur Trigger Pocket Revolver in .22 Caliber by Jacob Rupertus of Philadephia, PA. According to Flayderman's Guide to Antique American Firearms, Rupertus only built about 1,000 of this model in .22 caliber during the 1870s and 80's. This particular example is nicely engraved with original ivory grips. The barrel is marked "Empire PAT NOV. 21. 71." The barrel, cylinder, and front portions of the frame are more panel type engraving with geometric designs bracketed with scooped floral patterns similar to Merwin Hulbert revolvers...which were often filled with colored enamels. The rear of the frame is more in the style of Nimschke with floral vignettes with punch dots in the background.
The mechanics on this gun are a bit unique. When's the last time you saw a pocket revolver with stop notches are located on the face of the cylinder? Sure, you'll see the notches on the back of the cylinder with the ratchet or milled cuts on the sides, but I can't ever recall seeing a revolver with notches across the front face. In order to function, the locking bolt has to be located down in the bottom corner of the frame. The bolt operates from a thin lever extending across the bottom strap from the spur trigger. A bolt has to have good spring tension in order to operate properly...and back in the 1870's, just about every kind of mechanical tension you could imagine (with some exceptions) was usually in the form of a leaf type spring. Sooner or later, these little leaf springs always wore out and you ended up with cylinder that might line up just fine with the barrel, but floated...a potentially dangerous situation if moved before firing. Rupertu came up with something that was probably much better in terms of durability. Instead of leaf springs, he tensioned his cylinder bolt with a coil spring which he was placed in a small shaft bored inside the front lug directly above the cylinder stop. It works just like a shock absorber or a spring inside a ball point pin and probably never wore out.
Overall condition is NRA Antique Good+. The edges and engraving are slightly worn which leads me to think that the finish, which is about 60% that's nicely blended with gray metal from honest wear probably a very old re-nickel. Being so old with wear, its not gaudy and doesn't take away from the overall appearance of this weapon. The ivory grips are solid with zero chips, cracks, or repairs. Nicely yellowed with age. They fit the straps and the frame perfectly. No question that these are the original grips that came on the gun. Mechanically, this Rupertus is in very good condition, indexing perfectly, locks up...even the half-cock notch works. A very attractive engraved Rupertus Revolver.