Merwin, Hulbert & Co. revolvers were made by Hopkins and Allen. They have a unique loading system that involves the front of the frame unlatching and turning to allow the barrel and cylinder to be pulled forward. When this happens, the cartridges are kept back by a ring on the frame. The M&H cartridge case length is sized so that the fired rounds will drop free, while the loaded rounds will be kept in the cylinder by the bullet. (Other cartridges, not made for the M&H, won't work that way.)
Loading is through a loading gate with the gun closed; the gun can't be loaded by dropping rounds into the cylinder as with topbreaks.
M&H guns had a very good reputation and are beautifully made. The early ones were SA, but later guns were DA. The large frames were chambered for .44-40 and for .44 M&H. The pocket models were made for .38 M&H and .32 M&H; .38 S&W and .32 S&W will fire, though the M&H extraction system won't work right (see above).
There was also a SA .22 revolver, resembling a S&W No. 1; why an essentially obsolete design was made as late as 1880, I don't know.
One interesting feature which M&H had as an option, and Hopkins and Allen copied in their own guns, was the folding hammer spur. This allowed the gun to be drawn easily without the hammer spur catching on clothing, while still having the capability for cocking the hammer in single action fire.
The large frame models bring fairly high prices, over $2000 for a nice specimen, but their pocket models are very reasonable, going for a top of around $500-600. They are nice additions to a collection.
Jim
