The English - Birmingham - proof stamps are by the barrel key lug. Under the cross sceptres you can see the letters BPC [Birmingham Company Proof] on the barrel and V [View] on the receiver. The pistol dates from between 1840 and 1860, and was made by the thousand for personal protection. Popularity for personal defence pistols for ladies dropped, though, with the widespread growth of the railways, which rapidly replaced instead of stage-coaches as the most popular and cheaper form of travel. A stage coach is pretty easy to hold up at gunpoint - a train, well, not so much.
a couple of years back I got to shoot a rifled version - very unusual, too. It was around .45cal, and, as mooncoon notes was loaded by filling the chamber in the receiver and placing the unpatched ball in the cup-shaped receptacle and screwing the barrel back on. The charge was around 18gr and it had a formidable amount of recoil - totally rotating in my hand. There is no doubt that at the usual distances of around five feet it was going to cause a lethal wound - young ladies were advised to aim directly at the face of the threat.
Here in yUK if you have one of these little pistols and wish to shoot it, it must be registered on your Firearms Certificate as a Section 1 live-firing firearm, or else you are in a world of trouble. It's a RPITA, but, the law is the law.