That looks like my first pistol!
When whale oil became hard to get I started using a battery powered lantern. Now I use a small handheld flashlight in my off hand. That way I don't have to point the gun to check an area out.
Here's another oldie. I doubt it worked very will though. Those old sliding contact side mount switches were a weak design point. I'd guess he probably just switched to a 6 volt battle lantern held by a gun bearer.
I suppose that the earliest weapons light would have been a hand held fire torch, with a spear, or club held in the free hand. If we follow a Darwinian model for a thought experiment, this could explain a lot in regard to who we are today.
In the good old days, everyone hid in the cave after the sun went down, so, only the bravest would pick up a torch, & go outside to see what all the racket was about. Since a torch & sharp stick is really no match for big teeth & sharp claws, it's likely most of them became cat food. And, since if you get eaten, your genes don't get passed along, so, we can conclude that the current population is largely descended from scaredy cats that stayed in the cave.
Now, if we can just convince those that are clinging to their safe zones, to just buy a good weapons light, we might get evolution back on track.