I don't know why but this post disappeared after about two hours last night.
So. this is a repost.
After the candle or more likely along with the candle came oil lamps. This one was a foot light. You know the one that gives you the flashlight under the chin look. In fact foot lights are very seldomly used today.
You can see the filler cap in the center. The thumb screw secured it in place so that it didn't get kicked into the orchestra pit. Facing the audience was the shield that kept the light out of their eyes. Because this fixture was built out of galvanised sheet metal the shield would have been a lousy reflector.
There are five 1/4" round wicks. It is difficult to compare the amount of light produced because of the many variables but it appers that 5 candle power is a good approximation for a 1/4" round wick. That means that this fixture produced somewhere around 25 candle power. The average incandescent 100 watt bulb produces around 150 candle power. That's not very bright by todays standards.