Combination oil and gas chandelier?
I just picked up a great chandelier over the weekend for the front hallway of my 1857 home. However, I'm a little confused by it. It appears to be a gasolier, as it has keys and glass gas shades. However, it also has oil fonts and glass chimneys that fit inside the gas shades. Both the gas shades and the chimney shades are original. Was this a combination fixture or was it an oil fixture meant to look like gas? Also, can anyone date it for me? I was thinking 1880s because of all the prisms but I really don't know.
I've attached a couple photos. Thanks in advance!