Photo of a 1912 bicycle/phonograph shop

[gramophoneshane]

The lights on the photo look to be electric lights. On an electric light, the glass shade faces down. On a gas light, the shade faces up. There is a combination fixture called a gasolier. You can tell because it is both electric and gas. Like I said before, the shade is up on a gas light, and down on an electric light. So on a gasolier, you will see both styles of shade on one fixture.
Harvey Kravitz

Not always. Some of the larger gas lights had the shade pointing down, like those designed for over billiard tables, so I'd assume gas lights in a large shop with high ceilings would also have the shades open at the bottom to help direct the light downward.

[Lenoirstreetguy]

They're GAS lights...inverted mantle gas lights..with the mantle like those in a Coleman lantern...you guys never listen to a word I say Look at this page from the March 1908 issue of The Illuminating Engineer. See??? Inverted GAS lights in a combo fixture. The ones with the bigger shade ring are gas. G-A-S You can read the text of the article as well.

Your gassy old buddy,

Jim