The Gas Chandelier Period began in the 1850's and followed the use of fluids (e.g. kerosene, oil) to power chandeliers. Gas was manufactured from coal. This was an improvement from a safety point of view because fluids would tend to flow and drip to cause fire hazards.
A typical gas chandelier (e.g. 3 arm gas chandelier) would have 3 arms with bowl shades on the end of the arms housing a gas flame that would light the room . The wattage output from gas chandeliers was fairly low.
Antique Gas fixtures can be placed in many of the rooms in your home and vary in size and detail.