The Gas Lamp is a light-source spending white light that you can craft yourself (in your Crafting Menu, default key "Q", or at any old Crafting Table in in worlds created before R22 on September 16th 2015) after unlocking it by taking/crafting a Wood Burning Lamp for the first time (for example as a finding in Diamond Treasure Chests or loot/harvest from the Thing). To craft 4 Gas Lamps at a time, you'll need (as of R22 in September 2015):