Rushlights were the lighting choice of the poor - very low cost, but not very bright, and may be slightly smelly (because of the tallow). Used from ancient times through to the 19th century where they were still common. They were still used in the 20th century in some rural areas.
A pith-filled rush is cut, and soaked in tallow (rendered animal fat) so that the tallow soaks up into the pith. The rush is then dried, and when needed, put in a stand and lit, and slowly burns down like a candle.