They were commonly made of iron or brass and were most often used in the home or workshop.
These lamps burned fish oil or fat trimmings and had wicks of twisted cloth.
This internal wick holder feature made the Betty lamp design very popular.
Adding a top cover provides protection of the lamp's oil from insects, minimized spills and increased burning efficiency.
They are popular with living history buffs and people living in developing countries that are lacking other resources[citation needed].