The Betty, from the German word "besser," meaning better, was designed to improve the performance of grease lamps by creating a wick holder in the base of the lamp which allowed the drippings from the wick to run back into the bowl and be consumed. A cover was added to the lamp which further improved it by confining heat, decreasing smoke, and making the oil burn more efficiently.
Various forms of the Betty Lamps were designed and used in the 18th and 19th Centuries.