A tromba marina, marine trumpet or nuns' fiddle, is a triangular bowed string instrument used in medieval and Renaissance Europe that was highly popular in the 15th century in England and survived into the 18th century. The tromba marina consists of a body and neck in the shape of a truncated cone resting on a triangular base. It is usually four to seven feet long, and is a monochord. It is played without stopping the string, but playing natural harmonics by lightly touching the string with the thumb at nodal points. Its name comes from its trumpet like sound due to the unusual construction of the bridge, and the resemblance of its contour to the marine speaking-trumpet of the Middle Ages.