A traditional bow-driven stone drill in which a cord wrapped around the drill shaft is moved back and forth with a bow, rotating the cutting point.
Trapano a violino, literally “violin drill,” is a traditional stone-boring tool. A cutting point is mounted in a shaft; a cord wrapped around the shaft is attached to a bow. Moving the bow back and forth reverses the rotation of the shaft while pressure is applied through the handle.
Etymology
Italian: trapano, “drill,” + a violino, “violin-style,” referring to the bowing motion.
Sculptor Notes
The tool converts reciprocating hand movement into rapid alternating rotation. It is particularly useful historically for holes, deep recesses, and passages difficult to create efficiently with ordinary chisels.
References
https://levocidelmarmo.sns.it/scheda_oggetti_relazione.php?denom=trapano+a+violino&id=3