The “VIOLINO” or “Running drill.”
(explanation courtesy Matt Auvinen)
The drill must be the most ancient of mechanical devices. Wrapping a chord around a long shaft to make it turn was used for making friction to start fires. Attach a hard point on the end of this shaft and you have a tool for drilling holes into wood. Drills of this nature have been found in ancient Egypt.
One can operate this drill alone or with the aid of an assistant. Before the advent of electric drills many artisans got their start in the stone carving workshops pulling the chord for one of these drills.
To operate this alone a “bow” can be used, which is wrapped around the cylindrical “drum” of the instrument. One pulls the bow back and forth, similar to a violin player, and the drill bit cuts going clock-wise and counter clock-wise. For very delicate work the operator can use the palm of her hand to rotate the drum.
The name “running drill” comes from its use to make long grooves in stone (like what we see in classical drapery). The cutting end of the drill bit is held at such an angle that cuts into the stone yet moves ahead.
The advantages of this type of drill are:
1) the bits have a very long shaft and can reach into deep recesses
2) the cutting end of the bits flare out and have a thin “neck” making it possible to drill with undercuts
3) the cutting ends of these drill bits/shafts can be made very small, permitting drill work into small recesses
4) in a typical use, the drill bit does not heat up the stone, and therefore does not compromise the structural integrity of delicate areas of a sculpture
5) one does not need electricity to use this drill
6) one can replicate the drilled effects of the surfaces of sculptures made before electric drills were available.