Twybil

The appearance of a twybil is that of a T-shaped double-edged axe with unusually long blades and a very short handle.

This appearance is deceptive, as they are actually derived from a large double-ended chisel with a side handle added for better control.

Traditionally these were first cut by drilling with a brace and bit to mark out each end, then the twybil used to break out the wood between them.

[3] Their short handle allows them to be easily flipped end-for-end, making for quick working as each blade is used alternately.

[5] Their name may originate from a root of "twy-" for "two", indicating their double-ended nature, and "-bill", a common description for edged tools (e.g.

The length of the side handle remains roughly constant at around a hand's span and so their proportions change.

A small one intended for making hurdles[8][9] may have three arms of approximately equal length, a large framing twybil may be three feet long and yet still have the same handle.

Diderot's Encyclopédie of the 18th century shows a bisaiguë in use for paring end grain of a large joint, much as a modern slick chisel, which is long enough to rest on the carpenter's shoulder.

[9] Only large, or high-quality work required the square ends and smoothed sides of a precise mortise, trimmed by this variety of chisels.

The apprentice will often use all three mortising tools interchangeably and randomly, making much effort of removing the waste as small chips.

The skilled framer uses each appropriately in turn, working faster, with less effort and not bothering to tear a large block of waste into fragments.