From "The Count of Monte Christo":
It was the first time Franz had ever
seen a guillotine, -- we say guillotine, because the Roman
mandaia is formed on almost the same model as the French
instrument.* The knife, which is shaped like a crescent,
that cuts with the convex side, falls from a less height,
and that is all the difference.

A footnote to the text says Dr. Guillotine got his idea from the Roman device.