Brewer's: Killed by Inches

In allusion to divers ways of prolonging capital punishments in olden times; e.g.: (1) The “iron coffin of Lissa.” The prisoner was laid in the coffin, and saw the iron lid creep slowly down with almost imperceptible movement— slowly, silently, but surely; on, on it came with relentless march, till, after lingering days and nights in suspense, the prisoner was at last as slowly crushed by the iron lid pressing on him. (2) The “baiser de la Vierge” of Baden-Baden. The prisoner, blindfolded and fastened to a chain, was lowered by a windlass down a deep shaft from the top of the castle into the very heart of the rock on which it stands. Here he remained till he was conducted to the torture-chamber, and commanded “to kiss” the brazen statute of the “Virgin” which stood at the end of a passage; but immediately he raised his lips to give the kiss, down he fell through a trap-door on a wheel with spikes, which was set in motion by the fall. (3) The “iron cages of Louis XI.” were so contrived that the victims might linger out for years; but whether they sat, stood, or lay down, the position was equally uncomfortable. (4) The “chambre à crucer” was a heavy chest, short, shallow, and lined with sharp stones, in which the sufferer was packed and buried alive. (5) The “bernicles” consisted of a mattress on which the victim was fastened by the neck, while his legs were crushed between two logs of wood, on the uppermost of which the torturer took his seat. This process continued for several days, till the sufferer died with the lingering torment. Many other modes of stretching out the torment of death might easily be added. (See Iron Maiden.)

Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894

Killed by Kindness

Kill Two Birds with One Stone