Excerpt from The European Witch-Craze of the Sixteenth and Seventeenth Centuries H.R. Trevor-Roper (1967) Penguin Books, London. Review. page 46.
Of the tortures used, we have plenty of evidence. Basically they were the same throughout the lands of Roman law.
There were the gresilons (in Scottish pennywinkis), which crushed the tips of fingers and toes in a vice; the echelle or 'ladder', a kind of rack which violently stretched the body; and the tortillon which squeezed its tender parts at the same time. There was the strappado or estrapade, a pulley which jerked the body violently in mid-air. there was the leg screw or Spanish boot, much used in Germany and Scotland, which squeezed the calf and broke the shin-bone in pieces — 'the most severe and cruel pain in the world', as a Scotsman called it — and the 'lift' which hoisted the arms fiercely behind the back; and there was the 'ram' or 'witch-chair', a seat of spikes, heated from below. There was also the 'Bed of Nails', which was very effective for a time in Styria.
In Scotland one might also be grilled on the caschielawis, and have one's finger-nails pulled off with the turkas or pincers; or needles might be driven up to their heads in the quick. But in the long run perhaps nothing was so effective as the tormentum insomniae, the torture of artificial sleeplessness which has been revived in our day. Even those who were stout enough to resist the estrapade would yield to a resolute application of this slower but more certain form of torture, and confess themselves to be witches.
Once a witch had confessed, the next stage was to secure from her, again under torture, a list of all those of her neighbors whom she had recognized at the witches' sabbat. Thus a new set of indicia was supplied, clerical science was confirmed, and a fresh set of trials and tortures would begin.