The thumbscrews or pilliwinks is a torture instrument which was first used in medieval Europe. It is a simple vice, sometimes with protruding studs on the interior surfaces. The victim's thumbs or fingers were placed in the vice and slowly crushed. The thumbscrew was also applied to crush prisoners' big toes. The crushing bars were sometimes lined with sharp metal points to puncture the nails and inflict greater pain in the nail beds. Larger, heavier devices based on the same design principle were applied to crush knees and elbows.
As late as the mid-18th Century, the ex-slave Olaudah Equiano, in his autobiography "The Interesting Narrative of the Life of Olaudah Equiano" documented the use of thumbscrews to torture slaves.[1]
During this period (mid-18th Century) Thomas Clarkson carried thumbscrews with him to further his cause for the abolition of the Slave Trade, and later emancipation of slaves in the British Empire. He hoped to and did inspire empathy with the display of this and other torture devices used on slaves.[2]