Witch Pricker

Witch Pricker: interactive installation with code, wool, petticoats, electronics. 2013


Witch Pricker is an interactive installation artwork that investigates the performativity of code through historic subject matter, sculptural object and programmatic interface for visitor participation.


Witch Pricker emerged from researching histories of witch persecution that occurred in Newcastle upon Tyne, UK. The piece was based upon a story from 1649 when a group of local residents were brought forward to be put on trial as witches. The accused were examined by an outside expert, a Scottish witch pricker, who was allowed special privileges to enter Newcastle and perform this duty. Because he was paid twenty shillings per witch he discovered, there was a financial incentive to “find” as many guilty persons as possible (“find” could be read as “create” or “code”, as the witch pricker was actively coding, or programming, the people as witches in the court of public opinion as well as in a legal court). If a person bled when pricked, she was deemed human (and therefore not a witch). If she did not bleed, she was a witch (and therefore guilty). Through this testing process, fifteen people were found guilty of witchcraft and put to death on Newcastle’s Town Moor.


The following pseudo code represents this story:

If (bleeds when pricked) {








else if (does not bleed when pricked) {








In the Witch Pricker installation, a series of hand-felted wool strawberries, draped with skirts, extend from a wall. A push-button switch, a large sewing needle, and a receipt printer sit upon a central plinth. Gallery visitors are beckoned by a commanding voice emanating from this plinth. When one steps forward and presses the button, an audio file instructs him to, “Use the pin to prick each strawberry under her petticoat.” This triggers an invisible randomisation within the program of each strawberry’s guilt or innocence. As the participant pricks each strawberry, a shriek is emitted if the accused (i.e. the pricked strawberry) is “innocent”, and a crowd gasps if a “witch” has been found. Meanwhile, the commanding voice resolutely proclaims each verdict as either, “She’s not a witch” or, “You have found a witch”.


The number of “witches” found is tallied by the artist-written code. As the code randomises the strawberries’ guilt or innocence before each running, the number of witches found ranges from 0 to 5. After his time is up, the participant receives a printed receipt indicating the result of his actions. The participant can take the receipt to a gallery attendant to redeem it for his own incentive; a chocolate coin for each witch found.


The felted strawberries in Witch Pricker are an acknowledgment of 17th century Newcastle where wool was a major industry for trade and strawberries were commonly eaten. The fruit are a metaphor for the vulnerability of those accused of witchcraft. Echoing the random nature of the witch pricker’s verdicts, James Essinger, in Jacquard’s Web, states that a tabulation machine (an early computer) was “...like a magical loom weaving chaotic information into systematic, coherent, and logical patterns.” The textile elements of this installation, including the woven fabric of the strawberries’ petticoats, are inspired by this development of computing from weaving technologies as they originated in the physical object of a punched card.