The invention and dissemination of magic lantern technology in the seventeenth century provides a more specific example. The enlarged and colourful images that emanated from the lanterns interior objective lens, projected pictures that were sometimes animated, directly into the exterior world.1 The images had a transparency to them, but also appeared to physically inhabit the projection screen. They were both real and unreal in a way that was bewildering to many spectators of the period; “the shadowy projections on the wall resembled dreams, visions or apparitions summoned up by a necromancer” playing to the popular perception that demons could “imprint and shape subtle matter”2 - the "devil was widely regarded as the master of such delusions”3 (Figure 3)



Treister engages with these pre-enlightenment notions regarding technological occult phenomena, most especially in focusing on the career  of Dr John Dee.  Through a section of Hexen we are presented with Intervention: A collection of artefacts, images and texts relating to the work that Dee carried out as an alchemist, mathematician, and philosopher during the sixteenth century (figure 4).1  Presented within the confines of the Science Museum (London)  an investigation of Intervention shows that Tresiter in not simply interested in notions of (science fiction style) contemporary technological paranoia. Rather, she places a strong focus on the original historical context of the information that she gathers.



For example, although to contemporary audiences, the occult and science would not generally be viewed as a logical pairing, to John Dee and his contemporaries there were no distinct boundaries between these seemingly disparate fields: It was not uncommon to be “engaged in an assortment of intellectual activities that escape the confines imposed by modern disciplinary boundaries and the established canon boundaries of scientific discourse".1  As such, it is possible to define figures such as Dee as a form of early scientist, working before the emergence of the sciences as understood in contemporary terms. 2 It therefore seems an appropriate acknowledgement of this shared history to display Intervention within the Science Museum.



A second example can be identified in the use of Dr John Dee's divination equipment. Central to Intervention is Treister's inclusion of a small drawing depicting Dee's scrying crystal; a polished crystal “showstone”  (or lens) in which Dee sought communion with the divine.1  Treister claims that the crystal's “activities link to aspects of both recent and current military operational programmes” (figure 5).2 Although this statement clearly links to contemporary technological paranoia of futuristic mind-alteration devices, put into a historical context, the idea that this sixteenth century lens could be directly involved in futuristic military events is actually highly appropriate. During the sixteenth century there was a widespread view that scrying instruments were imbued with prophetic qualities. It was believed that crystals and polished lenses could provide a kind of “eye”, capable of seeing into, or revealing “facts” about the future - Dee's crystal was used to foretell the future and predict the oncoming apocalypse.3  The crystals historical context can also be seen as related to claims that it might hold influence over “current military” programmes. In his philosophical capacity, Dee wrote extensively on the topic of imperialist (militaristic) expansion in which he “foreshadowed an empire that would be ecumenical, apocalyptic, territorial, and absolute.”4