The brazen head of Roger Bacon — among others — is one of those recurring widgets in supernatural fiction. It’s a source of prophecy, arcane wisdom and all that fun stuff. Whether or not such a thing existed or had any of the capabilities ascribed to it, the idea of such a thing is enough to inspire any number of mystics to attempt to craft their own.
The particular example pictured to the right is certainly a more modern expression of the concept. With a name like Egocentric Armillary, it puts me in mind of Unknown Armies‘ human-centric universe. Everything in the game world is the product, consequence or fault of humanity. There are no beings from beyond or aliens. It’s all humans and the things they do to each other. In that world, I can see the aluminum skull working as a sort of avatar detector, since avatars and the Invisible Clergy members they emulate are the underpinnings of the current universe. This armillary swivels to stare in the direction of the nearest avatar utilizing one of their channels within a range of three miles, three feet and three inches, while constantly shrieking “You did it! You did it!”
Needless to say, most members of the occult underground tend to pass this one off in trade sooner rather than later, or at least invest in some sturdy foam earplugs.
Thanks to Propnomicon for the link to Egocentric Armillary.