“Benjamin Rackstrow, a most enterprising showman in Georgian London, staged ‘The Chair of Beatification’, which involved irradiating a willing member of the public with the kind of flaming amazement that Ariel conjured on the shipwreck: ‘a Glass Crown being placed on the Head of the Person who sits in the Chair, immediately becomes filled with Aetherial Fire; and likewise a Glass Sceptre, wherein is to be seen one continued stream of Electrical Fire, of a beautiful Purple Colour’.”

Marina Warner, Phantasmagoria : Spirit Visions, Metaphors, And Media Into The Twenty-First Century (2006)