It is probable that Godwin was referring to Louis Jacques Mandé Daguerre’s diorama depicting the Ruins of Holyrood Chapel. Daguerre’s diorama was characterized by mechanical devices that activated screens illuminated by daylight in order to produce mimetic effects by changing the intensity and colour of the light source. The diorama also relied on shifts in aperture achieved by a rotating viewing room.

See Richard Altick, The Shows of London (Cambridge, Mass: Belknap Press, 1978) and The Times, 21 March 1825.