In 1770 Edmé-Gilles Guyot detailed how to project a magic lantern image on smoke to create a transparent, shimmering image of a hovering ghost. This technique was used in the phantasmagoria shows that became very popular in several parts of Europe between 1790 and the 1830s. Other techniques were developed to produce convincing ghost experiences. The lantern was handheld to move the projection across the screen (which was usually an almost invisible transparent screen behind which the lanternist operated hidden in the dark). A ghost could seem to approach the audience or grow larger by moving the lantern towards the screen, sometimes with the lantern on a trolley on rails, just like a tracking shot in films. Multiple lanterns not only could make ghosts move independently, but were also occasionally used for superimposition in the composition of complicated scenes. By experimenting with superimposition dissolving views were invented and became a separate popular magic lantern show, especially in England in the 1830s and 1840s. Dissolving views typically showed a landscape changing from a winter version to a spring or summer variation by slowly diminishing the light from one version while introducing the aligned projection of the other slide. Another use of dissolving views, projected with a triple lantern, showed a sleeping figure while images of dreams were superimposed above its head and dissolved from one scene to another. This is similar to the use of a dissolve in film.