a magic lantern before 1827. That year he presented "Scenic Views, showing the various effects of light and shade" with a series of subjects that would become classics in many dissolving view shows, while some had already been subjects in the London Diorama the years before. In 1826 Scottish magician and ventriloquist M. Henry's introduced what he referred to as "Beautiful Dissolvent Scenes", "imperceptibly changing views", "dissolvent views" and "Magic Views" which were created "by Machinery invented by M. Henry". The oldest known use of the term "dissolving views" occurs on playbills for Childe's shows at the Adelphi Theatre in London in 1837. Childe further popularized the dissolving views at the Royal Polytechnic Institution in the early 1840s. Technique and equipment Biunial lanterns, with two projecting optical sets in one apparatus, were produced to more easily project dissolving views. Probably the first biunial lantern, dubbed the "Biscenascope" was made by the optician Mr. Clarke and presented at the Royal Adelaide Gallery in London on December 5, 1840. Later on triple lanterns enabled the addition of more effects, for instance the effect of snow falling while a green landscape dissolves into a snowy winter version. A mechanical device could be fitted on the magic lantern, which locked up a diaphragm on the first slide slowly whilst a diaphragm on a second slide was opened simultaneously. Philip Carpenter's copper-plate printing process, introduced in 1823, may have made it much easier to create duplicate slides with printed outlines that could then be colored differently to create dissolving view slides. However, all early dissolving view slides seem to have been hand-painted. References External links Optical toys