For 10 points, name these improvements on the camera obscura.
John Libbey's book Before the Movies profiles a rival of Thomas Eakins named Joseph Boggs Beale who produced popular works for these devices that were sold by the C. W. Briggs company.  Mathematician Thomas Walgenstein was one of the first people to demonstrate these devices to the public and may have learned about them from Christiaan Huygens.  In 1866, L. S. Beale invented a device called a choreuscope which enhanced the fun of using these devices.  A few years later, C. T. Milligan sold expansion sets for these devices that would "slip" or "dissolve" on themes such as Lincoln's assassination.  Etienne Gaspard Robertson's phantasmagoria improved these devices.  These devices typically consisted of two (*) lenses, with the second reversing the often terrifying image.  They could be powered by artificial light.  For 10 points, name these improvements on the camera obscura.
John Libbey's book Before the Movies profiles a rival of Thomas Eakins named Joseph Boggs Beale who produced popular works for these devices that were sold by the C. W. Briggs company.  
magic lanterns