MAGIC LANTERN. Tho object of this remarkable optical instrument is to obtain an enlarged representation of figures on a screen in a darkened room, by means of the pencils of light issuing from a lamp or candle and passing through a convex lens.
The instrument consists of a lantern gene rally of tin, and of a cubical form, in the intirior of which is the light; and at a per foration in one of the sides is applied a tube, projecting horizontally from it, which carries two glass lenses. A. groove in front of the lantern and parallel to that front receives a rectangular frame containing the glass plates on which are painted, with transparent colours, the objects of which an enlarged view is to be obtained. A remarkable improvement in the manner of employing the magic lantern was first exhibited in London in the year 1802. The lantern itself is similar to but larger than that which serves for more general purposes, and the images are represented on a transpa rent screen, which is stretched in a vertical position across a theatre or an apartment; and, this being made quite dark, the spectators occupy the space in front of the screen, while the apparatus is disposed on the opposite side.
All light is excluded both before and behind the screen, except that which, in proceeding from the lantern, produces the image to be observed ; and, the screen being itself invisible, the spectators can scarcely divest themselves of the idea that they are looking into a dark cavern, in which the objects appear to be gra dually advancing towards or receding from them. The allusions produced have caused the name of Phantasmagoria to be applied to the apparatus.
The magic lantern and the phantasmagoria are used only for purposes of amusement ; whereas the CAMERA Onscuma has been made available in photography.