Fuente: WIPO "milk" 222,005. Imray, O. Y., (American Milk Products Corporation). Dec. 4, 1923. Illusion apparatus. - An advertising device which produces the illusion of a disappearing container for milk or other food products consists of an open-fronted casing 10 fitted with a mirror 11 extending from the corner 12 to the middle 13 of the casing, where it abuts against a nickelplated rod 16. Preferably the interior of the casing is lined, e.g. with green blotting paper or cloth, and a diagonal slot 14 is provided in each side wall to disguises the presence of the mirror, so that when lamps 15 are lit an apparently empty interior is revealed. Behind the mirror 11 extends a shaft 17 fitted on the outside of the casing with an enclosed pinion 18, Fig. 3, engaged by a toothed segment 20 actuated at intervals by an arm 24 connected by a rod 25 to mechanism which gives it a reciprocating motion. To the shaft 17 is fixed a sleeve 30 carrying an elbow 32 or an extension 33 of which swings the container 35, the weight of which is balanced by a helical spring on the shaft 17. The container is weighted at 41 and counter-balanced by a spring 38. As the shaft 17 rotates to bring the container 35 from its upper visible position to its lower hidden position, the spring 38 and weight 41 effect a turning motion of the container from its vertical position to a horizontal position in which it can lie behind the mirror. The reverse takes place on the return movement of the container, which is positioned vertically by an abutment 57. A door 50 is pivoted at 52 and connected by a spring 54 and a rod 55 to the mechanism operating the rod 25, the actuation being so timed that on successive openings of the door 50 the container 35 is visible and hidden.