The image on this card has an unusual property. When holding the card close up, the message reads Merry Christmas. When viewed from a distance it reads Bah! Humbug. It is one of a series of Duillusion Cards from www.pinsharp3d.co.uk.

This is a simple kinetic sculpture. When the red ball which hangs from the thread above is moved sideways and released, as it swings from side to side the image of it in the hemispherical mirror behind moves in the opposite direction. If the red ball swings in and out from the frame, the image of it creates other effects. From Design Marketing, 31 St. Johns Road, Croydon, Surrey, England.

When you look at the surface of this mirror it appears perfectly smooth. However, if you point the mirror towards the sun, and obtain a reflection from it on a piece of paper, an amazingly clear image appears, as illustrated. The mechanism of formation of images like this has been a topic of interest for many years. The collection also contains a printed copy of ‘The Japanese Magic Mirror’ which is the report of a talk and demonstration by Major C.H. Montgomery given before The Magic Circle on 16 May 1949. It was published as a Supplement to ‘The Magic Circular’, July 1949.