The Hyperscope is a viewing device that uses a system of mirrors to increase the apparent distance between your eyes, so that they see as if they were further apart. This allows you to see the world in a different way, more exciting and with more depth. This one was purchased in kit form from Grand Illusions Ltd in 2015. www.grand-illusions.com. Design and concept by Terry Pope www.phantascope.co.uk.

This is a well made wooden example of a well known optical illusion. The wooden construction allows for the two wooden table tops to be interchanged. The table tops are in fact of an identical shape and size. This looks impossible, but swapping them over proves that the table tops are indeed identical, although your brain finds it impossible to believe this. Purchased from Grand Illusions Ltd in 2010. www.grand-illusions.com.

This card has two layers, joined in the centre by a rivet which allows the top card to be rotated on top of the bottom one. The top card is clear plastic with black lines printed on it and the bottom one is white with a heart and coloured lines on it. When the top card is rotated the changing moiré patterns create the effect that the heart is rotating. Miracle Cards, copyright BIZARR/m. schmölz. www.bizarrverlag.com. The company is based in München, Germany.

This card has two layers, joined in the centre by a rivet which allows the top card to be rotated on top of the bottom one. The top card is clear plastic with black lines printed on it and the bottom one is white with black lines on it. When the top card is rotated the changing moiré patterns create the effect of movement. Acid Card, copyright BIZARR/m. schmölz. www.bizarrverlag.com. The company is based in München, Germany.

This two-part greeting card has an inner sleeve and an outer sleeve. To bring the card to life, place your fingers and thumbs at the sides of the card and slide the inner sleeve relative to the outer sleeve. The effect will be that the people start dancing. Copyright Rufus Butler Seder. Product of Eye Think, Inc, Boston MA. U.S. Patent No. 5,901,484.

This two-part greeting card has an inner sleeve and an outer sleeve. To bring the card to life, place your fingers and thumbs at the sides of the card and slide the inner sleeve relative to the outer sleeve. The effect will be that fish swim across the card. Copyright Rufus Butler Seder. Product of Eye Think, Inc, Boston MA. U.S. Patent No. 5,901,484.

A finger ring appears to shrink and expand when slowly rotated. The illusion is strong. Copyright 2002 Rob Stiff. The instructions with the ring have on them www.magicmakersinc.com.

This is an excellent scientific novelty which causes amazement when people see it for the first time, irrespective of whether they are scientifically minded. (The version in the Davenport Collection was made for an American company, hence disk rather than disc.) The base is a slightly concave mirror on which you spin a heavy disk, much like you would spin a coin on its edge. However, unlike a coin, the heavy disk spins for a very long time and, as it slows, the sound it makes changes. There is a real surprise when it stops. There are a number of magnetic pieces with holographic surfaces which can be placed on the flat surface of the disk and which create intriguing light and colour patterns as the disk rotates. According to the box it was invented by Joseph Bendik in the 1980s. Made in Taiwan.