Tim demonstrates a neat trick with a piece of nitinol wire. Pop it into hot water, and the wire snaps into the shape that spells 'I ♡ U'.

Tim has an alphabetical theme today.

'Background Inversion' appears in the next item. A wooden frame contains the letters 'FILM' in black letters on a white background. A wave of the hands, say the magic word, and now the word 'FILM' is now in white letters on a black background. Just like that.

Tim then demonstrates a neat piece of artwork, where the name Sivy Farhi has been drawn such that the black lines spell Farhi, and the white spaces in between spell the name Sivi. It is one of those things that can take a moment before you see it. Created by Scott Kim.

Next, a puzzle created about 40 years ago by James Dalgety, who is a friend of Tim. Inside the Perspex box is a series of magnets, each of which has a letter on it. The magnets repel each other, and the challenge is to create words, such as EASTER or TERESA. A real challenge!

A cube of wood that has been cut in such a way that you can slide out three pieces, leaving a rather skeletal cube. The three pieces have been cleverly cut, and each is one of Tim's initials, TQR are the three letters. The fact that these all intersect when you slide them back into the cube is really very impressive.

A box of paperclips, with a New York City theme. Some paperclips are in the shape of an 'N', some a 'Y' and some a 'C'.

Then a paper engineering book with an alphabet theme. Every time you open one of the pages, amazing transformations happen. Created by the French artist http://www.marionbataille.com/