The short hand is the minute hand. The long curved hand sweeps out the hours. The current hour is at the position where the curved hand intersects the vertical hour numbers. A sticker on the box says it was designed and made in the UK by Robert Darwen www.ideasintime.co.uk.

This specimen came from Boron, California. It is called TV Rock because, if you place it over an image, the image appears to be at the top of the rock, as on a TV screen. The fibers of Ulexite act as optical fibers, transmitting light along their lengths by internal reflection. Much more detailed information can be found on the web.

It is called TV Selenite because, if you place it over an image, the image appears to be at the top of the rock, as on a TV screen. The fibres of the selenite act as optical fibres, transmitting light along their lengths by internal reflection. Lots of detailed information can be found on the web.

If you enjoy scientific curiosities, it is well worth adding this to your collection. Place the ball bearings and magnet on the green ramp as shown, with one ball bearing at the top of the ramp. As this top ball rolls slowly down the ramp, when it gets close to the strong magnet it is attracted and rapidly speeds up. This happens so close to the magnet that the effect is not visible. However, the ball is now travelling at high speed and, as it impacts the magnet, the ball bearing at the end of the row is shot off at huge speed in a very surprising way.

Produced by Pollock’s Toyshop, in support of the Wilton’s restoration fund, the diorama card is an illustrated peepshow of Wilton’s in the 1850s. With an illustrated backplate on which to write a message, the card folds down flat and comes with an envelope. Bought from Pollock’s toyshop in Covent Garden in 2016.