In practical terms the South Pointing Chariot was a simple direction finder. It could have been made to point in any direction - north, south, east or west.

As I was working I noticed that the way I designed the differential gearing actually created a spare drive that sat directly below the emperor's feet, or where they would be if he were to sit in the chariot.

It inspired all sorts of whims and fancies that I ultimately wove into a fairy tale complete with muse, the earth, the moon, some famous inventors, a dog and a rabbit.

The original item looked like a little hand cart with the figure of a man mounted on a platform between the wheels. The man's outstretched arm always pointed south.

In the fairy tale the painting represents the here and now. The book is actually divided into five sections, through which the key character, the muse, leads us.

I started by looking at what others had done before me. You see, over the years there have been attempts by many different people to reconstruct the chariot.

I took lots of photographs and had planned to write a treatise on how it worked, but I quickly got bored with that idea and wrote a scientific fairy tale instead.