FRAN:So Archimedes was working on a problem that had been set by the king because the king didn't know whether his crown was made of pure gold or not. DOM:So it was at that moment in the bath that ...

a forger paints copies of medieval evangelical portraits in gold leaf onto four pages in the book, presumably in an attempt to increase its value and perhaps unaware of the Archimedes text beneath.

Archimedes then experimented with pieces of silver and gold, comparing the amount of water displaced by them with the amount which overflowed when the crown was submerged in water. As well as ...