  The paper discusses the tale that we can find in "The Architecture" by
Vitruvius, on a method used by Archimedes to determine the percentage of gold
and silver in a crown. The method is based on the immersion of bodies, allowing
the evaluation of their volume in the case of irregular shapes. The
measurement, as reported in "The Architecture", seems to be difficult to
realize. But, using a vessel for a water-clock, the approach that Vitruvius
described is possible. Here the discussion and experiments.
