DREITEK wrote:

> About 15 years ago I worked on a machine that used a high voltage high
> current pulse from a large capacitor bank to blow holes in ceramic
> material with a shock wave of water.  This was done using a vacuum
> tube switch.

> Just a thought.  There are still some very good uses for vacuum tubes.

  Vacuum tube?  It wasn«t by chance mercury vapour was it?

  Cheers,
        Paul B.