Dave Hinz wrote:
On Fri, 29 Jul 2005 02:03:40 GMT, Doug Miller wrote:

Not so far-fetched as it might seem, either: somewhere around 400 AD, the
ancient Romans developed a concrete that would harden under water; when Rome
fell, the secret of making it was lost. Care to guess when it was
rediscovered? Not until 1789. And to this day, nobody knows for sure just
*what* Greek fire really was.

Concrete had been around for hundreds, if not thousands of years
before the Romans. The Greeks had concrete. The Romans improved
on earlier formulations when they found that concrete made with
volcanic soil from Puozzoli hardend much faster than previous
versions. The Greek concrete could take years to cure. Nowadays,
materials added into concrete to make it harden fast are called
possolins.


That is a fascinating tidbit, isn't it? Was the description accurate,
and if so, why can't we reverse-engineer it? We know what materials
they had access to, after all. Maybe it's actions were overstated.


There are pleny of ways to make something that behaves as
described, the only real problem is figuring out how the
Byzantines actually did it using materials they were known
to have, which one presumes did not include reduced sodium
metal.

--

FF