"Tim W" wrote in message
...
If you are watching the american president on the telly delivering a
speech in Westminster Hall take a look if you can at the roof. It is one
of the great medieval roofs, a carved oak hammerbeam structure spanning
70ft.

It's suprisingly difficult to find a good picture of it for you. If I find
one I will post it, but the Hammerbeam structure is used where no single
timber is long enough to span the roof, and there are no intermediate
arcades and columns. It was designed and constructed without engineering
and calculation, but by the craft tradition, experience and experiment.

Tim w



There is a worthwhile bit of a book on Japanese monumental
architecture somewhat appropriate here.
A particular historical Imperial edifice
sustained fatal fire damage in the a few dacades ago.

The species of slow-growth wood in the
size appropriate for the lost beams was commercially unknown,
posing a significant dilemma for restorationists; until. When
they looked up at an nearby part of the estate, they discovered the
builders, centuries past, had the foresight to plant trees of the
species which were by then more than sufficient to supply the
timbers needed. That is planning and perspective.

Regards,

Edward Hennessey