Stewart Robert Hinsley wrote:

In article , Archimedes Plutonium
writes
England had hickory species

There were no hickories (Carya) in England during historical times until
they were introduced from America. There are no Carya species native to
Europe (1 native to China, 1 to Tonkin, the remainder to North America)
so it's likely that hickories have been absent from England for a long
time. Googling finds sites that report that Carya has been extinct in
Europe for 2 million years.
--
Stewart Robert Hinsley

I had a mind glitch when I wrote that. I was thinking at that moment that
Butternut was a Carya species and that England has butternuts. But I was
totally mistaken.

Anyway getting back to the issue of test of strength of woods, the white
ash I have is heavier and denser than the hickory and both are reported to
be stronger than oak. So England had no hickories for trebuchets but they
surely had ash trees. Whether they had both White and Green Ash, I do not
know. But if Ash is nearly equivalent to hickory in terms of strength, then
why did they build the trebuchets out of oak when ash was available?

My guess is that oak is superior to various tests of strength and that
strength relies on various dimensions and tests. For example, the test of
placing boards of white oak, white ash and hickory of equal length width
and depth and adding weights to the end of the board until the board snaps.
I would guess oak outlasts the hickory and whiteash. Then there is the
projectile test of which is least impervious to a projectile. Then there is
the durability test for it seems as though oak lasts longer as a flooring
then does hickory which seems to peel off in long splinters.

Archimedes Plutonium
www.iw.net/~a_plutonium
whole entire Universe is just one big atom where dots
of the electron-dot-cloud are galaxies