ATM Hardwood vs. Softwoods

["Richard Andersen" <RichardA@island.net>]

On  Tue, 25 Apr 2000  "Jan van Gastel" <jhm.van.gastel@mdw.vu.nl> 
wrote:

(snip)

> .......................................BTW: (baltic) birch is not hardwood. On
> a 10 points scale from softest to hardest, birch gets a 6 (and soft pinewood
> a 2 or 3), the man in the shop where I bought the baltic birch told me..

(snip)

The terms 'hardwood' and 'softwood' have different meaning in the 
world of lumber dealers. On the main so called hardwoods are harder 
than softwoods but the real determining factor, as far as the trade 
is concerned, is the type of tree that is the source of the wood.

Botanically speaking, softwoods come from Gymnosperms. This group 
includes pines, spruces, junipers, etc. The source of hardwoods is 
the Angiosperm group; trees with broad leaves, seeds enclosed in 
fruit, and that are usually deciduous. An odd result of this 
definition is that Balsa comes out as a hard wood. 

The use of the 'hard wood' term requires some interpretation. In 
general, softwoods come from 'conifer like' trees and 'hardwoods' 
come from 'leaved' trees. There are some small exceptions to this 
definition but it will work for our purposes.

That said, Birch is a relatively hard wood and would be suitable for 
the proposed telescope mount. So would the others proposed. Of that 
group, only fir is a so called softwood.


Richard Andersen
Victoria, B.C., Canada