In translated articles we talked about in another part of this listserv, the German engineering professor Lothar Wessolly makes great claims for the ability of the "Elastometer."
He says ("Measurements with Tension Test") the Elastometer can do the following without causing injury to the tree:

1) find the weakest place in the tree
2) determine the size of the weakest place relative to the adjacent cross-sections
3) determine that the residual carrying capacity of a hollow as opposed to a solid part of the tree
4) determine the wind load at which the tree will break
5) quantitatively use tree statics to predict fracture safety
6) non-destructively monitor exactly the same place some years later
7) asses subsequently released or pruned trees with the same validity as free-grown solitary trees

Does anyone know anything about this wonder?

Reply to post by Jerry Bond, on April 14, 2000 at 10:45:01:

Jim Clark mentioned to me that he has an Italian colleague who had Wessoly come down to Italy to do some Elastometer testing... but we didn't get further into it.

In the translations I've seen there is also discussion (regarding windthrow or 'tipping') of an Inclinometer... you place it on the tree or adjoining soil and put the tree under tension. The tension to defect the root system (root plate?) 0.30 degrees (which is non destructive) can be plotted out the the tension (or load) that will cause deflection >2.5-3.0 degrees which is the irretrievable failure deflection. Neither the Inclinometer or the tensioning/measuring device are described. Nor is the method of determining whether the tree will be exposed to failure load (which seems to be described as "hurricane" load).

It may be unfair from the translation (of unknow origin or quality) of one article... but I get the sense you have to go take classes from the author to learn the rest.

Scott