On Fri, 22 Oct 2010 19:22:41 -0400, "Steve W."
wrote:

Beryl wrote:
Existential Angst wrote:
Awl --
A sodium lamp fixture, 10# or so.

I see two options: screw right into the tree (SS deck screws?), or
big hose clamps (or threaded-rod/plate equiv) around the tree.
Both can impact the tree, it seems. Mebbe a hoseclamp with springs,
for tree growth? That's a pita, tho.

Would be about 20 ft up, on the trunk, not a branch.
I would would proly put the weatherproof box to a long-ish board or
alum strip/bar, and attach that to the tree, for torque issues.

The trunk would be about 10"-12" in diameter at that height. How
deep can one screw into a tree without doing harm?

The ones I put up are lagged in place with 4 stainless lags each. They
are headless lags with machine threads on one end and lag screw on the
other. Drilled a pilot hole and screwed them in about 4" and left about
4" sticking out. To them I mounted a nice piece of stainless plate and
the light was mounted to that. Nice and solid and there is space for the
tree to grow. Now I am just waiting for a new tree to grow out in the
middle of the yard so I can mount a light there... May be a while!

Ah reckon so. Um, why do yo uwant a light in the middle of your yard?
Won't house-mounted spots work?

--
I am an old man, but in many senses a very young man.
And this is what I want you to be, young, young all
your life. -- Pablo Casals