calipers wanted

[Dennis D. McKenney]

I am looking for calipers capable of measuring to 30 to 36" in diameter.
sliding arm on straigth scale is ok but I am trying to find a set that
is shaped like a fan or the letter 'C' similar to those shown in
forestry catalogs for measuring small trees to 8 inches.  This latter
style used to be manufactured but I can't seem to find them now.

Thanks, ddm

e-mail: d_mckenney at conknet.com