I'm kind of confused about all this discussion involving the use of a
plumb bob, which I think would be impractical in most environments.
It seems to me that there are two considerations at hand:
1. Trying to make the tower straight
2. Trying to make the tower vertical.
An easy guide for first objective can be accomplished by fastening a
string (or rope for better visibility from the ground) to the top and
bottom of the tower (spaced a few inches from the tower) and stretching
it taught. It isn't even necessary to measure the distance from the
tower to the line ... you just stand to the side and look for parallelism.
Making a straight tower vertical would only require the help of a good
level applied to the bottom section.
Why would that not be sufficient?
p.s. It is possible to make the guideline taut as a guitar string by
doubling it and using a lever (piece of wood) to twist the pair.
TowerTalk mailing list