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show me a picture of a plumb line
what are the uses of a plumb line
A plumb bob may be in a container of water, molasses, very viscous oils or other liquids to dampen any swinging movement, functioning as a shock absorber.
how to use in construction a plumb bob
1. Measure two to three few inches away from the top of the wall, and make a mark. 2. Set a nail in the mark. 3. Hang the plumb bob on the nail, letting gravity draw a vertical reference line for you. 4. When the plumb bob is done oscillating, measure the distance from the wall. If it matches the measurement at the top of the wall, your wall is plumb.

Question: what are the alternatives
Self-contained rewrite: what are the alternatives to using a plumb bob