object
Plumb rule
A named straightedged board with a plumb bob or vial for testing vertical. Not published plumb-bob alone, not a spirit-level, and not a chorobates.
Also known as Plumb board · Mason's plumb rule
object
A named straightedged board with a plumb bob or vial for testing vertical. Not published plumb-bob alone, not a spirit-level, and not a chorobates.
Also known as Plumb board · Mason's plumb rule