the.com/plumb bob
a string and a weight that out-argues every architect about which way is down
means A pointed weight hung on a string that, pulled straight down by gravity, shows you a perfectly vertical line.
from The 'plumb' comes from Latin 'plumbum,' meaning lead — the dense metal these weights were traditionally cast from, and the same root that gives us the chemical symbol 'Pb' and the word 'plumber' (originally one who worked with lead pipes). 'Bob' is an old English word for a hanging, swinging weight or pendant, the same sense found in 'bobbing' up and down. So a plumb bob is, quite literally, a 'lead weight that dangles.'
- older than rome
- Egyptians used them building pyramids 4,500 years ago
- name origin
- plumb comes from plumbum, Latin for lead
- never wrong
- points exactly toward Earth's center, always
- surveyor staple
- defined property lines before lasers existed
- gravity powered
- needs no batteries, calibration, or trust issues
foucault's pendulum — 58-meter brass ball suspended in paris panthéon in 1851 to demonstrate earth's rotation
stanley fatmax plumb bob — common construction tool, 16 oz model used by carpenters for vertical alignment