a pivoted axle or shaft on which the balance is mounted.
What’s Nuclear About A Football?Whose nuclear launch button is bigger? There has been a serious kerfuffle in the news about buttons and their relative size. Specifically, nuclear launch buttons. Kim Jong-un, the leader of North Korea, flatly stated that a nuclear button is on his desk at all times. “It’s not a mere threat but a reality that I have a nuclear button on the desk in my office.” …
Origin of balance staff
First recorded in 1880–85
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for balance staff
The roller being fastened to the balance-staff, of course, turns just as the balance turns and with it the jewel-pin.Time Telling through the Ages|Harry Chase Brearley