The frequency produced by the string could be 437 Hz or it could be 443 Hz.
The frequency of the beats ... 3 Hz ... tells the piano tuner that
the difference between the fork and string frequencies is 3 Hz,
but it doesn't tell her which one is higher or lower.
recoils and must be tethered or he's gone.
Use of lubricant
Use of ball bearers
Use of streamlined body
Use of graphite
