time-ball

• Sustantivo que designa una gran esfera que se desliza hacia abajo por un mástil vertical a una hora determinada; históricamente se usaba en observatorios para transmitir la hora exacta a los barcos y al público.

A noun referring to a large ball that slides down a vertical staff at a predetermined time, historically used at observatories to signal the exact time to ships and the public.

1. Time signal deviceC1formal

   A large ball that slides down a vertical pole at a predetermined time, historically used to signal the exact time, especially at observatories or ports.

   Bola de señalización horaria

   • The time-ball at the Royal Observatory in Greenwich drops at 1 PM daily.
   • Sailors used to rely on the time-ball to set their marine chronometers.
   • The time-ball mechanism was an early method of public timekeeping.