Several important watch inventions - George Graham invented mercurial compensation pendulum and dead-beat escapement for clocks, John Harrison invented grid-iron compensation pendulum and George Graham invented the cylinder escapement. (1 янв 1720 г. – 1 янв 1750 г.)
Добавлено на ленту времени:
Дата:
1 янв 1720 г.
1 янв 1750 г.
~ 30 years