The workable Exchange (1 янв 1878 г. – 31 дек 1878 г.)
Описание:
The workable exchange was developed, which enabled calls to be switched between subscribers rather than having direct lines.Добавлено на ленту времени:
Дата:
1 янв 1878 г.
31 дек 1878 г.
~ 12 months