With a signal transmitter and a receiver, letters visible at a distance. DataInventory Number: ELE31Date: 1880 (c.)Dimensions: Length: 30cm, Height: 24cm, Width: 20cm (each device)Instrument Categories: Telecommunication PlacesLocation: Ιωνίδειος Σχολή - Ionideios School, PiraeusOrigin: Ιωνίδειος Σχολή - Ionideios School, Piraeus
