Random triples
| Subject | Object |
|---|---|
| gptkb:Bell's_electric_sound_transducer | the late 19th century |
| gptkb:Marconi's_wireless_telegraphy_system | the early 20th century |
| gptkb:Marconi's_wireless_transmission_system | early 20th century |
| gptkb:Watt_steam_engine | late 18th century |