Telegraph
Long-distance transmission of textual information as a series of on-off electrical signals, using coded pulses like Morse code.
Core metadata
- ID: telegraph
- Era: Industrial
- First known date: 1837 (decade)
- Region: United States and Europe
- Review status: source_checked
- Maturity: established
Prerequisites
- Copper Wiring Production (copper_wiring_production)
- Electricity (electricity)
- Early Electromagnetism (electromagnetism_early_discoveries)
- Writing (writing)
Dependents
- Electric Railway Signaling (electric_railway_signaling)
- Mass Media (Newspapers) (mass_media_newspapers)
- Defense Staff Colleges (military_staff_colleges)
- Phonograph (phonograph)
- Radio Telegraphy (Wireless Communication) (radio_telegraphy_wireless_communication)
- Standard Time Zones (standard_time_zones)
- Modern Stock Exchange (stock_exchange_modern)
- Stock Ticker Systems (stock_ticker_systems)
- Telegraph Cables (Transoceanic) (telegraph_cables_transoceanic)
- Telegraph News Tickers (telegraph_news_tickers)
- Telephone (telephone)
Fields
Field lanes
- Telecommunications & Networking: Foundations & Switching
Node sources
- Invention of the Telegraph (Library of Congress, 2026, official_agency) • Supports: node, maturity
Prerequisite edge evidence
Edge/source evidence summary:
- Prerequisite edges: 4
- Average edge confidence: 72%
- Prerequisite sources: 4
- expert_inference: 4
| Prerequisite | Type | Confidence | Evidence level | Note | Sources |
|---|---|---|---|---|---|
| Electricity (electricity) | enabling | 68% | expert_inference | Electricity provides a capability that enables this technology without being the only possible path. |
|
| Writing (writing) | historical_predecessor | 75% | expert_inference | Writing is an earlier historical predecessor or foundation, not a one-to-one engineering dependency. |
|
| Early Electromagnetism (electromagnetism_early_discoveries) | historical_predecessor | 75% | expert_inference | Early Electromagnetism is an earlier historical predecessor or foundation, not a one-to-one engineering dependency. |
|
| Copper Wiring Production (copper_wiring_production) | enabling | 68% | expert_inference | Copper Wiring Production provides a capability that enables this technology without being the only possible path. |
|
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