KnowraOptical telegraphLinked fromLinked fromThe 6 pages that link to Optical telegraph, each with the reason it gives.All 6Broader topic 2Related 1Compared with 3Morse codeCompared with: Optical systems also encoded messages, but used mechanical or visual codes rather than Morse signals.Electrical telegraphCompared with: It sent coded messages before electrical signals could travel through wires.Pavel SchillingCompared with: It was an established alternative to electrical signaling when Schilling built his telegraph.