Great facts : a popular history and description of the most remarkable inventions during the present century (1860)
Bakewell, Frederick C. (Frederick Collier), 1800-1869 · New York, D. Appleton and company · leaf 157
ery slow process. It is questionable,indeed, whether that telegraph could have beenworked at all through a circuit of many miles. Mr. Davys telegraph was similar to that of Mr.Alexanders, though much more compact and betterarranged. The letters were painted on ground glass,lighted behind, so that… … telegraph, took out his first patent in 1837. Itclosely resembled in general features the telegraphof Baron de Schilling. It consisted of five magneticneedles, ranged side by side on a horizontal line thatformed the diameter of a rhomb. The needles weresuspended perpendicularly, being kept in that…
Inventions
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