Inside Out Library · Explore

Triumphs and wonders of the 19th century, a volume of original, historic and descriptive writings showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress (1901)

Boyd, James Penny, 1836-1910 · Philadelphia, A. J. Holman & co · leaf 39

An illustration from Triumphs and wonders of the 19th century, a volume of original, historic and descriptive writings showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress, 1901, leaf 39
-ing of four separate messages over thesame wire, two in one direction andtwo in another. This was followed bythe invention of Grays harmonic sys-tem, by means of which a number of messages greater than four are trans-mitted at the same time over the same wire: and this again by Delaneyssynchronous… … CYRUS \V. FIELD. WONDERS OF ELECTRICITY 29 For a time successful telegraphy was limited to overland spaces, the conduct-ors or wires, consisting of iron or copper, being insulated where they passedthe supporting poles. In the cities, supporting poles proved to be unsightlyand dangerous, and they…

Progress · Inventions

Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.

More pictures from Triumphs and wonders of the 19th century, a volume of original, historic and descriptive writings showing the many and marvellous achievements which distinguish an hundred years of material, intellectual, social and moral progress

More like this