« RSS feeds? | Main | Mickey Mouse and investment in music »
February 6, 2005
19th century networking
From John Steele Gordon's An Empire of Wealth:In the 1830s a man, every business day, would climb to the top of the dome of the Merchant Exchange on Wall Street, where the New York Stock and Exchange Board then held its auctions. There he would signal the opening prices to a man in Jersey City, across the Hudson. That man would signal them in turn to a man at the next steeple or hill, and the prices could reach Philadelphia in about thirty minutes. It was clumsy at best (and, of course, didn't work at all in bad weather).
This system was replaced by telegraph, of course, but from a certain networking perspective, there's not much difference between telegraphy and semaphore flags.
Posted by ekr at February 6, 2005 7:01 PM | Filed under:
Comments
And a version of this semaphore, which communicated one bit of information, dates back to Middle Earth, at least according to Peter Jackson. :-)
Posted by: PG at February 6, 2005 7:36 PM
The Chappe semaphore system of 1793 allowed the nascent French Republic to muster its forces and repel a coalition of pretty much the entire rest of Europe. By the end of Napoleon's empire, the network stretched as far as Amsterdam or Venice. It was reserved for government use, however.
Alexandre Dumas' "The Count of Monte Cristo" has a scene, set in the 1840s, where the count, knowing his enemy uses information gleaned from the telegraph to engage in insider trading, bribes a telegraph operator to issue a false message and ruin the trader.
Posted by: Fazal Majid at February 6, 2005 7:57 PM
Terry Pratchett takes this idea (the semaphore flags, I mean) and runs with it in "The Fifth Elephant", and I believe in "Going Postal", although I'm waiting for the paperback.
Posted by: Andrew McGuinness at February 7, 2005 12:28 PM
You'll want to read "The Early History of Data Networks", by Gerard Holzmann. See http://spinroot.com/gerard/hist.html
Personally, I wish Holzmann had gone more into the protocol(s) used by the optical telegraph systems, but I suppose this book counts more as history than computer science.
Posted by: Bruce Ediger at February 8, 2005 7:48 AM