[ih] Internet-history Digest, Vol 48, Issue 13

[John Shoch]

I'm no expert, but.....:
--Early telegraphy (wired, pre-Marconi) often had operators writing down
messages as they came in, and re-keying them on to the next station.
--This has often been cited in the evolution of digital communications.
--Many years ago Lewis Branscomb (then Chief Scientist at IBM) started a
talk with a description of the first telegraph line built across Australia,
from Adelaide in the South to Darwin in the North (where messages could be
re-sent on an underseas cable to Java, and then on to Europe)
https://en.wikipedia.org/wiki/Australian_Overland_Telegraph_Line
--There were, I think, 11 "stations" built across the route -- with
operators to receive and re-transmit messages.
--Branscomb cited a book about one station built in the outback at Alice
Springs -- "Alice on the Line";  initially set ca. 1900;  I tracked down a
copy and read it.
https://www.barnesandnoble.com/w/alice-on-the-line-doris-blackwell/1026425911
https://openlibrary.org/works/OL26452045W/Alice_on_the_line?edition=key%3A/books/OL8647342M
--The book has great stories about the hardships in getting to and running
a telegraph relay station in the desert.  [Sadly, the book is also a
disturbing reflection of social and racial aspects of this very different
time and place......]

--I also have a set of Boy Scout semaphore flags, which I have used in
talks on digital communication.
--Messages can be forwarded along a string of people.
--It has a 2-of-8 encoding, allowing 28 regular symbols (plus two
sort-of-out-of-band pause and error signals).
--With the 28 regular symbols, it provides a good lesson on the difference
between bit-rate and baud [yes, the purists will remind us that "baud rate"
is redundant, or a first derivative.....]

John Shoch