[krilly]

I was just about to ask HN to come up with some communication devices using only ancient technology.

Although your rubber duck system would require less manpower than a system of signal fires, it would be MUCH slower, and probably even slower than the chains of horse riders that delivered messages Pony Express-style across the Roman Empire. In an emergency, a message could be transferred over 100 miles a day.

https://en.wikipedia.org/wiki/Cursus_publicus

[JoeAltmaier]

Oh! And for your ancient-networking subject, I submit:

  * grow trees in rows; cut them in ascii sequences (a stump is a 0). Visible for miles!
  * scratch dated messages in turtles' shells; sample shells continuously and collate
  * spread gossip where the subject is a code e.g. marital infidelity means one thing, sexual preference another. Collect gossip and reconstruct. Use political topics for ack and nack. 
  * Grow crops each year to encode the message: corn is a 1, soybeans a 0. Study crop market reports. Caution: baud rate is low and noise level high, recommend using ECC
  * Become a fashion icon. Adjust skirt lengths microscopically and seasonally to encode multiple bits! A plus: observation and measurement has side benefits

Let me know if any of these suit your purposes. I release them to the public domain.

[rtkwe]

Friendly reminder that the code block style is basically unreadable on mobile (and not so great on desktop either) because it doesn't wordwrap.

[shabble]

Or just implement an appropriate RFC[1] :)

[1] https://tools.ietf.org/html/rfc1217

[ThePadawan]

The ancient Greeks beat this in terms of slow delivery:

"In 499 BC, he shaved the head of his most trusted slave, tattooed a message on his head, and then waited for his hair to grow back. The slave was then sent to Aristagoras, who was instructed to shave the slave's head again and read the message, which told him to revolt against the Persians"

https://en.wikipedia.org/wiki/Histiaeus

[ncmncm]

Need a stable of slaves with different tattoos. Or maybe just two: revolt, or wait for next round. Or put a numbered list on one, and send the next with just a number.

[JoeAltmaier]

I imagine it would be useful for some information. Crop reports etc for helping predict market fluctuations. All aqueducts lead to the city after all! Where the markets are.

Anyway its nearly free, and the infrastructure was always in place. I'm just surprised it didn't get used.

[flir]

Not even sure it's still available online, but you need the dead media project's working notes.

The problem with rubber-duck aqueducts is that they so rarely go where you want to go.