My thoughts are that all you’d need to do is point the “engineers” of the time in the right direction, and they’d probably figure things out better than you could do yourself. Build a small scale model, and leave it up to them to make it work big league.
How would you prevent copper wires to be stolen? Am I mistaken in thinking that copper would have been very valuable at the time?
Early telegraphs worked off battery power. The telgraph operator assembled a new battery every shift. At the end of the shift, the battery was expended and the electrodes were corroded. The power actually came from refining the metal electrodes, so you’d need a steady supply of those.
Your standard galvanic cell uses zinc as anode and copper as cathode. Zinc wasn’t actually recognized as a distinct metal until sometime in the middle ages. (They made brass in the ancient world by smelting copper with zinc ore.) If you need zinc for an electrode, you’d have to teach their smiths how to refine it, which shouldn’t be all that difficult. It wouldn’t be at all beyond their capabilities. Or perhaps you could use some other metal for the anode.
I’d guess the cost of a regular telegraph would be beyond what they could afford back then. Metal was a quite expensive material then and you’d need a lot of it. But the cost of a semaphore system would also probably be too high. Even with telescopes, you’d have to built lots of towers and staff them. The British had a semaphore system during the Napoleanic Wars (different in detail from the continental system, but essentially the same) but they retired it as soon as the wars were over because of costs.
When you catch someone that has done it, you draw out their intestines and symbolically hang them between two poles. While still attached to the thief’s body. While they are still alive. Doesn’t prevent theft, but gives someone pause to weigh the odds.
The Romans were more bold and proactive about dealing with crime than us timid moderns.
Much of this optical and electrical technology is discussed in ‘The Victorian Internet’ - interesting book! (to me, anyhow)
You are correct. Likely the easiest, quickest approach would be building a primitive spark gap transmitter and receiver. The basic materials and technology are very primitive and don’t require fabricating or laying miles of copper wire:
Although it has only been recently understood, the fabrication and material technology existed in that era to perform fine precision work. This is shown by the Antikythera mechanism, which may date to 200 BC. This may pre-date Roman technology and was apparently designed by Greek scientists.Given this level of fabrication and material craftsmanship, fabricating a spark gap transmitter would not be difficult if directed by a knowledgeable visitor from the future.
Reproductions of Antikythera mechanism: http://images.mentalfloss.com/sites/default/files/styles/insert_main_wide_image/public/Antikythera_model_front_panel_Mogi_Vicentini_2007.jpg
https://www-tc.pbs.org/wgbh/nova/assets/img/full-size/ancient-computer-merl.jpg
A spark gap transmitter capable of any useful distance would be near impossible to build. These were not simple desktop devices. For a useful transmission distance the spark needs to run many thousands of volts, and requires non-trivial amounts of power. This usually meant an alternator. Battery power is not viable.
The big problem for any telegraph/semaphore system is the ease with which it could be disabled. The successful optical telegraph systems ran over the territory of the operating country. Mostly being designed to allow messages to be sent from the borders to the capital. They didn’t pass over uncontrolled or potentially hostile lands.
For the Romans they would be sending messages back to Rome across lands that they controlled via invasion, and held with force. These are potentially hostile lands, and the main reason messages needed to be send was to keep control. If you wanted rebellion, the first thing you would do is to disable the telegraph system, by either cutting wires, or taking a semaphore station or two. Of course the lack of communication would probably result in an army being sent from Rome, but lots of guerilla action against stations or wires would be a good way to render the system unreliable and the Romans would tire of sending out an army every time communication was lost. Thus rendering the system less than useful for it prime purpose.
OTOH, for peaceful times, and for commerce and general running of a stable regime, a telegraph or semaphore is not unreasonable. The wikipedia page on Roman metallurgy suggests they produced 15,000 tons of copper a year. Diverting a small portion of that for construction of an empire wide telegraph isn’t insane if the strategic value can be demonstrated. As noted above, the question is the development of wire drawing technology. There is always the adage that knowing something is possible is half the problem of invention. Starting with the knowledge that a successful wire drawing system is possible, it isn’t hard to imagine commissioning the local metalworking artisans into working on a solution. Drilling sapphires with a diamond to create a set of dies isn’t unreasonable. The problem then is scaling production of wire. The Romans understood scaling when they needed it.Again, demonstrating the strategic value to the empire might be able to unlock significant human resources.
An electrical telegraph would be much more susceptible to unexplained communication interruptions than a semaphore telegraph. If a semaphore tower were attacked or destroyed, the people in the next tower would see what had happened and could report it, so the people in command would know whether it was a large army attack, a band of raiders, or a natural event like an earthquake or lightning strike. This is actually a big advantage of a semaphore system – apart from their duties in relaying transmissions between the adjoining towers, having men on site across a large area can give first hand reports of distant events without the need to send people out to investigate.
Well, that’s easy. First, ask the Romans for a potato…
The power source would be the problem. A telegraph is practical for relatively long distances. Your average Roman courier could easily cover 10 miles in an hour, sending a message 50 miles in one day wouldn’t be a problem, so we’re talking at least 50 miles to get a real advantage from the system. It wasn’t like they could exploit a stock trading system by sending messages a little faster, the advantage of a telegraph would be in covering long distances, and that requires heftier power supplies and repeaters in the lines, or AC electricity. Constructing alternators or just generators with commutators isn’t out of the question for the Romans but requires a little more knowledge than something as simple as a telegraph. Some simple relays would help to amplify the signal at the receiver end, also not all that difficult to construct. Making copper wire and the components are all possible, stringing the wires on poles for miles on end is no real problem for the Roman road and aqueduct builders, but justifying the initial cost and maintenance of a long run of wire would be the difficult part.