Would it have been possible to build a rudimentary telegraph network in the stone age? Not too long ago, Jamie O'Sheathe of the Office for the Development of Substitute Materials set out to discover just that, venturing into the wilderness to determine whether a working telegraph might be built without the use of modern tools.
Inspiring? Certainly. Green? Don't be fooled:
"I used an estimated 20 kg of charcoal to produce perhaps 20 g of metal. Much of this was wasted in the learning curve, but it was used just the same. This is a fuel to metal ratio of 1000:1. The worst modern metal process I am aware of, the Pidgeon process operating in China to produce magnesium with coal, has a ratio of 25:1, 4000% more efficient than my process. [...] I had zero emissions control. While roasting my copper ores, I directly vented all the gases being produced. The noxious sulphur dioxide, chief precursor to acid rain, gagged me when I got too close. Moreover, I got sick twice after this phase of the process. At first I assumed this was from the sulphur, but after further reading, my symptoms more closely resembled mild arsenic poisoning. Arsenic is a heavy metal usually found in ores of copper that sublimates away during the roasting process. So I have to issue a 'don't try this at home' warning."