The Telephone

Recently, Germans conducted some scientific exploration involving their best men. Core drilling samples were taken to a depth of 50 metres, and during these examinations, small pieces of copper were discovered.
After running many arduous tests on these samples, the German government announced that 25,000 years ago, ancient Germans had a nationwide telephone network.
The British government was unimpressed, and conducted their own survey. From samples drilled to a depth of 100 meters, they found small pieces of glass, and announced that 35,000 years ago, the ancient Britons had a nationwide optical-fibre network.
The Irish government felt they had to conduct their own survey, their scientists bored to a depth of 200 meters, but found absolutely nothing.
They concluded that, 55,000 years ago, the ancient Irish already had a thriving cell phone network in place.