The type of early communications that is thought to be between 10,000 - 12,000 years old and can be fond worldwide is : PetroGlyph
It was some sort of carving on the Rocks that ancient people used to communicate before the age of literature
hope this helps
The fastest way to communicate across continents in the 1500s was by ship. If you wanted to bring a certain message across a continent than there was no faster way than actually sending it on a ship and waiting for the ship to arrive safely to the other continent.
Decennial census of population and housing.
