The decay of the Roman Empire, destroyed with its own arms, was the most violent blow received by EUROPE. This decay meant, not only the loss of an important civilization, but also of an important technology upon which the glory of the Roman Empire was built. In the XVII^th century, Blaise Pascal discovered the principle of the communicating vessels, i.e., two or more vessels which communicate with one another, so that a liquid poured into one of these vessels passes into the other, rising at the same level in all the others.

                   It was on the principle of the communicating vessels that the Roman Aqueducts were constructed.

The Period of Archaic Rome