Page:Political History of Parthia.pdf/296

250 campaign in Mesopotamia. The latter fought an engagement at Sura (Sūriyyah) above Circesium and then threw a pontoon bridge across the Euphrates in much the same manner as would a modern military engineer. Pontoons were collected back of the lines and brought forward above the point to be bridged. They were then floated downstream one by one and anchored at the desired point. The planks which the boats carried were used to join them to the bank or to similar pontoons farther out in the stream. Protection was given to the engineers by archers from a tower mounted on the pontoon nearest the opposite bank. Once across the river Cassius turned southward along the stream, took Dausara and Nicephorium (Rakka), and then won a bloody engagement near Dura-Europus, which thenceforward