o readily transported, and indeed could
only be conveyed across deep rivers by means of bridges, rafts, or
boats. On the great streams of the Tigris and Euphrates, with their
enormous spring floods, no bridge, in the ordinary sense of the word, is
possible. Bridges of boats are still the only ones that exist on either
river below the point at which they issue from the gorges of the
mountains. And these would be comparatively late inventions, long
subsequent to the employment of single ferry boats. Probably the
earliest contrivance for transporting the chariots, the stores, and the
engines across a river was a raft, composed hastily of the trees and
bushes growing in the neighborhood of the stream, and rendered capable
of sustaining a considerable weight by the attachment to it of a number
of inflated skins. A representation of such a raft, taken from a slab of
Sennacherib, has been already given. Rafts of this kind are still
largely employed in the navigation of the Mesopotamian streams, and,
being extremely simple in their construction, may reasonably be supposed
to have been employed by the Assyrians from the very foundation of their
empire.

To these rafts would naturally have succeeded boats of one kind or
another. As early as the time of Tiglath-Pileser I. (ab. B.C. 1120) we
find a mention of boats as employed in the passage of the Euphrates.
These would probably be of the kind described by Herodotus, and
represented on one of the most ancient bas-reliefs--round structures
like the Welsh coracles, made of wickerwork and covered with skins,
smeared over with a coating of bitumen. Boats of this construction were
made of a considerable size. The one represented contains a chariot, and
is navigated by two men. [PLATE CXXXIII., Fig. 1.] In the later
sculptures the number of navigators is raised to four, and the boats
carry a heavy load of stone or other material. The mode of propulsion is
curious and very unusual. The rowers sit at the stem and stern, facing
each other, and while those at the stem pull, those at the stern must
have pushed, as Herodotus tells us that they did. The make of the oars
is also singular. In the earliest sculptures they are short poles,
terminating in a head, shaped like a small axe or hammer; in the later,
below this axe-like appendage, they have a sort of curved blade, which
is, however, not solid, but perforated, so as to form a mere framework,
which seems to require filling up. [PLATE CXXXI