the connecting bond between it and the
rest of the ancient world,--Egypt, India, and the lands of the
Mediterranean. Owing, however, to the imperfect character of the means
of transportation in ancient and, for that matter, in modern times, the
voyage up the stream was impracticable. The rafts, resting on inflated
bags of goat or sheep skin, can make no headway against the rapid
stream, and so, upon reaching Baghdad or Basra, they are broken up, and
the bags sent back by the shore route to the north.

The contrast presented by the two rivers is paralleled by the traits
distinguishing Upper from Lower Mesopotamia. Shut off to the north and
northeast by the Armenian range, to the northwest by the Taurus, Upper
Mesopotamia retains, for a considerable extent, and especially on the
eastern side, a rugged aspect. The Kurdish mountains run close to the
Tigris' bed for some distance below Mosul, while between the Tigris and
the Euphrates proper, small ranges and promontories stretch as far as
the end of the Taurus chain, well on towards Mosul.

Below Mosul, the region begins to change its character. The mountains
cease, the plain begins, the soil becomes alluvial and through the
regular overflow of the two rivers in the rainy season, develops an
astounding fertility. This overflow begins, in the case of the Tigris,
early in March, reaches its height in May, and ceases about the middle
of June. The overflow of the Euphrates extends from the middle of March
till the beginning of June, but September is reached before the river
resumes its natural state. Not only does the overflow of the Euphrates
thus extend over a longer period, but it oversteps its banks with
greater violence than does the Tigris, so that as far north as the
juncture with the Khabur, and still more so in the south, the country to
both sides is flooded, until it assumes the appearance of a great sea.
Through the violence of these overflows, changes constantly occur in the
course that the river takes, so that places which in ancient times stood
on its banks are to-day removed from the main river-bed. Another
important change in Southern Babylonia is the constant accretion of
soil, due to the deposits from the Persian Gulf.

This increase proceeding on an average of about one mile in fifty years
has brought it about that the two rivers to-day, instead of passing
separately into the Gulf, unite at Korna--some distance still from the
entrance. The contrast of seaso