The lower course of the Danube, in Roumania and Bulgaria, is through a
flat and marshy tract, fertile but badly cultivated and thinly peopled.
It forms the northern boundary of Bulgaria as far as Silistria; and from
here it turns northward, skirting the Dobruja, and flows between marshy
banks to Galatz, receiving on the way the Jalomitza and the Sereth.
From Galatz it flows east, and, after being joined by the Pruth from
the north, it continues southeast to the Black Sea.
The delta is a vast wilderness (one thousand square miles) cut up by
channels and lagoons; the farthest mouths are sixty miles apart.
Two-thirds of the Danube’s volume passes through the Kilia, which, like
the southern or St. George branch, forms a double channel near the
outlet; and so ships enter by the middle or Sulina mouth, deepened to
twenty feet and straightened in 1858-1903. The steel cantilever bridge
across the river at Tchernavoda is one of the great railway bridges of
the world.