That city, like Ravenna, originally stood in the midst of a lagoon; and the coast east of it to near Monfalcone, where it meets the mountains, is occupied by similar expanses of water, which are, however, becoming gradually converted into dry land.
The area of the dry land was taken as 28.3% of the surface of the globe, and that of the oceans as 71.7%.
The forms of the dry land are of infinite variety, and have been studied in great detail.'
The greater part of western Asia, including the basin of the Obi, the drainage area of the Aral Sea, together with Afghanistan, Baluchistan, Persia and Arabia, was covered by the sea during the later stages of the Cretaceous period; but a considerable part 3f this region was probably dry land in Jurassic times.
At the same time a portion of the port was set apart as a free harbour, altogether an area of 750 acres of water and 1750 acres of dry land.