The Shatt-el-Hai, moreover, poured its waters into the Euphrates almost opposite the city, and opened up to it commercial relations with the Upper and Middle Tigris.  And this was not all; whilst some of its boatmen used its canals and rivers as highways, another section made their way to the waters of the Persian Gulf and traded with the ports on its coast.  Eridu, the only city which could have barred their access to the sea, was a town given up to religion, and existed only for its temples and its gods.  It was not long before it fell under the influence of its powerful neighbour, becoming the first port of call for vessels proceeding up the Euphrates.

[Illustration:  115.jpg AN ARAB CROSSING THE TIGRIS IN A “KUFA.”]

     Drawn by Faucher-Gudin, from a sketch by Chesney.

In the time of the Greeks and Romans the Chaldaeans were accustomed to navigate the Tigris either in round flat-bottomed boats, of little draught—­“kufas,” in fact—­or on rafts placed upon inflated skins, exactly similar in appearance and construction to the “keleks” of our own day.  These keleks were as much at home on the sea as upon the river, and they may still be found in the Persian Gulf engaged in the coasting trade.  Doubtless many of these were included among the vessels of Uru mentioned in the texts, but there were also among the latter those long large rowing-boats with curved stem and stern, Egyptian in their appearance, which are to be found roughly incised on some ancient cylinders.  These primitive fleets were not disposed to risk the navigation of the open sea.  They preferred to proceed slowly along the shore, hugging it in all cases, except when it was necessary to reach some group of neighbouring islands; many days of navigation were thus required to make a passage which one of our smallest sail-boats would effect in a few hours, and at the end of their longest voyages they were not very distant from their point of departure.  It would be a great mistake to suppose them capable of sailing round Arabia and of fetching blocks of stone by sea from the Sinaitic Peninsula; such an expedition, which would have been dangerous even for Greek or Roman Galleys, would have been simply impossible for them.  If they ever crossed the Strait of Ormuzd, it was an exceptional thing, their ordinary voyages being confined within the limits of the gulf.  The merchants of Uru were accustomed to visit regularly the island of Dilmun, the land of Magan, the countries of Milukhkha and Gubin; from these places they brought cargoes of diorite for their sculptors, building-timber for their architects, perfumes and metals transported from Yemen by land, and possibly pearls from the Bahrein Islands.  They encountered serious rivalry from the sailors of Dilmun and Magan, whose maritime tribes were then as now accustomed to scour the seas.  The risk was great for those who set out on such expeditions, perhaps never to return, but the profit was considerable.