The Arabian peninsula is a repetition of Africa on a smaller scale and in more moderate proportions, without a river-valley like that of the Nile. The centre is occupied by a table-land, which presents a few well-watered depressions lying under a burning sky between naked deserts, plains of sand, cliffs, and bald peaks. Thus, in spite of the great extent of the country (more than 1,000,000 square miles), there are few districts in the interior of Arabia suitable for agriculture. But towards the south, on the Indian Ocean, the plateau sinks down to the sea in broad mountain terraces. Here are extremely fertile valleys, and the most valuable fruits grow on the terraces in the tropic atmosphere, which is cooled by the elevation of the mountains and the winds blowing from the ocean. This is the land of frankincense, of the sugarcane and coffee-tree, of pomegranates, figs, and dates, of wheat and maize. Herodotus, who follows all antiquity in extending the name Arabia to the deserts of Syria and Sinai, gives us but few notices of the inhabitants of this wide district. "The Arabs," he tells us, "wear long garments, and on the right side carry large bows, which can be strung on either side, and travel on swift camels. They have only two gods--Dionysus, whom they call Urotal; and Urania, whom they call Alilat. Urania is known to the Babylonians as Mylitta, to the Arabs as Alilat. Bargains are struck in the following manner. A third person makes an incision in the hand near the thumb of each of the two persons who wish to enter into the compact, and with the blood he smears seven stones lying between them; calling at the same time on Urotal and Alilat. These compacts are observed with a sanctity unknown to any other nation."[428] Eratosthenes tells us that the Arab tribes lying next to the Syrians and Jews were agricultural, but beyond them lay a sandy and poor soil, with nothing but a few palms, acacias, tamarisks, and wells of water. This district, as far as the Euphrates, was inhabited by the Nabatæans, Agræans, and Chaulotæans, tribes who kept camels and lived in tents.[429] Artemidorus of Ephesus calls Arabia rich in cattle, lions, panthers, wolves, wild asses, and camels; the inhabitants were wandering herdmen, who gained a subsistence from their camels; on them they rode, from them they fought, and on their milk and flesh they lived. The names of the Arabian tribes he is unwilling to mention, because of their insignificance and harsh sound.[430] Diodorus also tells us that the inhabitants of the part of Arabia towards Syria lived by agriculture and trade, but with the Nabatæans the land began to be arid and barren; and they led the life of robbers, plundering their neighbours far and wide; no one had succeeded in conquering them.[431] The interior of Arabia, and the western side, were occupied by plains of sand of enormous extent. On these it was only possible to travel as on the sea, by taking the Great Bear as a guide.