The Nabateans had originally been content with pastoral pursuits. For a time they became pirates and had little skiffs, with which they despoiled all other merchants who trafficked in their seas. Their obvious intention was to protect the trade along their overland route which assumed great proportions as we learn from the remarks of Strabo. One reason of their success in this direction was their extensive use of the camel as a means of transport. There are many references in the Assyrian annals to the large number of camels which were bred in Arabia. Ashurbanipal (B.C. 668-626) says that after his conquest of Arabia, “camels like sheep I distributed and caused to overflow to the people of Assyria dwelling in my country. A camel for half a shekel, in half shekels of silver, they were valued for at the gate.”[128] The Nabateans employed camels in such numbers that Strabo spoke of their convoys of camels (καμηλέμποροι), which moved between Petra and Leukokome in the land of Nabat, with so many people and camels that they resembled armies. The camels moved to and fro at certain periods of the year, being timed by the arrival at Leukokome of the boats from the East. In between they were driven to pasture in the fruitful wadis which lay near the caravan routes. It was to the men herding these camels that the wadis of southern Sinai owed their inscriptions. These inscriptions consist, for the most part, of a few words, including a name or a greeting, which are roughly incised on rock or boulder at about the height of a man above the valley floor. Some are accompanied by signs or by the rough drawing of animals or men, sometimes there are drawings and signs without writing. The animals are chiefly camels, gazelles or cattle. There are some horsemen and some nondescript animals. Among the signs that are used are the Egyptian _ankh_, the Greek _alpha_ and _omega_, and the Christian cross, showing that a great variety of persons passed there. The words are written without regularity, the animals and men are drawn with poor skill. They are, for the most part, unattractive scrawls, the interest of which lies in the information which they indirectly convey. The inscriptions in the wadis of southern Sinai were first noted by the lady Etheria who visited the peninsula about the year 450. A century later they attracted the attention of Cosmas, whose second name, Indicopleustes, marked the extent of his travels. Cosmas was in Sinai about the year 545, and in his _Christian Topography_ wrote of the inscriptions, which he attributed to Israelite industry.