In the winter of 1905-1906 Petrie, excavating at Tell el-Ye-hudiyeh,[4] about 20 miles north of Cairo, discovered what he believes to have been one of the original encampments of the Hyksos in Egypt. This encampment consisted of a large space, averaging about 1,500 feet in each direction, surrounded by a wall of sloping sand and mud. This wall, varying from 80 to 140 feet wide at the top and from 130 to 200 feet wide at the bottom, presented on the outer side a long slope, and is quite unlike any structure of the native Egyptians. From the nature of the wall and the small objects found near it, Petrie infers that it was the rampart of a people who defended themselves with bows and arrows. A cemetery of the same level yielded to the explorer a considerable amount of black pottery, not at all like pottery of native Egyptian manufacture, and a number of crude scarabs. These objects Petrie believes are products of the art of the Hyksos before they had been in Egypt long enough to adopt Egyptian civilization. In 1912 Petrie discovered a similar Hyksos camp at the site of Heliopolis, the Biblical On. It has been held by many that Abraham, Joseph, and Jacob all went to Egypt during the reign of the Hyksos dynasty. It would be natural for Semites to enter such a country, if it were ruled by a dynasty of the same blood as themselves. Egypt has, however, furnished no positive archæological evidence of this view. The Semitic names just alluded to, which are sometimes cited as evidence of it, in reality only prove that many Semites came with the Hyksos. They make it probable, indeed, that some of the Hyksos were Semites, but give us no positive evidence concerning the patriarchs. On the other hand, nothing has been discovered in Egypt to disprove this view. (3) _The El-Amarna Letters._--In the winter of 1887-1888 a native Egyptian woman, according to one account, accidentally discovered some clay tablets in the soil at Tell el-Amarna, about 200 miles south of Cairo on the east bank of the Nile. She is said to have sold her rights in the discovery for about 50 cents. It was thus that nearly four hundred clay tablets, inscribed in the Babylonian language and characters, which opened an entirely unknown vista in the history of Palestine and the surrounding countries, were found. These were letters written to Kings Amenophis III and Amenophis IV, of the eighteenth dynasty. (See § 6 (7).) Seven of them were written by Ebed-hepa, King of Jerusalem, about 1360 B. C., and give us a glimpse of that city more than 350 years before David conquered it for Israel. Others of the letters came from other cities of Palestine and Phœnicia, and reveal to us through contemporary documents the conditions there in the patriarchal age. Some of these are translated in Part II, p. 344, ff.