"This is the southern frontier; fixed in the eighth year of the reign of his majesty. Usurtasen [Sesostris], ever living. Let it not be permitted to any negro to pass this boundary northward, either on foot or by boat; nor any sort of cattle, oxen, goats, or sheep belonging to the negroes. Except when any negro comes to trade in the land of Aken, or on any business, let him be well treated. But without allowing boats of the negroes to pass Heh northward forever."[5] In gratitude to the king for thus securing to them safety by repulsing the negroes, the Egyptians sang extravagant hymns to Sostostris. Some of these have been rendered into English, and are regarded as excellent specimens of Egyptian poetry. The following is one of these songs: "Twice joyful are the gods, Thou hast established their offerings. Twice joyful are thy princes, Thou hast formed their boundaries. Twice joyful are thy ancestors before thee, Thou hast increased their portions. Twice joyful is Egypt at thy strong arm, Thou hast guarded the ancient order. Twice joyful are the aged with thy administration, Thou hast widened their possessions. Twice joyful are the two regions with thy valor, Thou hast caused them to flourish. Twice joyful are thy young men of support, Thou hast caused them to flourish. Twice joyful are thy veterans, Thou hast caused them to be vigorous. Twice joyful are the two lands in thy might, Thou hast guarded their walls. Twice joyful be thou, O Horus! widening thy boundary, Mayest thou renew an eternity of life."[6] AMENEMHET III. The greatest name of the Twelfth dynasty is that of Amenemhet III. (1849-1801 B.C.). He directed his attention to internal improvements. Realizing the dire effects upon Egypt when the Nile failed to supply sufficient water or when too much water was forthcoming, he studied various ways of controlling the river. Once or twice in a century the rainfall, always heavy in the Abyssinian highlands, is yet greater; the river rises rapidly to unexpected heights and works general havoc. Or sometimes the supply may be less than usual. Having watched the stream with anxious eyes for many a week, the people behold it recede, although only the adjacent plains have been refreshed and upper portions of the valley lie parched and lifeless, while famine stares Egypt in the face.