(M30) The cutting of the dams and the admission of the water into the canals and fields is a great event in the Egyptian year. At Cairo the operation generally takes place between the sixth and the sixteenth of August, and till lately was attended by ceremonies which deserve to be noticed, because they were probably handed down from antiquity. An ancient canal, known by the name of the Khalíj, formerly passed through the native town of Cairo. Near its entrance the canal was crossed by a dam of earth, very broad at the bottom and diminishing in breadth upwards, which used to be constructed before or soon after the Nile began to rise. In front of the dam, on the side of the river, was reared a truncated cone of earth called the _’arooseh_ or “bride,” on the top of which a little maize or millet was generally sown. This “bride” was commonly washed down by the rising tide a week or a fortnight before the cutting of the dam. Tradition runs that the old custom was to deck a young virgin in gay apparel and throw her into the river as a sacrifice to obtain a plentiful inundation.(74) Certainly human sacrifices were offered for a similar purpose by the Wajagga of German East Africa down to recent years. These people irrigate their fields by means of skilfully constructed channels, through which they conduct the water of the mountain brooks and rivers to the thirsty land. They imagine that the spirits of their forefathers dwell in the rocky basins of these rushing streams, and that they would resent the withdrawal of the water to irrigate the fields if compensation were not offered to them. The water-rate paid to them consisted of a child, uncircumcised and of unblemished body, who was decked with ornaments and bells and thrown into the river to drown, before they ventured to draw off the water into the irrigation channel. Having thrown him in, his executioners shewed a clean pair of heels, because they expected the river to rise in flood at once on receipt of the water-rate.(75) In similar circumstances the Njamus of British East Africa sacrifice a sheep before they let the water of the stream flow into the ditch or artificial channel. The fat, dung, and blood of the animal are sprinkled at the mouth of the ditch and in the water; thereupon the dam is broken down and the stream pours into the ditch. The sacrifice may only be offered by a man of the Il Mayek clan, and for two days afterwards he wears the skin of the beast tied round his head. No one may quarrel with this man while the water is irrigating the crops, else the people believe that the water would cease to flow in the ditch; more than that, if the men of the Il Mayek clan were angry and sulked for ten days, the water would dry up permanently for that season. Hence the Il Mayek clan enjoys great consideration in the tribe, since the crops are thought to depend on their good will and good offices. Ten elders assist at the sacrifice of the sheep, though they may take no part in it.