94 Se&n&r.

Generally speaking, the kherif (rainy season) may be said to commence early in May, and continue off and on up to the end of October.

In November and December the crops are gathered. The Nile swells fitfully in May, begins to rise steadily in June, and attains its greatest height early in September. Immediately before, and at times during, the • rains, the heat is insupportable, and the air oppressively humid. Then come fever and dysentery, which are most fatal on the argillaceous plain.

Sandy spots near the river, and places on the verge of the rains, are said to be most exempt from disease. The Farantit or Guinea worm, another plague, which comes with the rains, and is here attributed to the use of rainwater, is more frequent south of Sennar (v. p. 62).

In winter the thermometer falls to 60°, and the air becomes very dry.

The climate, tolerably cool, is yet unhealthy, though less so in the direction of Khartum.

The Blue and White Niles do not receive, north of latitude 12°, any notable streams from the intervening watershed. But, as the whole country visibly slopes west, it is probable that some intermittent rivulets flow into the White Nile.

The Blue Nile is joined within the limits of Sennar by the Dinder, and lower down by the Rahad (lightning) or Shimfa, as it is called by the Abyssinians, in whose territories both these streams rise (v. p. 101). They are both great rivers in the rainy season, and when this is over, the Rahad stands in pools.

The villages and settled population of Sennar are nearly all planted on this river, the ordinary width of which varies from 500 to 1,000 yards.

Route IV.—SenkAr Town to Kawa.

(Pruyssenaere, May, 1863.*) A road leads between the White and Blue Mies from Sennar town to Kawa. It takes 5i days' journey ; country near the Blue Nile covered with bush ; wells and waterholes at several places on the road ; used to be much used * In Petermann's " Mittheilungen," 1877, Supplements 50 and 51.