Above the springs, Wadi Meneiga soon becomes impassable, ending in rocky gorges in the mountains. Below the springs it courses for about seven kilometres in a direction a little west of north to join Wadi Korbiai and form the head of Wadi Kreiga. The fall in this seven kilometres is 200 metres, so that the slope is the phenomenally rapid one of twenty-eight metres per kilometre, and of course the floor of the wadi is very stony and camel progress is very slow. There are several lateral feeders, including one from the east, three kilometres below the springs, leading to the head of Wadi Radad; but I am not sure whether the pass is practicable as I only saw it from the mountain top. From the mouth of Wadi Meneiga, Wadi Kreiga courses about 15° north of east, as a fairly wide wadi with a stony floor, with high hills on either side from which small feeders enter. The first large feeder, the =Wadi Abiad=, enters from the north-west, six kilometres below the mouth of Wadi Meneiga; it is a steeply falling wadi, which, like all wadis bearing the name of Abiad, has a floor of light-coloured granitic sand. Some eight kilometres lower down, two feeders enter from opposite sides: that from the north is called =Wadi Eberer=, while that from the south bears the name of =Wadi Shigeg=. Neither of these has been followed up far, and their length is unknown; but they are believed to be of no great extent. Below this point the country opens out considerably, and the wadi anastomoses round low hills, while its floor becomes less stony and more easy under foot. The various channels unite again about eight kilometres further down, where the wadi receives a tributary from the north-west just before it passes the high hill mass which forms the southward extension of Gebel Beida. This tributary leads to an easy pass, forming a direct road to Bir Beida. Lower down several lateral feeders come into Kreiga from either side, and the wadi emerges on to a sandy plain with scattered low hills. Across this plain Kreiga takes a more northerly direction for about sixteen kilometres to join the Wadi Hodein. The length of Wadi Kreiga from the mouth of Wadi Meneiga to Wadi Hodein is about fourty-one kilometres. Its fall between these points is from 405 metres to about 70 metres above sea-level, giving an average slope of eight metres per kilometre; the slope in the upper parts, where the wadi bed is stony, is of course somewhat greater, and that in its lower more sandy reaches is somewhat less than this average. =Wadi Kolaiqo= is a very ill-defined drainage line heading in the low hills called Gebel Kolaiqo, and coursing north-east for about thirty kilometres across the sandy coast-plain to reach the sea about latitude 23° 0′. It is very sandy, and absolutely barren except for a little scrub in its upper parts. It would hardly have been noticed had not the triangulation station on the hill at its head been occupied.