To the east of the main summit the rock changes to a green breccia, which seems to form a considerable portion of that part of the mountain. The view from the summit is a fine one in clear weather, including as it does an extensive prospect of the rugged mountains around, and a large extent of coast-line. But it was on this mountain that I had my first experience of the chronic haze which seems to hang almost perpetually over the coastal regions in the neighbourhood of the tropic, and which is the greatest enemy of the surveyor in these parts. On each of the three days which I spent on Hamata, the morning sun rose over cloud-banks to the east; clouds filled all the wadis and covered the lower country, while the highest peaks stood up clear and sharp above the sea of cloud. Towards 10 a.m., the clouds gradually melted away over the land under the increasing solar influence, but there remained a continuous haze, especially over the coast and out to sea. The explanation of the almost perpetual clouds and haze was soon seen, and is very simple. If the wind blows from the north-west, it is generally cool or even cold in winter. If this north wind is dry and persistent, the air is clear; but should it fail and warm moist breezes set in from seaward, these drop their moisture on reaching the cooler air of the mountains. If the air is still or nearly so, the moisture is evaporated in the sun’s rays during the day, only to precipitate itself again as the air cools by rapid radiation at night. As a consequence, dews on the mountains are extremely heavy, and one soon learns to seek the shelter of an overhanging rock or to improvise a rude tent from a blanket and a few sticks over one’s nightly resting-place. =Gebel Abu Ghusun= is a mountain range north of Hamata, with which it is connected by a ridge of lower peaks so as to close in the small rough granite plain north-east of the latter mountain. Its highest peak, eight kilometres north-north-west of Gebel Hamata, is 1,389 metres above sea-level. It is drained on the south by the Wadi el Abiad, the same tributary of Wadi Huluz which drains the north face of Hamata, and on the north by the Wadi Abu Ghusun, which enters the sea separately. =Gebel Um Laham= is a mass of lower hills a little west of Gebel Abu Ghusun, forming the side of Wadi Huluz opposite to Gebel el Mahali. =Gebel Tarfawi= is a complex mountain range fourteen kilometres north-west of Gebel Hamata. Its highest point, at the north-west end of a ridge, is 1,363 metres above the sea. It is probably drained to the south by the Wadi Tarfawi, a tributary of Wadi Huluz, and to the north by feeders of Wadi Romit.