Gebel Hamata, with one exception[106] the highest mountain in the Eastern Desert of Egypt, is situated on the meridian of 35°, in latitude 24° 12′, thirty-three kilometres from the nearest point of the coast and 213 kilometres from the nearest point of the Nile, and rises to an altitude of 1,978 metres above sea-level; the summit is marked by a triangulation beacon, the position of which is latitude 24° 12′ 17″, longitude 35° 0′ 16″. Gebel Hamata lies some five kilometres east of the main watershed, which curiously enough is not always formed by the highest peaks. It is drained principally by the Wadi Huluz, the heads of which almost encircle it. The Wadi Hamata heads in the eastern face of the high ridge which connects Gebels Hamata and Abu Ghusun, and thus only takes a small portion of the drainage of Gebel Hamata itself. Though surrounded by other high mountains, Hamata towers above them so as to be a very conspicuous feature on the sky line from great distances. Looked at from the north or south, it is like a great, rather flat, cone with a smaller cone east of it. The best way to ascend the mountain is from the head of the Wadi el Abiad, that feeder of Wadi Huluz which drains the north face of it. In proceeding up the Wadi el Abiad from Wadi Huluz, one is shut in by high hills on either side till about six kilometres from the mountain; then the wadi opens into a rough plain with low granite hills, and the imposing mass of Hamata springs suddenly into full view. My camels were coaxed on with their loads up this wadi, which becomes very steep and stony as its head is approached, to within two and a quarter kilometres of the summit, where they actually reached an altitude of 1,025 metres above the sea. The ascent of the remaining 953 metres on foot, though tiring, was fairly easy, and occupied less than four hours. The lower third of Hamata is a whitish granite; this gives place higher up to a hard quartz felsite, which rings under the hammer and weathers into rusty brown blocks. 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.
Gebel Um Heshenib is a great ridge situated twenty-two kilometres north-west of Gebel Hamata. The beacon on its highest point, in latitude 24° 20′ 49″, longitude 34° 50′ 53″, has an altitude of 1,135 metres above the sea. Its lower parts are granite, but the upper third is of dark schists, while the actual ridge on which the beacon stands is a grey porphyrite. Gebel Um Heshenib is drained to the north by the Wadi el Abiad, a tributary of Wadi Gemal, and to the south by tributaries of Wadi Huluz. I ascended it on two occasions from opposite sides. The north approach is the easier road for camels, as they can pass easily up the broad and sandy Wadi el Abiad, while to reach it from Wadi Huluz one has to journey over a rather stony pass and along narrow stony wadis. But the climb is longer from the north side, being one of 635 metres against 380 metres from the south, and the southern climb is easier as well as shorter. It is interesting to note that as the ground south of the mountain lies at an average level of 250 metres higher than that to the north, the plumb-line ought from theoretical considerations to be attracted to the south by several seconds, and this was found to be the case when the mountain was used as a latitude station (see [p. 47]) There is a very difficult pass east of the mountain from the head of Wadi el Abiad into a tributary of Wadi Huluz; I was told that loaded camels could not possibly get over the pass, and have reason to believe the statement true, as although I did not consent my men were desirous of going over it and volunteered to carry the baggage over themselves to relieve the camels.
Gebel el Abiad is the name given to two distinct ranges of high granite hills on either side of the Wadi el Abiad, north and east of Gebel Um Heshenib. The eastern of these two ranges extends in a north-westerly direction for about twelve kilometres from Gebel Tarfawi to near the place where Wadi el Abiad turns to the north-east. It has numerous peaks, of which the most conspicuous is at the south-east end of a high ridge six and a half kilometres north-east of Gebel Um Heshenib, and rises to 957 metres above sea. This eastern range is drained from the west by the Wadi el Abiad, and from the west by the Wadis Shoab and Romit. The western range is slightly lower and less extensive; one of its most conspicuous peaks, eleven kilometres north-north-east of Um Heshenib, is 892 metres above the sea, and there are numerous other peaks further south of almost equal altitude. This western range is almost entirely drained by the Wadi el Abiad, a feeder of which curves round the south end of the range, thus separating it from Gebel Um Heshenib; the drainage from the north end probably passes into the Wadi Mukhatatat, while a portion of the eastern slopes may be drained by feeders of Wadi Durunkat. It is the coarse white granitic sand resulting from the disintegration of the rocks of these hills which gives its name to the Wadi el Abiad, and the hills take their name from the wadi. The heads of the wadi near Gebel Um Heshenib are, however, blackened by hornblendic downwash from the schists which overlie the granite of that mountain.
Gebel Shoab is a very high white granite hill close to the head of Wadi Shoab, on its north side. It rises to 830 metres above the sea, or about 400 metres above the wadi floor.
Gebel Hefeiri is a very sharp granite peak a little west of the Wadi Abu Ghusun, about fifteen kilometres north of Hamata. Rising to 612 metres above the sea, or about 300 metres above the wadi near it, among lower granite hills, it is a good landmark. There is a smaller very sharp peak two and a half kilometres to the north-east, on the opposite side of the Wadi Abu Ghusun, while to the west are sugar loaf shaped hills.
Gebel Um Sueh is a conspicuous granite hill six and a half kilometres east of the Wadi el Abiad and four and a half kilometres north of the Wadi Shoab, rising to 781 metres above sea. It is probably drained from the north-east by the heads of Wadi Um el Abbas.
Gebel Um el Abbas is a very remarkable granite hill between Gebels Um Sueh and Abu Hegilig. From the north, it looks like a square block with precipitous sides, having a sheer drop of about 200 metres. Its summit is 697 metres above sea. It is drained by the Wadi Um el Abbas, which goes independently to the sea.