[Footnote 28: BEADNELL, _Farafra Oasis, its Topography and Geology_, Geol. Surv. Egypt Report, Pt. III, Cairo, 1901.] [Footnote 29: _Découvertes Géologiques Récentes_ etc., p. 850.] [Footnote 30: See the geological map accompanying Zittel’s _Geologie der libyschen Wüste_, Cassel 1883.] CHAPTER IV. * * * * * TOPOGRAPHY OF THE OASIS. As already mentioned in the Introduction, Baharia Oasis is a large natural excavation in the Libyan Desert plateau. Previously existing maps frequently indicate this depression as being open towards the east, but one of the results of the survey expedition has been to show that such a representation is erroneous, Baharia differing from the southern oases in being entirely surrounded by an escarpment, for the most part steep and difficult of ascent. In plan the oasis is of highly irregular outline, more particularly on its western side; but the general shape of the excavation is that of a large oval, with its major axis running north-east and south-west, and with a narrow blunt pointed extension at each end. The extreme length (N.E.-S.W.) is about 94 kilometres, and its greatest width, measured at right angles to its length, some 42 kilometres. The average depth from the general desert plateau-level to the floor of the excavation is rather less than a hundred metres. Thus, though commonly called the “little oasis” in contradistinction to the still larger areas of Farafra, Kharga and Dakhla, Baharia is of considerable size, covering in all over 1,800 square kilometres. Within the excavation, and rising up from its floor, in some cases to a greater height than the bounding scarps, are numerous hills, the larger generally having flat tops and the smaller ones being more or less conical. The cultivated lands, which lie almost entirely around the villages in the north part of the oasis, bear only a very small ratio to the entire oasis-area, probably not exceeding in all, including palm-groves, 11 square kilometres; the remainder of the floor is, however, by no means absolutely waterless or totally devoid of vegetation, as numerous springs exist in certain areas, outside the cultivation-limits, and desert grasses and scrub cover considerable tracts; extensive salines, now mostly nearly dried up, are found in some localities. It will be convenient to consider the topography of the oasis under the following principal heads:— 1. The bounding escarpments; 2. The hills within the oasis; 3. The floor of the oasis, including the villages, hamlets and springs.