The geological examination of the Oases of the Libyan Desert was commenced in 1897, when two parties were sent out to Baharia Oasis, one under the charge of Dr. Ball, who, with Mr. G. Vuta as topographer, started from Minia and explored the eastern half of the area, while Mr. Beadnell with Mr. L. Gorringe as his topographer started from Maghagha and examined the western side of the oasis. The expeditions commenced work in October, and mapping on the scale of ¹⁄₅₀₀₀₀ the whole area was surveyed before the end of the year. The return traverses were made to Minia by the first party via Farafra to Assiut by the second. The following chapters and maps set forth the results of this joint exploration, certain gaps being filled from the data of Ascherson. * * * * * BAHARIA OASIS * * * * * CHAPTER I. * * * * * INTRODUCTION. The Oasis of Baharia (or Northern Oasis), also known as the Little Oasis, lies between the parallels 27° 48′ and 28° 30′ of north latitude, and between the meridians 28° 35′ and 29° 10′ east of Greenwich, being thus situated in the Libyan Desert about 180 kilometres, or four to five days’ march by camel, west of the Nile Valley (Sketchmap, Plate II). Like the other oases of the Western Desert (Farafra, Dakhla and Kharga) to the south, Baharia is a large natural excavation in the great Libyan plateau; it differs, however, from those oases, which are open on one or more sides, in being entirely surrounded by escarpments, and the vast number of isolated hills within the depression form an unique topographical feature. In Baharia, as, with the exception of Dakhla, in the oases generally, the cultivated area bears only a very small proportion to the total oasis-area, the remainder of the floor of the natural excavation being barren desert. The oasis contains four principal villages, all situated in its northern portion, and it is in the neighbourhood of these that water, and consequently vegetation, is most abundant.