xxxviii INTKODUCTION. 
which lies in a depression said by the same traveller to embrace an area of at least 
— 000 square kilom. Of the reptiles absolutely nothing is known, but among birds 
he enumerates vultures, ravens, sparrows, the reed-warbler, wagtails, quails, swallowsl 
lapwings, and wild ducks. The products of the soil of this oasis according to Rohlfs 
are the never-absent date-palms, figs, prickly pears, both sweet and bitter oranges, 
lemons, olives, pomegranates, mulberries, the locust-tree, apricots, peaches, carraway- 
seeds, onions, garlic, radishes, turnips, carrots, wheat, oats, rice (sparingly), &c, with a 
little cotton. Acherson, during his visit to this oasis, collected 92 species of plants. 
The climate of Farafreh, according to Rohlfs, is more thoroughly desert than that of 
any of the other oases. The cold at night in winter is great, and the heat in summer 
is unendurable. According to observations made by the same traveller in December, 
the temperature fell to — 4° one night, and rose only to 20° Cent, at midday ; while 
in the middle of March it was also as low as +2° during night, and did not rise above 
23° Cent, in the middle of the day. Slight rain, as in the neighbouring oasis of 
Baharieh, falls in the months of January and February. 
The thermal springs of this oasis have a temperature of about 26° Cent., but although 
they have a metallic taste they afford the best drinking-water of the Libyan desert. 
Rohlfs's expedition first approached the oasis of Farafreh from Assiut. They 
ascended the limestone plateau at Mer, to the north of Assiut, on the 20th December, 
1873, where it has an elevation of 96 metres above the sea. They passed over a 
gravelly desert covered with coarse sand, and between low limestone hills, with Jebe 
Ismail to their left. On this part of the desert they met with a few plants such as 
Traqanitm undatum, Fagonia arabica, Aristida plumosa. Anabasis articulata, Cornulaca 
nionacantha, and a species of Salsola. The desert rises to 118 metres, and, beyond, 
Rohlfs and his party found some shallow wadis and gravelly ground covered with 
sand, in places strewn with Nummulites. Vegetation was still represented by such 
plants as Caroxylon fcetidam, Farsetia cegyptiaca, Calligonum comosum, Ephedra, alata, 
Aristida plumosa, and A. zittelii. Sand-dunes were afterwards encountered running 
north and south, and beyond them more vegetation, the desert continuing to rise 
so that on the 24th December they were at an elevation of 219 metres above the 
sea. The route was still enlivened by the sight of a few plants of species already 
mentioned, and after the travellers had passed some low hills they reached, on the 20th 
December, the watershed between the depression of Farafreh and the Nile, at an 
elevation of about 280 metres above the Mediterranean. A sparse vegetation was still 
present, and after descending 42 metres clown the plateau, they were astonished to 
meet with many trees of Acacia Seyal and numerous plants of Francoeuria crista. 
Beyond this there was a slight ascent to the escarpment of the depression which, at the 
•■ Eng Pass," was found to be 260 metres above the sea. Between the watershed and 
the escarpment they met with distinct traces of rain in the low ground and in the 
hollows in the form of a slimy encrustation several centimetres in thickness. The 
