27 
TRANSLATIONS AND NOTICES OF 
MEMOIRS. 
= 
THe SAHARA AND ITS DIFFERENT TYPES OF DESERTS AND OASES. 
By E. Drsor, Professor of Geology, &c., Neufchatel.* 
[Translated, with notes, by A. C. Ramsay, F.R.S., F.G.8., &e.] 
HE following memoir, by Professor EK. Desor, of Neufchatel, is 
only partly geological, but the greater portion of the remainder 
is so intimately connected with those questions of physical geography 
with which modern geologists are so much occupied, that I have 
thought it would be interesting to geologists in general, especially 
those parts that treat of the origin and nature of the Sahara, the 
Oases, and the underground sheets of water supplying the artesian 
wells. Ihave therefore translated the sketch in full. The Sahara, 
its salines, and other features, as well as the artesian borings, have 
formed the subject of several memoirs, by MM. Desvaux and Ville, 
in the Annales des Mines, 5™° Série, vols. xiv. and xv., 1858-59.— 
A.C. R. 
I cannot pretend to describe all the aspects of the great Desert of 
Sahara. Such a district would require repeated journeys, and pro- 
longed visits under conditions but little favourable to study, and 
necessitate a perseverance and devotion to science not often met with. 
Now, my travelling companions and myself have only seen a little 
corner of this strange country, in a rapid excursion as far as the 
limits of the French possessions. If, however, putting together our 
experiences as travellers and naturalists, we are able to present some 
new features of this unique country, interesting equally in a geogra- 
phical, botanical, or geological point of view, our success is in a 
great measure owing to the protection and encouragement so kindly 
showed us by General Desvaux, Governor of the Province of Con- 
stantine, as well as to the enlightened solicitude of Captain Zickel, 
Director of the artesian borings in the desert. 
Those parts of the desert which we visited are—the zone which 
borders the chain of the Aurés, comprising the Oases of Zibans, the 
route from Biskra to Tuggurt across the little desert, Wady Rit, 
and its oases, the Oases of Souf, and the route from Souf to Biskra, 
passing the Chott-Melrir. 
In this itinerary the observing traveller will recognize three types 
of desert to which three types of oasis correspond: 1st. The desert 
of the plateau ; 2nd. The desert of erosion ; and 3rd. The desert of 
dunes. 
The Desert of the Plateaux, between Biskra and Wady Rir, pre- 
sents a plain stretching as far as eye can reach, strewed with pebbles 
* Le Sahara; ses différents types de Déserts et d’Oasis; par E. Desor. (Ex- 
trait du Bulletin Soc. Science. Nat., Neufchatel, 1864.).—Several paragraphs, not 
relating to the geological part of the memoir, have been omitted,—Enir, 
