Situation of Zones without Rain, and of Deserts. 93 
devoid of rain and all vegetation. Thus, the savannahs are 
pretty numerous in the northern districts, and marshes and 
jungles fringe the banks of the river. On the road from 
Ruderpour to Almorah, prickly reeds and resinous trees are 
met with; in Scinde there are springs and melons: the inhabi- 
tants of Beykanir, to the south of Djeypour, have every- 
where cisterns to supply the deficiency occasioned bythe aridity 
of their soil ; lastly, to the east, Delhi, Agra, and the mountain- 
ous country of Khotak, are distinguished in a more positive 
manner by their periodical rains, commencing with storms 
at the end of May, especially abundant in July and August, 
and then becoming less abundant in September ; and it is to 
be remarked, that these regions, situated in the same lati- 
tudes, are moreover extratropical, extending from 23° to 
34° N., being in this respect similar to Affghanistan, Beloo- 
chistan, and Persia. As to the remainder of intertropical 
India, interposed as it is between seas and alpine mountains, 
it cannot, of course, present any thing else but a climate 
composed of alternations of droughts and violent rains ; thus 
fogs, heavy falls of rain, and violent showers of large hail- 
stones are more dreadful in that country than anywhere 
else. 
There now remains no other great desert in Asia but the 
Sehama, which, situated between 30° and 47° N., does not 
necessarily come under our consideration. However, as it is 
generally included along with the tracts already mentioned, 
we think it right to enter into some details on the subject. 
Its height in the eastern portion, between Zakil-Dak and 
Olon Bainchen, hardly exceeds 3650 feet, according to the 
measurement of Bunge, and its mean altitude is not more than 
2500 feet ; while to the west of the lake of Lob, its height is 
scarcely 1200 feet. But this plain is traversed from east to 
west by the two great systems of mountains of Kouenloun 
and Thian-Chan, which tend to modify its temperature ; it is 
divided, moreover, into two halves, an eastern and a west- 
ern, bya less barren narrow tract of country, The following 
- is the manner in which the climates, the soils, and the vegeta- 
tions vary, from east to west, over a great portion of this enor- 
