INTERIOR OF AFRICA. I35 
tent. Over the grave, they plant one particular shrub ; and no 
stranger is allowed to pluck a leaf, or even to touch it ; so great 
a veneration have they for the dead. 
April 7th. About four o'clock in the afternoon, a whirlwind 
passed through the camp, with such violence that it overturned 
three tents, and blew down one side of my hut. These whirl- 
winds come from the Great Desert, and, at this season of the 
year, are so common, that I have seen five or six of them at 
one time. They carry up quantities of sand to an amazing 
height, which resemble, at a distance, so many moving pillars 
of smoke. 
The scorching heat of the sun, upon a dry and sandy country, 
makes the air insufferably hot. Ali having robbed me of my 
thermometer, I had no means of forming a comparative judg- 
ment ; but in the middle of the day, when the beams of the 
vertical sun are seconded by the scorching wind from the 
Desert, the ground is frequently heated to such a degree, as 
not to be borne by the naked foot ; even the Negro slaves, 
will not run from one tent to another, without their sandals. 
At this time of the day, the Moors lie stretched at length in 
their tents, either asleep, or unwilling to move ; and I have 
often felt the wind so hot, that I could not hold my hand in the 
current of air which came through the crevices of my hut, 
without feeling sensible pain. 
April 8th. This day the wind blew from the south-west, 
and in the night there was a heavy shower of rain, accompanied 
with thunder and lightning. 
April 10th. In the evening the Tabala, or large drum, was 
