INSBCTS, 
479 
myriads spread, the verdure of the country disap- 
pears ; trees and plants are stripped of their 
leaves, and reduced to their naked boughs and 
stems ; and every thing green is as completely 
destroyed as if the country had been exposed to 
the ravages of fire. When these clouds of locusts 
take their flight, the heavens are literally darken- 
ed by them. The celebrated traveller Barrow 
gives a very striking picture of their numbers and 
ravages in Southern Africa. He says, that in the 
part of the country where he then was, for an 
area of nearly SOOO square miles, the whole sur- 
face of the ground might literally be said to be 
covered with them. The water of a very wide 
river was scarcely visible, on account of the dead 
insects that floated on the surface, drowned in the 
attempt to come at the reeds that grew in it. 
They had devoured every blade of grass, and 
every green herb, except the reeds. The year 
1797 was the third year of their continuance in 
Sneuwberg ; and their increase, according to Mr 
Barrow's account, had far exceeded that of a 
geometrical progression, whose ratio is a million. 
For ten years preceding the present visit, this dis- 
trict was entirely free from them. Their former 
exit was somewhat singular. All the full grown 
insects were driven into the sea by a tempestuous 
north-west wind, and were afterwards cast upon 
the beach, where, it is said, they formed a bank 
55 
