"Yes," replied Sir John, "I see a cloud is rising, and if the wind should freshen, it might overspread the sky."
"There is not another storm coming, I hope," interposed the Colonel.
"We are in the tropics," said Emery, "and it would not be surprising; for to-night I begin to have misgivings about our observations."
"What is your opinion, Mokoum?" asked the Colonel of the bushman.
Mokoum looked attentively towards the north. The cloud was bounded by a long clear curve, as definite as though traced by a pair of compasses. It marked off a section of some miles on the horizon, and its appearance, black as smoke, seemed to excite the apprehensions of the bushman. At times it reflected a reddish light from the setting sun, as though it were rather a solid mass than any collection of vapour. Without direct reply to the Colonel's appeal, Mokoum simply said that it was strange.
In a few minutes one of the Bochjesmen announced that the horses and cattle showed signs of agitation, and would not be driven to the interior of the camp.
"Well, let them stay outside," said Mokoum; and in answer to the suggestion that there would be danger from the wild beasts around, he added significantly, "Oh, the wild beasts will be too much occupied to pay any attention to them."
After the native had gone back, Colonel Everest turned to ask what the bushman meant; but he had moved away, and was absorbed in watching the advance of the cloud, of which, too accurately, he was aware of the origin.
The dark mass approached. It hung low and appeared to be but a few hundred feet from the ground. Mingling with the sound of the wind was heard a peculiar rustling, which seemed to proceed from the cloud itself. At this moment, above the cloud against the sky, appeared thousands of black specks, fluttering up and down, plunging in and out, and breaking the distinctness of the outline.
"What are those moving specks of black?" asked Sir John.