A goodly portion of the fourth opening into the little kraal was filled
up by the large fire which was burning for the protection of the
bullocks and ponies, and thoroughly lit up the camping place, but in
return for its protection extorted the suffering from the heat, not only
in front but reflected down from the rocks behind.

"Yes," said Dean, "it is rather a roaster. Couldn't we let it out now?"

"No," said the doctor decisively. "I have just been outside to have a
look round with Mak. We were only out for a few minutes, and the black
caught me twice by the arm to listen."

"Well, did you hear anything?" said Mark.

"Yes; lions."

The boy made a movement as if to reach his rifle.

"You need not do that," said the doctor, "for the sounds were distant.
Still, lions travel fast, and we might have a visit at any time; so you
see that you have an answer to your proposal about letting the fire
out."

"Yes," said Dean; "that settles it."

"Besides," said the doctor, "we should not be any cooler if there were
no fire."

"Oh-h-h!" said Mark, in a tone that suggested doubt.

"Don't be too sceptical, my boy," said the doctor. "Let me prove it to
you. Come a little nearer the fire."

The doctor had led the way, and together they stood so near to the
glowing flames that they looked to those whom they left behind like a
pair of figures cut out of black cloth.

"Now," said the doctor, "how do you feel?"

"As if my face would be scorched if I stopped here."

"Nothing more?"

"Oh, yes," said Mark; "I feel quite a cool wind blowing into my neck."

"Exactly," said the doctor. "As the heated air rises from the fire the
cool air from the veldt rushes in to take its place. Why, don't you
remember when the haystack was on fire at the farm at home how we went
to see it, walked close up, and felt the cold wind rushing towards the
flames so that you had a stiff neck the next day?"

"Of course! I had forgotten that," said Mark, laughing. "Well, we must
put up with the fire, I suppose."

The watch was set that night, and fell to the lot of Sir James, who took
up his post near the fire, rifle in hand, while every man lay down with
his piece by his side, for three times by sounds much nearer, the
animals were made uneasy. The bullocks couched close to the trek-tow
and the ponies stamped restlessly again and again from where they were
haltered to one of the wheels inside the enclosure and close up to the
granite w