"I know that. He can't bray. He whinnies and squeals; but he tries to bray, and opens his mouth just like you do."

"Perhaps so," said Ned, changing the conversation at once. "I say, doesn't that peak look beautiful? It's just as if it is red-hot."

"You'd find it pretty cold if you were up there," said Chris, giving up making rude allusions to his companion's yawning.

"Yes; that always seems to me so strange," said Ned.

"What does?"

"That the nearer you get up to the sun the colder it is. It ought to be hotter."

"Don't find fault with nature," said Chris dogmatically. "I wasn't finding fault. I only say it seems queer. I want to thoroughly understand why it is."

"Ask your father, he knows."

"I did," said Ned, "and he said it was because the atmosphere was thinner, the higher you get."

"Then the lower you get I suppose the thicker it is," said Chris thoughtfully, "and that's why it's so thick and hot down there on the salt desert. Oh, my word, how it used to scorch! It was just as if the haze was one great burning-gla.s.s."

"Oh, I say," cried Ned dolefully, "I wish you wouldn't."

"Wouldn't what?"

"Talk about the heat on the salt plains. We're going to start off afresh to-morrow morning, and I shall begin dreaming about what we went through over yonder."

"Poor old chap!"

"Ah, you may laugh, but it'll all come back like a nightmare, with the burning thirst and giddiness, and the black spots before one's eyes."

"That's biliousness," said Chris, speaking authoritatively, like a doctor's son.

"I don't care what it is. It's very horrible," said Ned, "and if I thought we were going through a time like that again I should want to stop at home."

"Where's that?" said Chris dryly.

"Ah, to be sure," said Ned, with a sigh. "I forgot where we were. I suppose there'll be no home again till we've found the gold."

"And that won't be to-night," said Chris, as a shrill whistle rang out through the clear evening air. "There's old Griggs calling us just as if we were dogs. I've a good mind not to hear."

But Chris answered the whistle all the same, and the boys were soon after joined by the American, who had come to meet them, and his first words were--

"Now, boys, bed and a good long sleep. We're off again at daybreak."

CHAPTER THIRTY TWO.

PETRA THE SECOND.

Daybreak came all too soon for Chris, who sprang up rubbing his eyes and yawning, in response to a summons from Griggs, who stood over the boy like a black figure cut out of cardboard showing against a ruddy glow.

"Why--oh bother! It can't be time," cried the boy.

"Yes, it is, and we're late."

"So we are. You said daylight, and the sun's rising."

"Is it?" said Griggs. "Then it's before its time. There, unb.u.t.ton your eyelids and look again. The sun doesn't crackle and spit when it gets over the world's edge."

"Humph!" grunted Chris, as he realised the truth that a roaring fire of pinewood was burning in a sheltered spot. "Have you woke Ned?"

"Yes, and he's growling for his breakfast. Going to have a sluice first? You'll just have time."

Griggs went back to see after the breakfast, and Chris turned to where Ned had lain down on a fragrant pine-bough couch.

"Here, look sharp," he said. "I suppose we must have a dose of cold water."

Ned grunted and seemed as ill-humoured as his companion at being awakened from sleep, and the pair hurried through the gloom to the side of the gully, where there was a soft, splashing roar caused by water falling like so much foam from a ledge about a hundred feet above their heads into a rock-pool at their feet.

The boys' preparations did not take long, neither did the application of their bath. Chris stepped into the rock-pool, took a couple of paces, and stood right in the middle of the descending broken water, uttered a gasp or two, stepped out, and began to apply a rough home-made towel with tremendous energy.

"Is it cold?" said Ned, with a preliminary shiver.

"Ugh! Horrid!" was the smothered reply.

The words seemed to check Ned, but the shock had to be suffered, and he too stepped into the natural shower-bath, and sprang out again, to follow his companion's example.

"Feel sleepy now?" cried Chris, with a laugh, and in quite a different tone of voice.

"Sleepy? Who could?" was the reply, punctuated with gasps. "My! Isn't it icy this morning!"

"Yes. Washed all the snarl out of you, old chap," cried Chris merrily.

"I say, you did sound disagreeable."

"Oh, I like that!" said Ned. "Why, a bear with a sore head was nothing to you."

"Humph!" grunted Chris, feeling too guilty to defend himself. "I say, feel cold now?"

"No; burning hot," was the reply. "I say, what a pity there are not falls like this all over the salt desert."

"There'd be no salt desert if there were," said Chris, who was now dressing rapidly in the increasing light. "They'd soon wash all the salt away. Look sharp: old Griggs will be shouting directly."

The word "Breakfast!" came almost as he spoke, and as the boys hurried towards the fire, fully alert now and ready for anything, they saw that the mules were all laden but the one which carried the kitchen, as they called it, and this beast was feasting in company with the ponies.

"Oh, I say, father, it isn't fair," cried Chris, in response to the morning greeting. "You know I like to help load."

"Yes, my boy, but we woke earlier than usual, and I wanted you two to have a good rest, for we shall have a long day."

Ned was making a similar protest to his father, who responded by telling him that he would be tired enough before night.