with my work or keep
on tramp. Then when that one's rested I can make him open and let the
other have a snooze."

"No, no, it won't do," said Mark firmly, much as he would have liked to
have the man's company. "It's my duty to take the watch, and I must
take it."

"Mean it, sir?"

"Certainly," replied Mark. "I wouldn't have it thought that--there, go
away; the doctor's coming back."

The sailor slipped away, and the doctor rejoined the boy, and pointed
out a beat for him which should take him right round the waggons and the
two spans of oxen.

"There," he said, "you know what you have got to do--to fire if there is
any cause for anxiety."

"And I suppose I had better not go too near the river?"

"Oh, I don't know," said the doctor. "It's a mere stream just about
here, though I daresay it's pretty big after rain. Good-night. You
will wake up your cousin at about two. Good-night."

"Good-night," replied Mark, and he felt that his words must have sounded
short to the doctor and full of annoyance, for somehow he thought that
it was not fair for him to go away and leave such a boy as he was; and
besides, it seemed unkind after he had made such a plain allusion to the
river, for the doctor to treat it so lightly. Of course he knew that it
was only a little river, a mere stream; but then it was big lower down,
and what was to prevent any dangerous beast or reptile from crawling up
to lie in wait for anyone that was near?

"Never mind," muttered the boy, "I suppose it's natural to feel a bit
nervous; but I am not going to show the white feather."

He stood still, listening and trying to make out the doctor's step, but
he could not hear a sound.

It was very dark, not a star showing, for a faint mist hung above the
trees, and for a long time the only thing he heard was a stamp that
sounded startling until he made up his mind that it must have been a
fidgety movement on the part of one of the ponies, and shouldering his
rifle, he stepped out slowly so as to pass right round the little camp.

But even that was difficult, for it was not until he was close upon the
waggons that he could make them out, and as he went on the big bullocks
were only represented to him by what seemed to be so many clumps of bush
or heaps of soil.

He walked as slowly as he could so as to make his rounds take up as much
time as possible, and as he came to the end of each traverse he tried to
think out how many minutes it must hav