far to return. Then my foot jammed, and I paused for
breath with my legs and arms cramping rapidly. I remember that I
looked to the west, and saw through the sweat which kept dropping into
my eyes that about half a mile off a piece of cliff which looked
unbroken from the foot had a fold in it to the right. The darkness of
the fold showed me that it was a deep, narrow gully. However, I had no
time to think of this, for I was fast in the middle of my confounded
crack. With immense labour I found a chockstone above my head, and
managed to force my foot free. The next few yards were not so
difficult, and then I stuck once more.

For the crack suddenly grew shallow as the cliff bulged out above me.
I had almost given up hope, when I saw that about three feet above my
head grew the tree. If I could reach it and swing out I might hope to
pull myself up to the ledge on which it grew. I confess it needed all
my courage, for I did not know but that the tree might be loose, and
that it and I might go rattling down four hundred feet. It was my only
hope, however, so I set my teeth, and wriggling up a few inches, made a
grab at it. Thank God it held, and with a great effort I pulled my
shoulder over the ledge, and breathed freely.

My difficulties were not ended, but the worst was past. The rest of
the gully gave me good and safe climbing, and presently a very limp and
weary figure lay on the cliff-top. It took me many minutes to get back
my breath and to conquer the faintness which seized me as soon as the
need for exertion was over.

When I scrambled to my feet and looked round, I saw a wonderful
prospect. It was a plateau like the high-veld, only covered with
bracken and little bushes like hazels. Three or four miles off the
ground rose, and a shallow vale opened. But in the foreground, half a
mile or so distant, a lake lay gleaming in the sun.

I could scarcely believe my eyes as I ran towards it, and doubts of a
mirage haunted me. But it was no mirage, but a real lake, perhaps
three miles in circumference, with bracken-fringed banks, a shore of
white pebbles, and clear deep blue water. I drank my fill, and then
stripped and swam in the blessed coolness. After that I ate some
luncheon, and sunned myself on a flat rock. 'I have discovered the
source of the Labongo,' I said to myself. 'I will write to the Royal
Geographical Society, and they will give me a medal.'

I walked round the lake to look for an ou