there.

Rolling around and searching, I finally discovered a narrow
crevice, into which I shoved the shell. The edge of it was sharp,
and across the sharp edge I proceeded to saw the rope that bound my
wrists. The edge of the shell was also brittle, and I broke it by
bearing too heavily upon it. Then I rolled back to the heap and
returned with as many shells as I could carry in both hands. I
broke many shells, cut my hands a number of times, and got cramps
in my legs from my strained position and my exertions.

While I was suffering from the cramps, and resting, I heard a
familiar halloo drift across the water. It was Charley, searching
for me. The gag in my mouth prevented me from replying, and I
could only lie there, helplessly fuming, while he rowed past the
island and his voice slowly lost itself in the distance.

I returned to the sawing process, and at the end of half an hour
succeeded in severing the rope. The rest was easy. My hands once
free, it was a matter of minutes to loosen my legs and to take the
gag out of my mouth. I ran around the island to make sure it WAS
an island and not by any chance a portion of the mainland. An
island it certainly was, one of the Marin group, fringed with a
sandy beach and surrounded by a sea of mud. Nothing remained but
to wait till daylight and to keep warm; for it was a cold, raw
night for California, with just enough wind to pierce the skin and
cause one to shiver.

To keep up the circulation, I ran around the island a dozen times
or so, and clambered across its rocky backbone as many times more--