I'
I
i S ; '
l l
BELLACO BOCKS— ItEFRACTION.
At W-water there are but eight feet on this rock, which is not
far from mid-channel, just without the entrance.
We anchored near Watchman Cape, and in other places
along the coast, before reaching Port San Julian, and some
time was devoted to an examination of the Bellaco Rock and
its vicinity, as there is a dangerous reef extending from Watchman
Cape towards, but not quite out to the Bellaco.
In my own notes I find this rock mentioned as “ almost
covered at times, but occasionally showing above water as high
as the hull of a ship !” In Mr. Stokes’s journal, left with me,
it is mentioned in these words : “ Passed between the Bellaco
Rocks, close to the eastern one, nearly a -w a s h a n d in the
diary of the Nodales’ voyage (in 1619), it is spoken of as “ una
baxa que lababa la mar en ella,” which means, a rock a-wash.
The rise of tide there is about twenty feet, which explains
the various appearances it had to my eye ; for at high water I
saw it almost covered, or a-wash ; and as the Nodales described
it similarly in 1619, there can have been extremely little, if any,
change in the relative heights of sea and land in this place
during the last two hundred and fifteen years.* Some time ago I
thought differently, having formed a hasty opinion upon the
fact of my having seen the rock as high out of water as a ship’s
huU. I did not then consider how much the tide falls, nor did
I recollect, till I referred to notes, that I had also seen it
a-wash (the top almost level with the water), at times during
the many days we were in the neighbourhood.
On the day that Mr. Stokes and myself made our respective
notes on the Bellaco (without any communication of opinion),
an extraordinary effect of refraction was remarked. The meridian
altitude of the sun (then far south) observed at opposite
horizons, differed no less than sixteen miles ! Similar effects
had been noticed before, especially on the Patagonian coast,
therefore we generally observed both ways; but to nearly
* As the larger and eastern rock is about a hundred yards long and
eighty wide, with kelp growing on most parts of it, I do not think the
top can wear away while so protected by sea-weed.
such an extent as this we never either before or afterwards witnessed
an error arising wholly from the state of the atmosphere
near the horizon; causing the visible water-line to be apparently
raised several minutes of a degree. On these occasions we
always used the mean of the two results, which agreed closely
with the latitude resulting from triangular connection with
points on the shore, whose latitude we knew by observations
made with the artificial horizon.*
7th. Mr. Stokes and I landed some leagues northward of
Port San Julian, near Cape Look-out, and ascended a level-
topped range of hills about 300 feet above the sea. The view
we obtained was similar to those so tiresomely common in
eastern Patagonia. Level, arid, desert-like plains extended
to the horizon : a few irregular hills were seen in the distance;
some guanacoes and a few ostriches were here and there discerned
; a fox crossed our path, and a condor wheeled overhead;
nothing more was noticed.
We returned to the low ground near the sea, and there we
found plenty of small wood, stunted shrubby trees, fit for
fuel; as well as several ponds of fresh-water. The rise of
tide on the shore was considerably more than twenty feet, but
we had not time to ascertain it accurately.
9th. Mount Wood,t that excellent land-mark for Port San
Julian, was seen at daylight: and about noon the Beagle
anchored off the bar of the harbour. Mr. Stokes went with
me to examine the passage, and before evening our ship was
safely moored in the port. This was one, among numerous
instances I could mention, where the good qualities of the
Beagle, as to sailing and working, saved us days of delay,
trouble, and anxiety. All hands immediately set-to about the
plan of the port, and such efficient officers as were with me
made short work of it. One day Mr. Darwin and I under,
took an excursion in search of fresh-water, to the head of the
inlet, and towards a place marked in an old Spanish plan,
* Bellaco rocks are the same as Estevan shoal. There are at least two
distinct masses of rock. A ship may pass between them.
t Nine hundred and fifty feet high.