the innumerable pebbles alone would prove long-continued action. But how
the whole mass of shingle on the coast-plains has been transported from the
mountains of the interior, is another and more difficult question. The
following considerations, however, show that the sea by its ordinary action
has considerable power in distributing pebbles. Table 3 above shows how
very uniformly and gradually the pebbles decrease in size with the
gradually seaward increasing depth and distance. (I may mention, that at
the distance of 150 miles from the Patagonian shore I carefully examined
the minute rounded particles in the sand, and found them to be fusible like
the porphyries of the great shingle bed. I could even distinguish particles
of the gallstone-yellow porphyry. It was interesting to notice how
gradually the particles of white quartz increased, as we approached the
Falkland Islands, which are thus constituted. In the whole line of
soundings between these islands and the coast of Patagonia dead or living
organic remains were most rare. On the relations between the depth of water
and the nature of the bottom, see Martin White on "Soundings in the
Channel" pages 4, 6, 175; also Captain Beechey's "Voyage to the Pacific"
chapter 18.) A series of this kind irresistibly leads to the conclusion,
that the sea has the power of sifting and distributing the loose matter on
its bottom. According to Martin White, the bed of the British Channel is
disturbed during gales at depths of sixty-three and sixty-seven fathoms,
and at thirty fathoms, shingle and fragments of shells are often deposited,
afterwards to be carried away again. ("Soundings in the Channel" pages 4,
166. M. Siau states ("Edinburgh New Philosophical Journal" volume 31 page
246), that he found the sediment, at a depth of 188 metres, arranged in
ripples of different degrees of fineness. There are some excellent
discussions on this and allied subjects in Sir H. De la Beche's
"Theoretical Researches.") Groundswells, which are believed to be caused by
distant gales, seem especially to affect the bottom: at such times,
according to Sir R. Schomburgk, the sea to a great distance round the West