being discovered. Each man carries four or five pair of
the bolas; these he throws one after the other at as many
cattle, which, when once entangled, are left for some days
till they become a little exhausted by hunger and struggling.
They are then let free and driven towards a small herd of
tame animals, which have been brought to the spot on purpose.
From their previous treatment, being too much terrified
to leave the herd, they are easily driven, if their
strength last out, to the settlement.

The weather continued so very bad that we determine
to make a push, and try to reach the vessel before night.
From the quantity of rain which had fallen, the surface
of the whole country was swampy. I suppose my horse fell
at least a dozen times, and sometimes the whole six horses
were floundering in the mud together. All the little streams
are bordered by soft peat, which makes it very difficult for
the horses to leap them without falling. To complete our
discomforts we were obliged to cross the head of a creek
of the sea, in which the water was as high as our horses'
backs; and the little waves, owing to the violence of the
wind, broke over us, and made us very wet and cold. Even
the iron-framed Gauchos professed themselves glad when
they reached the settlement, after our little excursion.

The geological structure of these islands is in most
respects simple. The lower country consists of clay-slate
and sandstone, containing fossils, very closely related to, but
not identical with, those found in the Silurian formations
of Europe; the hills are formed of white granular quartz