nusually abundant influx of river water, or when these causes have
combined, that this sea is made to rise two or three feet above its
standard level. The fluctuations due to these causes are nearly the same
from year to year; so that the pilots and fishermen believe and
apparently with reason, that they can mark a deviation, even of a few
inches, from the ordinary or mean height of the waters.

There are, moreover, peculiarities in the configuration of the shores of
Norway and Sweden, which facilitate in a remarkable degree the
appreciation of slight changes in the relative level of land and water.
It has often been said, that there are two coasts, an inner and an outer
one; the inner being the shore of the main land; the outer one, a fringe
of countless rocky islands of all dimensions, called the skar (_shair_).
Boats and small vessels make their coasting voyages within this skar:
for here they may sail in smooth water, even when the sea without is
strongly agitated. But the navigation is very intricate, and the pilot
must possess a perfect acquaintance with the breadth and depth of every
narrow channel, and the position of innumerable sunken rocks. If on such
a coast the land rises one or two feet in the course of half a century,
the minute topography of the skar is entirely altered. To a stranger,
indeed, who revisits it after an interval of many years, its general
aspect remains the same; but the inhabitant finds that he can no longer
penetrate with his boat through channels where he formerly passed, and
he can tell of countless other changes in the height and breadth of
isolated rocks, now exposed, but once only seen through the clear water.

The rocks of gneiss, mica-schist, and quartz are usually very hard on
this coast, slow to decompose, and, when protected from the breakers,
remaining for ages unaltered in their form. Hence it is easy to mark the
stages of their progressive emergence by the aid of natural and
artificial marks imprinted on them. Besides the summits of _fixed_
rocks, there are numerous erratic blocks of vast size strewed over the
shoals and islands in the skar, which have been probably drifted by ice
in the manner before suggested.[736] All these are observed to have
increased in height and dimension with the last half century. Some,
which were formerly known as dangerous sunken rocks, are now only hidden
when the water is highest. On their first appearance, they usually
present a smooth, bare,