American citizen. [volume] (Canton, Miss.) 1864-1890, 1875-05-01
Giant Kettles.

It is not always that geological investi-
cations have as their object phenomena
which are of general interest and with
which all are more or less familiar. This
is certainly the case, however, with the
study of the giant kettles" in the neigh
borhood of Christiania, Norway, which
has been lately carried on by Prof. Kjerulf
and soWe of his students. There is hardly
any running stream in our country
of any considerable size which does not
give proof of the power of water and stones
in motion in what are popularity called
pot-holes.' An eddy in the stream
where the current is strong sets few peb-
bles in revolution These commence a
depression into which larger stones fall
and the grinding is continued until cavi-
ty has been produced perhaps several feet
in depth, and almost perfectly round
These are often to be observed, not only
in stream beds, but also in rocks on the
sea shore, where the rush of the tide must
supply the motive force.
The famous giant kettles" of Nor
way are simply "pot-holes'' ON larger
scale and produced in former times un-
der somewhat different conditions than
we have at present. The superstition
OF the people represents them as
having been made by giants. In some
places, where the form is oblong and IT.
regular, fancy has seen in them the foot
prints of these monsters, while in one
place, where the road goes directly
through very large kettle, the saying is
that there St. Olaf turned his horse
around. On the west coast of Norway an
other name is used, and they are spoken
of as giants chairs.
The description of one of these kettles
examined by Prof Kjerulf will give
some idea as to their size and general
character. AT the surface it had a diam
eter of about eight feet, being slightly
elliptical in form. 1t widened consider
ably in the descent, and then contracted
again at the bottom 1t is interesting to
note that the walls were distinctly worked
out in a spiral, which could be traced
from top to bottom. In the case of some
other kettles examined the spiral was so
perfect that the cavity could be compared
to the impression of a gigantic snail.
The total depth of the kettle in ques-
ton from the highest point of the margin
was forty-four feet, the axis inclining
as is always the case, with gravel and
broken rock, though toward the bottom
numerous so-called grinding stones were
found, some of them 300 pounds in weight,
and all smooth and elliptical in shape 1t
was through their revolution that the ex-
cavation had been made. 1t required
three men working for fifty days to clear
yld0t kettlc Oh us contents, anu The
whole amount taken out was estimated at
1850 cubic feet, some of the stones being
SO large that they had to be mined before
they could be hOisted out
The kettles in general present much the
same features as the one which has been
just described, though there is a great
variation in ratio of width to depth many
of them being shallow, larger at the top
than at the bottom, and very properly are
called kettles, while others, as the one al
luded to, are deep, and could better be
called wells. 1t Is to be observed that
they are found by no means necessarily in
present river channels. They are most
common in the neighborhood of the great
fiords, though they have been observed too
at a height of !, 200 feet above the sea- In
regard to their origin, the best authorities
refer it to the time when the land was COW
cred by enormous glaciers, such as exist
at the present time in the upper part of
Greenland The melting of the ice on the
surface of glaciers gives rise to consider
able rivers, and as these find some crevasse
in the ice they descend with violence, and
it is conceivable that such stream strik-
ing the bed rock below might be the
means, with the masses of rock they would
put in motion, of producing the enormous
cavities which are now observed This
theory as carried out by its supporters
meets with some difficulties, but seems to
be the best which has been proposed