Some, torn from Canada, have been carried five
hundred miles away, as far as Ohio, in the thirty-
eighth degree of latitude; others, stripped from
Labrador, have been cast on the southern coast
of the Gulf of St. Lawrence; red sandstone,
plucked from Prince Edward's Island, now lies
in Nova Scotia. Innumerable fragments, twenty
or thirty feet thick, have made shipwreck in
fifty degrees, at an altitude of a hundred yards.
New England can show blocks of considerable
size that are situated four hundred yards higher
than the rocks from which they come. In
Europe, enormous masses, detached from the
mountains of Sweden and Finland, are dispersed
in prodigious numbers over Germany, Poland,
and Russia. On the south side of Lake Onega
blocks are seen which form part of the opposite
coast. Erratic boulders are found as far to the
south as the forest of Fontainebleau—whence a
few have been retransported northwards, by
human agency, to decorate the Bois de Boulogne
and other Parisian promenades.

Immense tracts of transported materials,
consisting of sand, gravel; shingle, clay, mud, and
all sorts of sweepings off the face of the earth,
and incrusted with erratic boulders, cover vast
regions to a depth which attains as much as
three hundred yards, forming sometimes grand
horizontal plains, sometimes lines of hills stretching
along from north to south. The steppes of
Russia, the sands of Gascony, and the stratum
of sand and clay, more than two hundred yards
thick, which covers Holland, belong to this
deposit. In England we have examples of diluvium
on a tolerably extensive scale. A celebrated
living professor said, truly, that Norfolk is
nothing but a heap of rubbish.

Mysterious marks, stripes, furrows, and
flutings, sometimes two feet deep, have been
scooped out by an irresistible chisel in the
granite flanks of mountains that have been
ground down, smoothed and polished, by the
agency of an anonymous workman. The
constant direction of these marks is north and
south. The phenomenon is especially remarkable
in Finland, in Sweden, in Norway, and the
British Islands. Such is the collection of facts
which constitute the diluvium.

The explanations hitherto given of these facts
have only contained a portion of the truth. That
they are the effect of Agassiz's grand polar glacier
is scarcely admissible; because, although glaciers
do slide down valleys in the Alps, this glacier
would not have stirred on a vast horizontal
plain. What was wanted, was a theory which
should explain and account for the whole of the
phenomena, observed. A step towards it was
recently made. In a report by M. Elie de Beaumont
on an able Mémoire from M. Durocher, it
is proved that the force which produced the
diluvium proceeded from the regions in the
neighbourhood of the North Pole; that an
immense mass of waters, accompanied by ice,
and rushing from north to south, inundated the
northern countries of the globe, from Greenland
to the Ural Mountains, stripping the highlands,
polishing and channelling the rocks by means of
the detritus which it hurried along with it, rolling
in its waves the immense alluviums which
constitute the soil of grand valleys, and lastly
transporting enormous blocks by the aid of
icebergs. The Baltic annually offers a similar
spectacle, when the ice breaks up in spring;
masses of granite embedded in the ice are carried
by the currents to great distances. Dr. Scoresby,
during his voyage to Greenland, saw icebergs, a
hundred feet high, so laden with stones and
rocks, that the ice itself was almost invisible.

What is the cause of the extreme cold which
once reigned in our hemisphere? What force
set in motion the torrents which have ravaged
it? Why did that motion set out from the
polar regions, proceeding in a southern direction?

M. Adhémar replies: During ten thousand
five hundred years, the sum of the hours of night
in our hemisphere preponderating over the sum
of the hours of day, an immense cupola of ice
was formed over and around the North Pole.
It reached lower than the seventieth degree of
latitude. It gave to the arctic rocks their
peculiar aspect as we now behold them. The
attraction of this grand glacier had drawn to
this side of the equator, almost the totality of
the seas, whose level stood much higher than it
now does. Our continents were for the most
part under water, whilst those of the southern
hemisphere were high and dry, and perhaps were
inhabited by the human race which was
destroyed at the last deluge. Seven thousand years
before that deluge, the arctic glacier had
attained its greatest development. From that
date, the sum of night hours in our hemisphere
diminishing, and the sum of day hours increasing,
our hemisphere became warmer, the extent
of the great glacier was gradually decreased,
while an opposite effect was taking place at the
South Pole. After the lapse of seven thousand
years, the continued action of the sun's heat
having sufficiently softened the North-Polar ice,
the grand break-up occurred; the northern seas
and the fragments of the glacier, obeying the
sudden displacement of the centre of gravity,
rushed in a body towards the south. Torn
from his bed, Ocean carried with him his
mud, with which he formed the extensive lands
of transport which constitute the diluvium.
Gigantic streams of water, mingled with earth,
sand, and pebbles, formed the alluviums of the
great valleys; finally, erratic boulders, sustained
by the ice and by the boiling up of the arctic
waters to the altitudes which they now occupy,
remained shelved on the sides of mountains
whose tops they were unable to scale. Thus
was produced the last deluge, four thousand two
hundred years ago.

But this is not all. Suppose a traveller
journeying from the North Pole to the South Pole,
along any one given meridian. He will tell you
that, in proportion as he gets further and further
from the pole, his starting-place, erratic boulders
become fess and less numerous in our
hemisphere; that they are already scarce about the
thirty-fifth degree of latitude, and that from that
point to the equator they are almost completely