A lecture delivered at the Monterey Assembly, Pacific Grove Retreat,
California, 1883.
By C. L. ANDERSON, M.D.
[Concluded.]
Whilst these “rivers in the ocean” are flowing more or less rapidly
toward the Arctic regions, there are undercurrents moving slowly but
irresistibly toward the equator, or at least in a direction to restore
the equilibrium of waters. That these undercurrents come from the poles
is already demonstrated by the thermometer. At certain depths under the
equator the temperature is as low as 35° or 36° F. This low temperature
could not be maintained unless supplied from the Polar regions. Fresh
water freezes at 32° and salt water, that is sea water, at about 27°,
according to the density. In many places north of England, Dr. Carpenter
found the lower depths at a temperature of about 29°. He speaks of an
ocean river 2,000 feet deep, colder than the freezing point of fresh
water. Why could not this low temperature be maintained without supposing
a supply from the Polar regions? The temperature of the earth’s crust
twenty or thirty feet from the surface is quite uniform at 50° to 55°
all over the temperate zones. At that depth—say thirty feet—it is not
deep enough to be influenced by “the internal heat” of the earth, which
we experience in going down into mines, or which shows itself in the hot
water from very deep springs, and yet it is sufficiently covered so as
not to be influenced by seasonable changes. The water would naturally
take the temperature of the earth’s crust. This has been proven in the
case of the Mediterranean Sea. This body of water is shut off from the
general circulatory system by the Strait of Gibraltar, which is so
shallow at its outlet that no communication between the deep water of
the Mediterranean and the Atlantic can possibly take place. This great
“middle earth sea” is at some places 11,000 to 12,000 feet deep. And
yet Dr. Carpenter found the temperature in August and September 78° at
the surface; and by going down with the thermometer the heat gradually
diminished, until at the depth of 600 feet the temperature was 55°. From
this point, curious as it may appear, there was no change in heat until
the bottom was reached. Whatever was the temperature at 600 feet it was
the same all the way down. He then ascertained that the temperature of
the earth’s crust in that region was 54° and 55°.
This shows pretty clearly that depth of water alone does not produce the
coldness found in the seas having connection with the Polar regions.
But there are other ways of demonstrating this lower cold current. At a
meeting of the Geographical Society Dr. Carpenter exhibited in a simple
and minute way these warm and cold currents. He had a trough constructed
with plate glass sides, about six feet long, a foot deep, and the sides
not more than one inch from each other. At one end of this trough a
piece of ice was wedged in between the two sides. That represented the
Polar area. At the other end heat was applied by a bar of metal laid on
the upper surface of the water, and the end carried over the trough and
heated with a spirit lamp—to represent the equatorial area. Then some
coloring matter was put in the water; red at the warm end, and blue at
the cold end. Now what took place? The water tinged with blue, put in
at the surface of the Polar area, being subject to a cold atmospheric
temperature immediately fell to the bottom. It then crept slowly along
the bottom of the trough, and at the warm end it gradually rose toward
the surface, and gradually returned along the surface to the point from
which it started. The red followed the same course as the blue, but
started from a different point. It crept along the surface from the
Equatorial to the Polar end, and there fell to the bottom, just as the
blue had done, and formed another stratum, creeping along the bottom
and coming again to the surface. Each color made a distinct circulation
during the half hour that the experiment was under observation.
Now this is an experiment that can be repeated in our parlors without
going down to the Equator or up to the North pole; an additional proof
that we often have the very thing at our doors that we travel thousands
of miles to find.
Until the last four or five years the opinion prevailed that the ocean
was barren of life at great depths. Continued researches, however, find
that many forms and great profusion of life exists at a depth of two
and three miles. This deep water life seems to be adapted to the low
temperature near the freezing point of fresh water—and the forms are
usually very small, requiring thousands to weigh a grain. There is an
exuberance of that small animal known as _globagerina_—the little animal
that secretes carbonate of lime for a covering, and makes pretty much
all our chalk beds. The well known “White Cliffs of England” were made
by this little animal, and in the deeper portions of the Atlantic it is
still at work. Some day when the ocean’s bed is raised a few thousand
feet these beds of chalk will appear and be exactly like the chalk of the
_cretaceous period_, so much talked of and written about by geologists.
Again, there are other animals dredged lately in larger quantities at a
great depth, 3,000 and 4,000 feet, belonging to the sponges. These are
busy in making _flints_—or such material as flints are composed of.
So we find in this large aquarium, the great sea, the same processes
going on—the same material manufactured that took place in what is termed
the older geological formation. Can we say that creation is complete?
That the earth is finished, and, like a ship we read about the other day,
to be disposed of for the old iron it contains? Not long since I visited
a marble quarry, from which very curious and beautiful marble, resembling
the onyx, was being taken. There were thick strata cropping out; and the
air, and rain, and frost had disintegrated the exposed parts, so they
looked as old as the earth. But just beneath, and in various places, were
little springs of warm water, and as these bubbled out of the earth they
deposited on cooling and exposure to the air, the same kind of marble—and
there I saw going on the process of marble making that had continued
doubtless for thousands of years.
On the shores, in the tide, pools and lagoons of Monterey bay we often
gather little plants classed with the _Algæ_, or sea-moss, which we call
diatoms. They are exceedingly small—some of them—so that we have to
magnify them with the microscope several hundred diameters, in order to
see how they are formed. Some kinds grow on the larger sea weeds, some
on the rocks, and some appear to be free in the water, coming ashore in
large quantities with the foam of the surf, and giving a greenish brown
color to the sand of the shore. These diatoms are composed mainly of
silex—flint. If we examine the rocks of our highest ridges and mountains
and the cliffs of our shores in places, with the microscope, we shall
find them largely composed of fragments of diatoms and spiculæ of
sponges. And these are chiefly of the same species that we find alive
to-day. Thus while the “chalk rocks” on our shores, the sand stones and
harder rocks are melting away under the pounding waves of the sea, and
being carried to the lower bottoms, fresh supplies of diatoms and sponges
are mixed therewith, and we have a continuation, under our eyes, of what
was begun thousands of years ago.
Let us for a moment consider this fluid we call water, especially sea
water. Chemically speaking, pure water is one of the rarest things—that
is, water absolutely free from all foreign matter, divested of everything
save hydrogen and oxygen in the combining proportions, by weight one
part of hydrogen to eight of oxygen; by volume, two of hydrogen to one
of oxygen, we have pure water—an _oxide_ of _hydrogen_. But absolutely
pure water must be prepared in a vacuum, and it must never have contact
with air of any kind. Pure water would be instantly fatal to any animal
that had to breathe it with gills, as a fish, simply because it contains
no oxygen in solution, which the animal can use to oxydize the blood in
the gills. We in breathing air get oxygen by decomposing the air, but
animals that breathe in water do not decompose the water, but take from
it the free oxygen that is found mechanically mixed with the water. Pure
water, being the standard of measurement of liquors and solids, is taken
as one or one thousand. Sea water is 1,020, or near, whilst the water of
the Dead Sea, or of lakes and seas with no outlet go as high as 1,225, or
even to a point where they are saturated, or can not dissolve any more.
Such is the case with the Great Salt Lake of Utah, and Mono Lake, of
California. Water of this kind is not usually inhabited by any kind of
gill breathing animals.
How did the sea become salt? By the washings out of the land, and
the disintegration of the rocks by the elements, such as ice, wind,
heat, rain, etc. The sun causes evaporation; so that the sea is being
constantly lifted into the air and carried in the shape of clouds to the
land, where it is drawn down and flows again into the sea. The solid
matter carried down to the sea does not return. It remains in solution,
or is deposited on the bottom. The clouds contain almost pure water. They
distribute the visible ocean throughout the invisible air. The rocks and
the trees, the animals and the air all receive their respective shares
of water; and in the course of time it is returned to the sea. Were
evaporation to continue at the present rate, it would require about 1,600
years before the ocean beds would become dry land. But in one way and
another there is just as much water returned to the sea each year as is
taken out. Not one drop is lost. The seas may change their beds—they may
flow where the forest now stands, and their waters may cover our highest
mountains, and their bottoms may rise many hundred feet above their
present level, and still there will not be one drop more or less of the
great body of water that now covers more than two-thirds of the earth’s
surface. The sea will still claim its own. The water that floats to-day
in the clouds may to-morrow course through some giant tree of the forest,
or be taken up in forming a beautiful crystal, or aid in the bloom and
fragrance of a flower, or be taken into the lungs of some animal and
deprived of the oxygen that it holds in solution, or it may be converted
into steam and propel a ship or a railroad train, or it may be buried
under the earth in a bed of coal and only be set free some thousands
of years hence. But like a wayward child it will return again to its
mother—the sea.
“Tho’ the mills of God grind slowly,
Yet they grind exceeding small;
Tho’ with patience He stands waiting,
With exactness grinds He all.”
The deliberation, the minuteness, the exactness, the patience and the
waiting of the grinding sea, and yet the magnificent, sublime result, are
most beautifully exemplified to those who have “entered into the springs
of the sea,” or have “walked in search of the depth.”
The upper currents of the sea are comparatively shallow. Whilst the depth
is often eight or nine miles, these currents in the deepest places do not
extend more than 2,000 or 3,000 feet, and usually only a few fathoms.
They move, however, when deep, with considerable velocity, say at the
rate of four miles an hour. The great body of water lies below, totally
undisturbed by any atmospheric agencies, yet moving slowly, invisibly,
but sufficient to keep the equilibrium and level of the waters. So
quietly does this great mass of the ocean pass over the bottom surface,
that the smallest particle of microscopic matter that has fallen down, is
not disturbed, and would remain there forever, but for the giant tread of
the earthquake, or the volcanic explosion. The dust ground and deposited
by the “mills of God,” makes the foundations of islands and continents.
Although demonstrated that life organisms extend to the bottom at the
deepest places, yet in the rapidly flowing current the busy activities of
life are to be seen. There are plains and meadows, forests and deserts,
hills, mountains and plateaus, in the sea. At some places the bottom
teems with life. Take, for instance, what are called the “banks”—the
fishing grounds of Norway, Ireland, Newfoundland, etc.; they are
submarine plains unquestionably, and must have a high degree of fertility
in order to supply food for the billions of fish of a voracious kind—as
codfish, halibut, etc. These large fish feed on mollusca and crustacea,
and these feed on smaller animals—but principally on Algæ or sea-weed.
Feeding on pastures of this kind we sometimes find the most enormous
animals. Steller’s sea-cow is an instance. They are described as found by
him in 1742, on Behring’s Island, covered with a hide resembling the bark
of an old oak tree. They grew to be thirty-five or forty feet long, and
to weigh 50,000 pounds. They fed on the abundant Algæ along the coast.
They yielded milk in abundance, which with their flesh were said by
Steller to be superior to those of the cow.
But if the sea map be considered as an aquarium, (that is, a body of
water supporting animal and vegetable life), better expressed by the term
_aquavivarium_—so may it be considered a cemetery, an _aquamortuum_. The
life, so profuse, that takes into itself bodies of endless forms and
sizes, finally yields them up to the sea, and they are buried in the
bottom. There is no land where the sea has not been, and where “vestiges
of creation” may not be found. If we ascend to the highest mountain,
or descend to the lowest valley, behold there are diatoms, shells of
mollusks, débris of corals, and bones of whales. Whence came they?
Science can answer no better than Scripture: “The earth is the Lord’s,
and the fulness thereof; the world and they that dwell therein. For He
hath founded it upon the seas and established it upon the floods.”
Beside the natural course of life and death, there are various ways by
which the inhabitants of the sea may be suddenly destroyed. As, for
instance: by the influx of fresh water; by volcanic agency; by earthquake
waves; by storms; by suffocation when crowded into shoals, weeds, sand,
etc.; being driven ashore by fishes of prey; too much or too little heat;
diseases and parasites; poisons; lightning; and many other agencies.
Although the sea is immense, it has bounds and limits; thus far and
no farther, is the command of Him that made it. I am overpowered with
the immensity of the subject. In trying to comprehend the whole it is
impossible to see the minutia; or to compass within our limits one fairly
developed idea.
I think, however, we have arrived at a point of knowledge where we may
answer an oft repeated question: “Why the Almighty has created so many
insects, covering the earth, swarming in the air, or teeming in the
waters?” They doubtless have many purposes, that in our dim knowledge we
do not see, but they serve at least one important end; they are carbon
makers, and without carbon no plant can grow, and without the plant what
would become of the animal? So, to a certain extent our lives depend on
the things which ofttimes only seem to annoy us. We are so ground in
the mills of God, so built, linked and woven, so dependent and so cared
for by the power that is in us, that the microscope can see nothing too
small, that does not concern us in its use and sphere of action; and the
telescope can behold no world so grand but it, too, may be considered
only an aggregated expression of what we find in the miniature object.
No organism that lives and dies in the sea is lost or wasted, and
like the drops of water that are scattered and spread abroad over the
universe, and are gathered again to the sea, so do all these forms of
life that inhabit the deep serve an important purpose while living, and
when the life has departed from their forms they leave their good works
behind them in the shape of iron, lime, silica, and carbon, for the use
and the convenience of other lives that succeed them.