Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1892-04-10

sea bottom; which goes to show that sci
entifc men cannot always, with safety, at
tribute to mighty phenomena the accidental
finds they make.
The map shows the wonderful interest the
world is now taking in deep sea explora-
ton. The science of oceanography is still
young and. strangely enough, it was not
naturalists but engineers who first began to
explore the ocean depths. 1t was when the
first submarine cable between Europe and
America was laid that the scientific world
turned its attention to the study of the
ocean abysms. The English vessel Porcu-
pine, in 1869, fairly ushered in the era of
deep sea research. Then followed the
memorable expedition of the Challenger in
1872, and later came crowd Of investiga-
tions in every sea.
The Ocean Bed Is n Plain.
1t may be said that in their broader feat
ures the contour of the ocean bed and the
phase of deep sea life are now revealed.
Here are some of the most interesting facts
that have been learned:
It was supposed few years ago that the
ocean bottom was largely counterpart of
the land features of the globe, with its
mighty mountain ranges pushing up toward
the surface of the sea, and deep valleys and
glens sinking to almost untathomable
depths This is found to be true only to
limited extent. Here and there, to be sure,
mighty mountains push toward the surface
or rise above it, forming islands; and then
again the bottom sinks in q narrow trough,
as off the northeast coast of Japan, until it
seems as though the sounding line could
never measure its depth. But the ocean
bed, in the main, is found gently to undu-
late, and would present the appearance, if
it could be observed, of a slightly rolling
plain.
1t has been found also that we used to
depths Maury, in his day the great au-
thority upon the ocean, popularized the
idea that depth of eight or nine miles
might be found in mid-ocean. We know
now that a depth of five miles is very ex-
ceptional. General Won Tillo, who has
made the latest determinations of ocean
depths, fixes the mean depth of all oceans
at 8, ,S03 metres, or about 12, 700 feet, less
than two-and-a-half miles. The Pacific
Ocean averages about ], 100 feet deeper than
the Atlantic. The North Atlantic is deeper
than the Southern Atlantic, and Arctic
Ocean grows shallower the nearer the pole
is approached.
deposits From Rivers and Icebergs.
Very interesting facts have been discov-
cred with regard to the great distances from
land at which the sediment brought down
by mighty rivers is spread over the sea bot
tom. Those giants among rivers, the Niger
and Congo, produce most marked effects
upon the nature of the deposits at the bot
tom of the ocean. Buchanan has found that
the sea bed for hundreds of miles from land,
from the Gulf of Guinea to Loanda, has
been filled up to an enormous extent by the
dark-colored soft muds brought down by
the rivers; and off the mouth of the Congo
the shore mud has been traced to depth of
$1,000 feet at distance of 600 miles from
land. In the Bay OF Bengal and the Ara
bian Sea the sediment from the Indus and
the Ganges is spie cad out over the greater
extent of the oceans floor. Antartic ice
brings as far north as 400 south latitude the
debris from lands perhaps still unknown.
DR.. Murray says, however, that toward the
central parts of the oceans it is difficult to
trace the ordinary river detritus in the de-
posits there forming.
Before the Challenger expedition only
six deep sea fishes were known. To-day
about ten times as many forms of deep sea
life are familiar to oceanographers. We
can form some idea of the abundance of life
existing in some regions at a depth of 2X
miles, when it is said that at single haul
of the trawl only II feet wide and dragged
over the bottom for very short distance,
as many as $50 specimens of the higher
forms of deep sea life have been obtained.
TYo Kinds of Oceanic Life.
One very interesting fact seems to have
been established by the recent investigations
in the Pacific of our Fish Commission steamer
Albatross. 1t has long been known that
the group of animals characteristic of the
upper part of oceanic waters is entirely dis
tinct from the forms of life near, and at the
bottom of the sea The Challenger in
vestigators thought they had established the
fact that another distinct group Of animals
exists in the intermediate depths between
these upper and lower forms Of life. This