The Hawaiian gazette., 1869-01-13

The BoTToM OF THE OcEAS.--In 1858,
mud was obtained by Lieut.. Brooke, from
the bottom of the Atlantic, between New
Foundland and the Azores, at a depth of
more than 10000 feet, or two miles, by the
help of his sounding apparatus. The speci-
mems were sent for examination TO Ehren-
berg, Of Berlin, and to Bailey, of West Point,
and those able microscopists found that this
deep sea mud was almost entirely composed
of the skeletons of living organism, the great
er proportions of those being just like the
globigeran@ already known TO occur In chalk.
Thus far, the work had been carried on sim
ply in the interest of science; but Lieut.
Brooke's method of sounding acquired high
commercial value when the enterprise Of lay
ing down the telegraph cable between Great
Britain and the United States was undertak-
en-; for IL became q matter of immense i'm
portance TO know, not only the depth of the
sea over the whole line along which the cable
was TO be laid, but the exact nature Of the
bottom, so as TO guard against the chances of
cutting or fraying the strands of that costly
rope. The Admiralty consequently ordered
Captain Dayman to ascertain the depth of the
whole line Of the cable, and to bring back
specimens of the bottom. In former days,
such a command as his might have sounded
very much like one of the impossible things
which the young prince in the fairy tales Is
ordered TO do before he can obtain the hand
OF the princess. However, in the months of
june and July. 1s47 Captain Dayman per-
formed the task assigned TO him with great
precision, without, SO far as know, having
met any reward of that kind. The speci-
mems of Atlantic mud which he procured,
were sent to me to be examined and reported
upon. The result of all these operations is,
that we know the contours and nature of
the suriace-soil covered by the North Allan
tic for a distance of 100 miles from east TO
west, as well as We know that of any part of
the dry land. 1t is prodigiOus plain, one of
the widest and most even plains In the world.
II The sea were drained off, you might drive
a wagon all the way from Valentia, on the
west coast of Ireland, to Trinity Bay. in New
Foundland And, except upon one sharp in-
cline about 200 miles from Valentia, am
not quite sure that it would even be necessa-
ry to put the skid on, SO gentle are the as
cents and descents upon that long route.
From Valentia the road would be down hill
for about 200 miles to the point where the
bottom is now covered by 100 fathoms of
sea water. Then would come the central
plain, more than 1000 miles wide, the inequal
ity of which would be hardly perceptible,
though the depth of water upon IL varies
from 10, 900 to 1900 feet; and there are places
in which Mount Blanc might be sunk with
out showing its peak above water. Beyond
this, the ascent on the American side com
mences and gradually leads for about 800
miles, TO the New Foundland shore. Almost
the whole of the bottom of this central plain
(Which extends many hundred miles in q
north and south direction) is covered by q
fine mud, which, when brought TO the sur
face, dries into grayish-whte friable SUBJ
stance. You can write with this on black
board, if you are so inclined, and to the eye
it is quite like very soft, grayish chalk. Ex-
amined chemically, IL proved to be composed
almost wholly of carbonate of lime; and if
you make a section of it in the same way as
that of piece of chalk is made, and view it
with the microscope, it presents innumerable
globigerne, embedded in the granular mat
rix. Thus this deep sea mud is substantially
chalk / say substantially, because there are
great many minor differences; but as these
have no bearing upon the question imme-
diately before us-which is the nature of the
globierne of the chalk-it is unnecessary to
speak of them.-Rrof. Hahley.