The daily dispatch. [volume] (Richmond [Va.]) 1850-1884, 1880-11-19

FALL MELTING or THE NATIONAL ACApEMr-
| TuE CRUISE OF THE BLAKs LAST SUMNER
| GIGANTIC PLATEAU TRAvERssD BY THE GULF
| STREAM.
| New York Times ]
| The regular fall meeting Of the National
Academy OF Sciences opened at IL o'clock
yesterday In the Greek room Of the new
academic building at Columbian College.
The November meeting Is always devoted
purely to the reading OF papers on scientific
subjects aud 10 the discussion OF scientific
questions.
The 6rst paper on the list was that Of
Professor Agassiz on the dredging cruise OF
the Blake, whose work has been spoken OF
in terms OF the highest compliment in re-
cent No. OF Nature. After giving some
details respecting the previous cruises OF
the Blake and the points intended TO he
elucidated by the several expeditions, Pro-
fcssor lsgassiz said tho results Obtained bad
shown that the deep.sea fiuna extended to
limit considerably higher than was for
merly supposed-namely. TO dcph OF
about $50 fa,homs. At about this depth lay
the outermcst limit OF another belt OF ami
NAL life, which he should style the conti-
mental fauna, aud which extended from a
depth OF about $50 feet 10 one OF 100 f,th-
omS. To observe exactly the connection
and relation 81 these fauDG 10 each other
was one Of the purposes Of the cruise
e the Bake lat summer. The coast
OF South Carolina was selected as
Il base Of operations, and the re-
gicn 10 be examined was laid out
in regular sections. The first procedure
was 10 run line south OF Cape Ha,teras In
an casierly direction another north OF Hat
teraS, and a third az Cape May. Each of
these lines began NJ depth Of about $50
fathoms. and extended completely across
the Gulf Stream. For distance OF $50
miles from The shore greater depth than
| $50 iatbOms OF water did not occur az any
point embraced In the survey, and there
was very little variation from general
average, thus showing that the Gulf stream
courses along nm immense plateau, when
was probably the original limit OF the con-
I tneni. The breadth OF this gigantic sub.
marine plain was from 100 to $50 miles. OF
| the coast Of South Carolina, at depth Of
about 100 faihomS, the margin OF IN abrupt
and very rapid declvity was found, and
/ then fol- some distance deep submarine
valley. After this Interval was crossed the
ascent was equally abrupt. The external
marein OF the stream has not yet been de-
tcrmined, but its general Typographical re-
larions are now pretty well understood.
! Professor AgissiZ next described the eX-
/ tcrnal margin OF this vast submarine plateau
and its extreme fertility in animal life. For
distance Of 80 miles of the South Carolina
shore our submarine explorers never car
Iied a depth OF more than 80 to 215
/ fathOmS but when The outer edge was once
arrived at the a5ruptness OF the descent
was somewhat startling. The ground fell
/ for the fist ships length after the declivity
commenced full 100 fathoms. and for three
shius' lengths $50, or $50 feet. II was
along this margin that the principal zcolog-
! icai interest cenIercd. The elevated plateau
Itself which adj0ined the shore was pract-
! cllly swept clear OF silt and mud by the
/ ever-res,leSs currents cOurSng over 1t;
+ but upon its extreme margin The deposit
was something enormous, ana the eXpedl-
ton found at The Outfall Of tn Gull
stream wealth Of marine life larger
! than at any point in the tropics. The shot
would sometimes sink FROM Is 10 20 feet
/ into the sIlmy mass. which had been cleaned
| from the level plateau 10y the action OF The
water. and here dropped in an enormous
drift which was peopled with submarine
fauna. OF course, owing 10 this freedom
! from silt, the plateau could not furnls0 1000
for any large development OF animal lie,
and il was consequently concentrated in
]
an interesting ted for Investigation. TIE
deposit did not appear tocmbrace any great
number of species, and was mainly remark
able for immense quantity rather than fer
variety or range. In summing up the re-
suits OF bis summers work ia CONNIE ction
with the Blake, Professor Agassiz re-
ported that the important point was
| the proof that The deep->ea fauna OF
the Atlantic bottom extended shore
ward to depth very considerably less
than had been heretofore supposed hy natu-
raIlsis. 1t bad been ascertaneG that II was
substantially identical with that OF the Gun
of Mexico, while the fauna II the west In
dian track was of the peculiar type he bad
STYLED continental. The current OF the Cur
stream being extremely strong, It's Track
was peculiarly barren IN forms OF amman
! life. and the extension Of the continental
! fauna from the West Indies north ward was
| 10 be sought only along the edge OF The PA
teau he had previously described. He would
allude. i'm conclusion, TO the great success
of the eXDedi'on. Their facility in dredg-
| Iug had be come something extraordinary by
| long practice, and the work they had been
able TO accomplish in six weeks was won
derful. When the Blake made her hrS'
cruise one haul day was considered pretty
active employment. The last day they were