The evening times., 1896-07-31

The latest accessions to knowledge OF
ocean currents is set forth in a chart to be
published in a few days by the United
States photographic Office. mapping the
routes followed by s5 floating bottles re-
turned to that Office in the SIX months
ending June /.
For several years these Investigations
have been carried on through the instru-
mentality or strong, Indian club shaped
bottles OF special design, bearing gov
eminent marks, which are distributed TO
ship masters to be set adrift at various
points at sea, with data papers. to be
properly filled in and sealed in the bottle.
These papers, in gleat proportion Of
instances, are returned TO tie naval hydro
grapher with nenCraBua, giving the TINE
and place of rescae, and the probable course
is theD oharted and made the subject OF
expert study.
III the ca of the ninety five papers, most
recently returned, the courses taken col
lectiyely serves 10 clearly Illustrate the Two
main features of the gene raj sur face circula-
ton OF the writers OF the North Atlantic.
A VAST EDDY.
The first is vast but gentle eddy, ex-
tending FROM the equator on the south, to
the parallel Of As degrees Oh the north, and
completely enclosing that portion of the
ocean lying between The trades and the
anti-tr rades, the region of the Sar gasso Sea,
IN which the currents are ieeb;e in force
and variable in direction.
The second is the so-cailed extension of
the Gulf Stream, which leaves the north
ern limits Of the main drift in the neigh
borhood of 80 degrees west, and pro-
cceding northeast, skirts the shores of
Iceland on the one hand, aud Scotland and
Norway on the other
Itappears from the chart that bottles cast
away along the United States coast in
varably sweep eastward, some dropping on
the Azores, others passing to the Canaries.
ana those avoiding these islands eventually
diff south and west, across the ocean TO
be found on the Winward or Caribbee Is
lands or Mexican Gulf beaches.
Those dropped overheard along the Nova
Sootlan Coast and the Grand Banks appear
10 make Al direct northeast voyage to the
British Isles and Norway, while half of those
commencing their wandcrngs ON the equa-
tor In inidOcean, go south along the Bra
- lillian coast, and the other half enter the
Caribbean Sea.
TRAVELLED 5000 MILES.
The greatest journey on the new chart
was that of bottle No. u. thrown overheard
by the master of the steamer Enoch, in the
midst OF the Guinea current which orui.
nariiy sets eastward, toward the coast of
Africa and into The Gulf uf Guinea.
This voyage began below the equator, O
Thousand miles off Sierra Leone on July
so, 1898, ard the bottle was recovered at
Totabrough Walls, Shetland Islands, March
2, 1886. after having Travelled nearly
= S,00o miles in S63 days across the ocean
through the Caribbean Sea, tie Gulf OF
Mexico. the Gulf Stream and over the Grand
Banks, recrossing the Atlantic with an
average drift of over eighteen miles per
day.
In summing up the velocities OF drift
steady diminution is apparent after leay-
ing the equator. The groups CT Eott!es fur
nish knowledge of currents averaging from
seven 10 fifteen miles per day. One of the
important conclusions reached in this latest
inves tigauon is the great increase in
velocity.
During the winter season, from New
foundland toward Great Britain and Nor
way, which seems not TO tie continuous,
but dependent largely upon the winds,
bottles In summer average about ter
miles per day, while one in winter MUM
tained nearly twenty-five miles per day for
niDcty-four days in this current.
In the great circular sweep around the
kargasso Sea the chart shows in dotted
lines the drift of the three derelicts, the
schooner Unexpected. the steamer L. H.
Cornell and the schooner Alma Cummings,
all OF which flolted with decks aswash.
The path followed by drifting bottle
Ia necessarily uncertain, inasmuch as but
two points in its course are determined: the
path followed by the floating derelicts is
not open TO this objection. as they Ire OBJ
served from time to time by passing YES
sells, their position duly reported to the
photographic office and marked upon the
pilot charts.
The drift of these derelicts, and OF many
Others, shown from month to month upon the
pilot chart. renders it probable that the
easteriy drift in the Central North Atlantic
does not tend to the southward until the
meridian OF 40 degrees is approximately
attained.