The Jersey City news. (Jersey City [N.J.]) 1889-1906, 1896-07-31
OCEAN CURRENTS.
The U. S. photographic
Office Preparing a
New Chart.
COURSE DETERMINED BY BOTTLES
Velocity OF Drift Diminishes After
Leaving the Equator-Points
for Mariners.
COURSE DETERMINED BY BOTTLES

WASHINGTON. DC, July 81, 1ssS.-The
latest accessions to our 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 ninety-fve floating
bottles returned to that Office in the six
months ending June /. For several years
these Investigations have been carried on
through the in~strumentality of strong
Indian-elub shaped bottles OF special de-
sign bearing Government marks which
are distributed to shipmasters to be set
adrift at various points at sea, with data
papers to be properly fllsd in and sealed
in the bottle. These papers in a great pro-
portion OF instances are returned to the
/ Naval Hydrographer, with memoranda
giving the time and place Of rescue, and
the probable course is then charted and
made the subject Of expert study. In the
case of the ninety-hve papers most re-
Gently returned the courses taken coilec-
lively serve to clearly illustrate The two
main features of the general surface cir
c~ulation Of the waters Of the North At
lantic, the first being a vast but gentle
eddy, extending from the equator on the
south to the parallel of IS degrees on the
north, and completely enclosing that por-
ton of the ocean lying between the trades
and the anti-trades, the region of the Sar-
gasso Sea, in which the currents are
feeble in force and variable in direction;
the second being the so-ealled extension
OF the Gulf Stream. which leaves the
northern limits of the main drift in the
neighborhood OF 80 degrees west and pro-
ceeding northeastward skirts the shores
of Iceland or the one hand, Scotland n
Norway on the other.
1t appears from the chart that bottles
cast away along the United States coast
invariably sweep eastward, some dropping
on the Azores. others passing to the Cam
aries and those avoiding these islands
eventually drift south and west across
the ocean to be found on the Windward
or Caribbee Islands or Mexican Gulf
beaches.
Those dropped overheard along the
Nova Seotian coast and the Grand Banks
appear to make a direct northwest voy-
half Of those commencing their Wander
fngs on the Equator In mid-oeean go
south along the BRAZILIAN coast and the
half enter the Caribbean Sea. The great
journey on the new chart was that Of
Bottle No.. s. thrown overheard By the
master of the Steamer Enoch in the midst
OF the Guinea current. which ordinarily
sets eastward towards the coastof Africa
and into the Gulf Of Guinea. This yoy-
age began below the Equator a thous-
and miles off Sierra Leone on July 30,
Totabrough Walls. Shetland Islands.
March %, 1895, after having travelled
nearly 5000 in 963 days across the ocean
through the Caribbean Sea. the Gulf of
Mexico, the Gulf Stream and over the
with an average gift of over eight miles
II summing up the velocities of drift
a steady diminution is apparent after
leaving the equator. The group of bottles
furnish knowledge of currents averaging
from seven to fifteen miles per day. One
of the important conclusions reached in
this latest investigation is the great in
crease of velocity during the winter sea-
son from Newfoundland toward Great
Britain and Norway, which seems not to
be continuous, but dependent largely upon
the winds, bottles in summer averaging
about ten miles per day, while one In win
ter maintained nearly twenty-five miles
per day for ninety-four days in this cur
rent. In the great circular sweep around
the Sargasso Sea the chart shows In dot
ted lines the drift of the three derelicts,
the schooner Unexpected the schooner
"E. H. Cornell" and the schooner Alma
Cummings, all of which hoated with
desks awash for nan months The path
iiy 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 are 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 man. others 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
southwark until the meridian of 40 de-
grees is approximately attained.