Daily camera., 1901-09-24
TRACING THE TIDES.
Interesting Experiments Conducted
BY Government 0facials.
Valuable Facts Revealed by the Use
Of Fleatiag Bottles Set A1rtft In
the Oooan-Assn8s of the
Walk

d FIOotAo8 0Ottleo ser AOtlxS II
the 0esan-Rssa1s ef the
Work.
There are several thousand com
mon beer bottles floating about In
the northern Atlantic and Pacific
ocean, drifting with the currents, in
the interest of science. The pur
pose Il to determine the drift OF
bodies coming under the influence OF
the currents Of the ocean. Thousands
OF these bottles, containing minute
descriptions printed In seven differ
ent languages. are annually thrown
into the sea under the supervision OF
the navy department. with the ex-
pectation that many win be found BY
passing vessels, their location noted
and the fact reported to Washing
ton. says . recent report.
Each bottle contains q written d.
rection ~ to what shall be done by
the skipper who finds it. He IL sup
posed to note the latitude and longi.
tude where It was found, where il
was thrown into the sea, and the
probable distance travelled since IL
was originally thrown overheard.
Reports received at the navy de-
partment for the last fscal year in.
dicste that much valuable informa-
tion IL being gained BY this method
Recent reports present some re-
markabls drifts of bottles, several
having gone ~ far - the distance
across the ocean and one double that
distance. They vary from only . few
miles to over IS . day, which 10 al
most the average Of the usual dere-
lict exposed to the wind and often
borne along rapidly BY the small por-
tion Of woodwork above water serv-
ing - . catch for the breezes. One
bottle has the record of 900 miles
traverssd In ss7 days 1t the average
rate Of seven and one-half miles q
day. This bottle was thrown over
board from the ship Comliebank. OF
the Spanish merchant service; an
other drtfted 5000 miles in 6oA days.
at the average Of i've and one-half
miles . day. while . third Travelled
5000 miles In A7s days.
The most remarkable drift of all,
however, WAS that Of . bottle that
went 70 miles In two days. or at the
rate Of IS miles . day. Another trav-
eled 800 miles In eight days. At the
rate Of 2s.s milss day. while still
another 3.loo miles In lo+ days. At the
rate Of 10 miles . day. The latter
shows the quickest drift for long
distance Of any bottle reported.
Long-distance drifting In the Pa
eihc Is especially noticeable in the re-
ports received here. March ~. 1897.
bottle was tossed into the sea
from the ship Roekhurst. and.
after drifting for 7%s days. was
picked up. having covered in q
direct line s.ioo miles. or the
entire distance from San Francisco
to China. Its average rate was 30
knobs . day. Another bottle thrown
into the sea from the spaaish ship Bel
mont on QctobSs 10. 1896. and report
ed June -. 1899. Travelled 1900 miles
in the interval At the rate Of ~ knots .
day. Still another thrown ipto the -.
September, 1898. and reported II
months after, had tailed $500 miles a,
the rate Of ia-a knots . day. The mum.
Der OF bottles picked up and investi-
gated iuerssses each year.
The main features indicated in the
drifts are that bottles thrown into the
sea near the equatorial and trade wind
region tend to the westward and usu-
ally bring up in the West Indies. or ON
the AsxicAA ooast. Along the Amer
lean coast. north Of the fortieth par
sllel. these conditions are reversed.
Here the general direction of the wa
tiers il to the northward and eastward.
and bottles thrown into the North At
lsn;ic And their way to tAe north coast
Of Ireland. or farther North.
Between tAeis two main drifts. and
occupying . stretch Of ocean extend
Ing in latitude from IS degrees north
10 20 degrees north. and In longitude
from 30 degrees west to 60 degrees
west. Hes debatabis region crossed
BY numerous steamship and sailing
routes. and within which many bot
ties are cast 10 determine the drift Of
the waters. The recovery of such bot
ties Is rare. and the records Of the hy-
drogfapAic oiace show but six bottles
recovered from this seotioa aimee 1858.
The average velocity daily of the
70 hottlsA which landed ON the coast
Of Europe was I'VE miles. The bot
ties which driftsd entirely across the
ocean from west TO east unite in civ
ing An average somewh higher than
usual. the last two having Travelled
ia miles and 90 miles per day, re-
spectively. For those thrown over.
board in the north equstorial drift the
average was 1913 miles . day, while
those travelling along the north coast
OF South America averaged 81 miles a
DAY. A chart Of the North Atlantic
shows hundreds Of bottles drifting
about the ocean. which nay some time
be reported By ships crossing the seas.
v A. ~