The circle banner. [volume] (Circle, Mont.) 1914-1939, 1924-07-11
SAFETY OF SHIPS
UP TO U. S. AGENCY
Work of Coast and Geodetic
Survey Outlined

the Leyiathan and the Majestic,
show how essential to the safety OF
the worlds shipping is an intimate
knowledge of the complicated tidal and
current fluctuations of the worlds
great harbors," says bulletin of the
National Geographic society, issued
from Its Washington ID. CO., head
quarters, 'and emphasizes the impor-
lance of one of the phases of the work
of the United States coast and geodetic
survey.
New York harbor is not single
waterway, but series Of communicate
ing ones, with two entrances from the
sea. A territory larger than Massa-
chusetts,5 Connecticut and Rhode Island
together, drains into the Atlantic
through three bays, four straits, and
one great and several small tidal riv-
ers The fresh water from this large
area complexities the problem of Civ
ing the navigator definite data as TO
flood and ebb and current so that he
may safely maneuver his craft at all
times.
"The United States coast and geo
detic survey has given nayigators a
definite picture of the conditions they
must meet in .berthing their great
liners to wharf engineers the infor-
nation necessary to the proper ar
rangement Of docking facilities; and
to sanitary engineers new and basic
data that has an important bearing on
the problem of sewage disposal.
working quietly on the great fun
damental problems of navigation, the
coast and geodetic survey doesn't
make much copy, and the world al
large hears comparatively little of one
of the most highly technical of the
scientific bureaus of the United States
government.
"And yet every ship that sails the
seas, every passenger that comes into
port, every article on the supercargo's
manifest are served In a very con-
crete, it unsupported. way by the
survey.
1.-TWO things the navigator must
have If he Is to bring his craft with
it's human and material cargo safely
into port-a knowledge of the tricks
Of the compass and picture Of chan
mel and harbor conditions.
Vaaaries of a Compass Needle.
"The needle of the mariners COM
pass has been shown to be as full of
vagaries as mid-March weather. Men
used to think that 1t could always be
depended upon to point to the mag
netic pole. But local affinities dis
tract 1t from It's proper affection in
ways that are sometimes startling. If
the sailor has a sweetheart in every
port, the magnetic needle has secon-
dairy attraction in many quarters.
Looking at a magnetic declinatlon
chart we see deeply waved curves
which proclaim loudly the influence OF
these affinities in weaving the needle
away from the straight and narrow
of its true direction. Magnetic sur
veys on the sea in general and along
the coast In particular, are supreme
necessity In the accurate guidance of
ships over the trackless ocean and into
the worlds ports.
Examining the line of the Is degree
west declination we find 1t sweeping
over the sea in q northwesterly direc-
ton, with comparatively small varia-
lions from normally until 1t ap-
proaches the north shore Of Massa-
chusetts. There it swings radically to
the west and as land Is reached |
swings back until 1t points almost due /
northeast at more than right angle |
to its recent position as it rounds the
Cape Ann peninsula.
Goes on Spree In New York.
1.-The same condition obtains In the
10 degree west declination which |
sweeps over the Atlantic toward New |
York. Approaching the waters be-
tween Long Island and Sandy Hook
the needle adheres closely to It's proper
direction. But when it reaches the
Hudson river it is pulled around until
it seems to forget all about Its funda-
mental affection and goes on a lark
that causes 1t to swing around through
almost or quite quarter circle from
Its accustomed position.
''No wonder q magnetic survey Is
needed to warn the mariner of the
yagarfes of the magnetic needle when
1t permits itself to fall so fully under
the spell of the Great White way that
it wanders 90 degrees away from It's
path of solar duty.
1.-The need of more thorough sound
ings In harbors and on rocky coasts
grows greater as the volume and COM
plexity of shipping grows and the size
Of craft increases.
"Soundings made with lead lines can
be depended on to discover the main
underwater elevations, but the waters
off the New England shores, the Pa
cific shores and Alaska abound In pin
nacle Washington monuments
of the sea. They rise to sharp points
almost to the surface, which defect a
lead line, even though the lead may,
on slender chance, land on top of
them.
Thus 1t came to be that they passed
undiscovered and uncharted until some