Weekly national intelligencer. [volume] (Washington [D.C.]) 1841-1869, 1848-12-30
MAURY's WIND AND CURRENT CHART.
FROM THE JOURNAL OF COMMERCE.

Practical navigation is deriving the greatest bene-
hts from the developments made by Lieut.. MAURY
III relation to the course and velocity Of currents
and the direction and strength of winds. The i'm
poIant results already attained encourage the hope that
distant day, the duration Of voyages in sailing ships may
be calculated with precision almost great in vessels
propelled by steam and that the occurrence Of and
the direction of winds any given route may be anticipated
thus enabling the sailor lay his avoid alike
the tempest and the calm and guided the light Of science
to reach his destined port in safety and with speed In the
practical application Of meteorological discoveries and
of the truths of geomeca science the purposes of nav
cation, Lieut. Maury has essentially subserved the interests
not alone Of commerce. but Of humanity and deserves
ranked among the benefactors of his kind The ingenious
method devised by him to record Of facts falling with
in the observation Of mariners by the Abstract Log, has
proved than adequate the purposes which de-
signed accomplish and has supplied Of
varied nformaton which has suggested extension Of the
plan of the work since the numbers comprising the North
Atlantic ocean were issued.
Lieut. M intends construct charts of the three grea
after the plan of the Rio Sheet and accompany the
whole with what is called Pilot Chart specimen Of which
for August and September is before The Pilot Chart
constructed thus Lieut. M. has many tracks than tie
chart will hold even in coors but to give the practical nj,
vgaor the benefit of the experience of all Of them has
divided the out into sections of 50 degrees squares that
is each section contains 50 of latitude and 50 of longitude
For the sake Of ustraon take that section between 25o and
800 west from the equator and 50 NORTH He has the tracks
OF several thousand vessels this section Suppose that
five hundred of them in the month OF August the drec
ton of the wind, each Of these five hundred found
entered in its appropriate column his manuscript chart
and when the whole gone through with the result is en-
tered compass drawn in this section so as to show at
glance the number of Gains, the number ofwnds from the
north, from norh-nqrtheas, northeast, and on, for
every two points around the compass The done for
every month and for every section Of 50 square the
| whole ocean.
Now, suppose that vessel with this Pilot Chart wants to
make south through this section in August Cor any
month"; but suppose for August the captain consus his
Pilot Chart to what his chances for head winds and
are, and what chances for fair winds Out Of the five
hundred entries he finds that there twenty calm that the
winds two hundred and fifty times from southeast twenty
from south southeast, from south, six from southsouh
west, four from southwest and two from wessouhwest and
Of hundred and eighty EIGHT from all other points
His chances them of fair wind from south would
be only hundred and ninety out of FIVE hundredodds
| against him nearly as five to two.
He looks to how the chances would be for south
southwest The hundred and fifty southeast
winds fair winds for this course and the chances Of a
wind for this would be four hundred and y-egh out
Of five hundred-odds greatly in his favor nearly twelve ia
one He would then, in approaching this section, aim
make it where south-souhwest would be good
and Of any other section any month.
Thus with the Pilot Chart, each navigator before sailing
could lay off the which would give him the mos
chances for fair winds This Pilot Chart Of course
be finished until the whole is completed, until its author
gets tracks enough through any section enable him to
rive at the fair average Of winds from each point during any
month.