The Lambertville record. [volume] (Lambertville, N.J.) 1872-1968, 1872-09-24
NEITHER PROBABILITIES At W-dsH-
INGTON.


The following is condensed account of the
manner in which the observations are made
over the country, and the calculation of the
probabilities for the next day are made at
Washington:
There are SO signal stations in the United
States, the extreme outposts being Portland,
Maine; Key West, Florida, Galveston, San
Diego, Portland, Oregon, and Duluth. Each
station is furnished with a barometer, ther-
mometer, hygrometer, windvane, lain-gaugc,
anemometer and clock.
The barometer is the Green's standard, and
is always carefully compared with the STAN
dard office before issue for use. 1t is placed
in room of uniform temperature, not heated
or too much exposed to the sun. When not
in use, the cover is kept closed. When an
observation is taken it is opened, and the bar
ometer slipped back into the box.
The thermometer is hung at height of the
eye, in the open air, facing the north in such
a manner that it is always in the shade. 1t is
placed so as to avoid the light reflected from
surrounding objects, and protected from rain,
snow, and hail.
The hygrometer is an instrument used in de-
tennining the degree of moisture in the at
mosphere. 1t is placed in the same shelter as
the thermometer, and near it.
The thermometer is an instrument used to
measure the force and velocity of the wind.
1t is composed of little saucers travelling
around perpendicular bar, each after the
other, like dog trying to catch his TAIL The
thermometer is fixed in a vertical position upon
post of sufficient height to bring it ON a level
with the observer, and must be in an exposed
position, so as to receive the full force of the
wind.
The aciRd-oaae is worked on the same prin-
ciple as are weathercocks. It is, however, of
scientific construction, and by means of
dial at the base, gives with great exactness
the direction of the wind in any point of
the compass.
The rain-gauge is placed with the top of
the funnel-shaped collector a foot above the
surface of the ground, firmly fixed in verti-
cal position. 1t examined daily the amount
of water it contains carefully measured with
a graduated rod, emptied, and again fixed in
place. The clock which is a good one, keeps
Washington time.
With these Instruments, none of which are
complicated, the humidity of the atmosphere,
force, velocity and direction of the wind, attest
of the thermometer, and all particulars about
the weather, including the inches of rainfall,
are ascertaincd in every part of the United
States.
y Observations are made ut the several sta
lions three times each twenty-four hours,
morning, evening and midnight. As the
clocks are all set by Washington time in each
of the sixty-two stations, all the observations
are taken at the same instant. BY II y. M,
everything being ready at the telegraph office,
a wire on each circuit is surrendered by the
telegraph company for about ten minutes and
the reports come rafting ill., In about 40
minutes from the time they commence COM
inc they are all received when they are mark
ed on a map of the United States. The state
of the barometer, thermometer direction of
the winds, &C., &C., over the whole country
are seen at u glance and upon this as a basis,
the eprobabilities" for the next twenty-four
hours are calculated. The reports are received,
translated set up for the map, maps litho-
graphed and printed, and ready for distribu-
ton, and the whole report in course of trans
mission over the country within an hour.
The Signal Office is making arrangements
for obtaining information interesting to agri-
culturists Several new features have recent
ly been introduced by Gen. Meyer, the chief
signal officer, among them the appearance of
the sunset, which is obtained by means of
convex mirror, the colors and shades being
traced with pastels on plane of glass placed
above the mirror In this manner the APP
pearance and forms of clouds are also noted
with correctness and facility. The visitor is
Interested in miniature representations of
clouds and their movements under certain con-
ditons of the atmosphere, the materials en-
ploycd for this purpose being merely wire and
raw cotton Every branch of the office is
under strict discipline, and all engaged in its
administration seem to be influenced by de-
sire to further promote its uscfulness.-Ob-