The Fremont weekly journal. [volume] (Fremont, Sandusky County, Ohio) 1867-1877, 1872-06-21
From the Louisville Courier-Journal.
THE SIGNAL SERVICE.
How Storms and Tempests are Fore
told and Farmers and Sailors
Forearmed.

The creation of the Government
ISignal Service for obtaining weather
kilograms and for dispatching storm
warnings to the lake shores and sea
board, besides giving detailed ac
counts of the local atmospheric
changes, with the state of wind and
weather, as published in the neWspa-
pers in all parts or the country every
morning, is an enterprise of vast
moment. and after but few months
existence is now considered invalu
able to American commerce.
Signal offices for local observa-
tions and the transmission Of wealth
er kilograms have been established
in the various important cities
throughout the United States, stu
/ ated at such intervals as to enable
the various meteorological observers
to take cognizance of the atmospher-
ic changes in all sections of the coun-
try, and report to Washington the
, state of wind and weather from every
quarter, accurately foretelling the
approach of storms on land and tenn
pests at sea.
The signal service system was es-
tablished for the benefit of Ameri-
can commerce, and it contemplates
averting much of the destruction to
life and property upon the lakes and
seabOard; and observers being able
by the meteorological instruments
employed, to foretell the approach
! ing tempest tWenty-four hours in
advance Of its arrival at any given
point.
The Office established in this city
is situated in the fifth story of New
combs building en- the corner of
: Main and Bulitt Streets, and, as it is
as yet place that has been seldom
visited by the curiosity seekers of
the city, description of the instru-
,, ments employed may be of some int
crest to the reader.
THE INSTRUMENT SHELTER,
Projecting from the north window,
is scientific arrangement for the
exposure of the thermometer and
9 hygrometer. The roof is rain tight.
The sides are made of double lattice
work, sloping in and out like the let
ter A. This contrivance excludes
both the rayes of the sun in the
}, morning, and another infuence-not
it always considered-the indirect rays
of the sun, reflected from the sky OF
clouds or surrounding buildings
II The bottom of the shelter is left
open, its distance from the ground
being so considerable, that recitation
e from the latter is not appreciable
The instruments are fastened to the
verticle side of horizontal slat, mid
way between the window sash an6
north side of the shelter. They are
:. thus at least twelve inches from any
radiating surface. Connecting thi;
Sc consideration with the fact that the
instruments are the finest obtainable
o and adjusted to conform with the
standard at Washington, we art
iready to caution all people who
- "sling" thermometer, against the
= folly of requiring that the tempera
ture reported by the observer should
always coincide with their own. The
weather bureau, unfortunately hac
made no provision for furnishing
II sensational figures during Hcold
snaps" or the dog-days.
- THE HYGRoMETER,
Or humidity -guage, is also exposed
in the shelter. It consists simply Of
two thermometers hung upon one
v frame. The bulb of one thermometer
lis kept constantly moistened by a
cotton wick, the end of which is i'm
mersed in a small vessel Of water.
The water conveyed by capillary ac-
ition to the thermometer bulb, is
e evaporated by contact with the air,
: producing an artificial GOODNESS, and
making the temperature of the wet
bulb lower than the reading of the
bry bulb. In warm, clear, weather,
evaporation is greatest, and the diff
ference between the dry and wet bulb
most considerable.
Before wet weather, and during
/ cloudy and rainy weather, evapOra-
ton is least, and the readings of the
two bulbs more nearly conform.
When they exactly coincide, which
occurs during a dense fog, and some
times at the close of a protracted
rain, fhe "relative humidity" is said
to be 100 per cent. The temperature
of the wet bulb, and the difference
between the two bulbs being noted,
the humidity of the air is immediate
lily obtained from printed tublets ar
ranged for the purpose,
THE BAROMETER
lis conveniently hung upon the south
wall of the room. This instrument
lis the chief reliance of meteorolog-
list. That adopted by the Signal
IService ismade by Green of New
York. It consists primarily of al
glass cup, or cistern, and glass tube
closed at one end, and about three
feet long. Both cistern and tube
are filed with mercury. The tube,
after the air is expelled by heating,
is inverted and the open end proper
Iy secured, is immersed in the mer-
cury of the cistern. The mercury
| in the tube falls several inches, but
will preserve a moan hight of 30 in
ches, being sustained by the pressure
or weight of the air upon the surface
of the mercury in the cup. AS the
atmosphere increases or decreases IN
weight, grows fair or foul, the pres
sure will vary, and the column oil
mercury in the tube will rise or fall
correspondingly. This movement
is measured by scale divided into
inches and hundredths. The baro
meter readings at all stations are cal
culated for q temperature of thirty
two degrees, and additions made for
elevation above sea level. The
Louisville barometer, being five
hundred feet above tide water, re-
quires an additional correction of
about one-half inch. All improper
influences being thus eliminated, it
becomes possible to define the great
tracts of fair or wet weather, the
areas thigh ana low barometer men
toned in the probabilities" =
Ascending a pair of stairs, we find
on the roof the following weather