The Charleston daily news. [volume] (Charleston, S.C.) 1865-1873, 1871-07-29
instrument is 80 delicate that it registers the
thousandth of an inch Of rain.

ments the observer sergeant is ordered to his
station. He Immediately procures room in
the upper story of building, with windows
facing north, and near the telegraph office
which is to receive and transmit his reports:
He Immediately sets up his in'truments and
furnishes his office, and then reports to the Of
fee at Washington that he is ready to begin
observations. Six observations are made each
day at each station, three to be telegraphed
and three to be sent to the Washington office
BY mail Those to be telegraphed are taken
simultaneously by all of the observers at 8
o'clock A. NJ, 4.30 P. N. and midnight,
Washington time; Those to be transmitted
by mail are made at O'Clock A. NJ, and 2.
and P. NJ. local time. The morning re-
port, which Is the most complete, is taken
in the following manner: First, the height
OF the barometer is taken, and, after correc'
ton for elevation and temperature, notea Ia Ia
hundredths Of inches; then the reading OF the
exposed thermometer, the relative humidity
and the direction of the wind; after this. the
velocity of the wind Is recorded, and then the
state OF the weather, ssclear,r 'sfair," slight
rain,'' heavy rain, J" '.snow' or "hai," !"
&c. In this report the amount and KIND
of upper and lo,oer clouds are also given,
past "a hours. This entire report, BY
the use of figures, is transmitted with only
20 words of telegraphing, and from It the
elaborate reports furnished to the press are
made out. The afternoon and night reports
are made by the use OF 10 words Represented
by figures as in the morning report. me
Government pays to the Western Union Teie-
graph Company two cents word for eacn
circuit over which the message passes, and
the yearly expense Is about S6o,0O0. The
weather reports have precedence Of all other
messages until they are complete.
SOWING THE INFORMATION BRoADCAsr-sToRMs.
Having received the reports, Professor Able,
the meteorologist OF the Signal Corps, at once
transfers them to map, In order TO see OF
In every part ofthe country, and what changes
have taken place since the last report he then
makes out synopsis of the weather during
the last "a hours, aud prepares his predictions.
In order to understand how these predictions
are made, it Is necessary to refer briefly to the
generally received theory OF storms. @ IL Is wen
known that there are, In the tropics, constant
winds that, with little variation, blow IN the
same direction during the whole year. Those
south of the equator are the more powerful,
blow toward the northwest, and are known
as the s'southeast trade-winds;" and those
north of the equator blow toward the south
west, and are called the northeast trade
belt of equatorial calms and rains. Now It lS
evident that If the southeast trade-winds
should at any time reach north OF the equator,
and there come in contact with the north
east wind the most natural result would be
rotary motion of the wind, turning ID
the direction opposite to that OF Tue
hands of clock, and moving IN northwest
direction. In this way, it Is supposed, the cy-
clones of the West Indies are formed. On
reaching the Gulf Stream they take the course
of that great ocean current and are finally lost
in the ocean. But, sometimes, 1t Is supposed,
a smaller storm Is thrown of from the large
cyclone, which, taking westerly direction,
passes through the Gulf of Mexico and strikes
the coast of Texas, or first reaches land on l1e
southeastern coast of the United states. II
has also been proved that the air which the
trade-Winds bring TO the equator rises there 10
great attitudes and flows back to the poles
Now If these winds in the northern hemls-
phere meet the other colder currents from fhe
pole, the result would naturally be storm,
which wouldAfrst show itself In the north
western part of the continent, and having
crossed the Rocky Mountains would move
across the United States in an easterly or
southeasterly direction. The observations of
the Signal Corps, thus for, seem to confirm
these theories, the severe storms that have
occurred during the past winter and spring
having been first observed In the southwest,
northwest, or. on the eastern coast of the
Southern States. and the wind at various sta
stions on the outskirts of the storm blowing In
q circle, the centre of which was the point Oh
lowest barometrical pressure.
TRACKING AsToRM-wARNrNG OF IT'S APPROACH:
Professor Abbe, having therefore marked
his map according to the report. connects oy
lines those places at which the barometer
stands at the same height. These isoDarometric
lines are generally found to form circles,
oyals, or arcs Of these figures and In the re-
gion OF lowest pressure (lt the barometer
stands very low there) storm is generally re-
ported, The next report Is likely to show
that the region OF lowest pressure mas moved
toward the east, northeast or southeast, us o.
rectlon being In great measure determined oy
the mountaln ranges, rivers, the temperature
of different parts OF the country, and various
local causes. The direction aud rate at which
the storm hiss moved since the last report,
with the consideration Of local influences
which are likely to affect it. form then the
basis for prediction. If, for Instance,
storm which has moved In q northeasterly d.
rection 800 miles during the last eight hours
Is now In Indiana and Illinois, within 800 miles
of the lakes, it is safe to predict that 1t Will
reach their shores within the next eight hours,
and to warn shipmasters and others to prepare
for it. It will thus be seen that the "probabili-
ties" "as published every day, are no wild CUES.
ses, but are founded on the best of data, and
may, therefore, be read with great degree OF
confidence. The United States are far more
favorably situated for the observation of COM
Ing storms than any European country, and ].
yet the records show that in England 73 per
cent. OF the storm warnings have proved cor
rect, while in France the percentage has been
as high as II, rs, 80 and 81. No system OF
warning signals ior shipmasters and farmers
has yet been adopted in this country, though
the subject Is now under consideration. Tue
predictions made all relate to storms OF gen.
eral nature; and net TO local disturbances,
such as thunder-showers, &C., which, though
they may affect the course OF q storm, gene.
rally extend over small areas. Warnings of
these might be given from one station to an
other, though as yet no arrangements for such
warnings have been made. General Myer has
only just begun his work, the reporting of the
weather having been assigned to the signal
corps only last November, but not only the
possibility, but the great advantages Of re-
porting the approach of storms have already
been demonstrated, and there can be no doubt
that this division Of the War Department will
rapidly develop, until, in time of peace, it will
be the most important in its practical results
of all the bureaus in that department.
THEIR DOINGS IN JYASHINGT0N.
WASHINGTON, July %.
The Ku-Klux committee examined 81. W.
r,,;on of North H,rolipo today Hp eafd thSt