Year: 1871




7O2 :


> 1 8


5 1O2


The first three figures in the first line show the reading
of the barometer in thOusandths Of inches and written
full would be, Barometer 2944 inches" The last two
figures in the line show the number OF the station,
No. 26 being at Montgomery Ala. In the second ne the
first two figures show the hight of the exposed Their
mometer and written in full would read, Thermometer
7Oo !" the next two show the relative humidity of the
atmosphere it being in this 28 per cent OF satura-
ton. The last figure shows the direction of the wl
north being represented by one northeast by two east
by three, 90 In the third line the first two figures
show the velocity of wind, the next two the day Of
the month which the report made and tho last
the of the weatheTzero indicating clear weather.
one, fair; two. cloudy three clearing up
after storm, &c. The. first figure In
the last line shows the amount and kind
of apper Clouds zero indicating clear sky hazy
atmosphere two sky itos and three 'toi4covered with
cirrus Clouds four sky to and fve,3 to - covered
with cumulus clouds. The word "bank" denotes that
the upper clouds hidden. The second space In the
last line shows, by similar arrangement, the amount
and kind of oioer clouds and, in the example taken
means that the sky from to entirely covered with
stratus clouds The last three figures show the amount
Of rainfall during the past "a hours in inches and
hundredths of inch The afternoon and night re-
ports are made by the Of 10 words represented by
figures as in the morning report The Government pays
to the Western Union Telegraph Company two cents
word for each circuit which the message passes
and the yearly expense is about $4,000 The weather
reports precedence of all other until they
are complete The operator in Gen. Myers Office here
is on three circuits one to NewYork one to Chicago
and one to New Orleans


SOWING THE INFORMATION DRoADcAsT-sToRMs.


As as the reports received they are translated
into ordinary language and manfOded for the press
The familiar buetin-sheet is then filed out and posted
of OF Tra1P
merce and other conspicuous places The manifold maps
are then printed and distributed and lastly the War
Department Weather Map" is changed As these each
contain explanation il is not necessary to repeat 1t
here.


Having received the reports they are given to Prof
Able the meteOroogt OF the Signal Corps who at once
transfers them to map, in order to at glance the
exact condition Of the atmosphere in every part OF the
country and what changes have taken place since the
report He then makes out synopsis OF the weather
during the last hours and prepares his predictions In
order to understand how these predictions are made 1t
is necessary to refer briefly to the generally received
theory OF storms 1t is well known that there are in the
tropcs constant winds that, with little variation blow
in the same direction during the whole year. Those
south of the equator the powerful blow toward
the northwest and known the "sOutheast trade
winds - and those north Of the equator blow toward the
southwest, and called the northeast trade
winds" Between the two there is a narrow belt Of





if the southeast trade-winds should at any
time reach north of the equator, and
there come in contact with the northeast wind the
most natural result iwould be a rotary motion Of the
wind, turning jim the direction opposite Of the
hands of clock, and moving in a northwest direction.
In this way ii supposed the cyclones the West In
dies formed On reaching the Gulf Stream they take
the course Of that great ocean current and finally
lost in the ocean. But, sometimes ii is supposed
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 the southeastern coast OF the United
States 1t has also been proved that the air which
tradewnds bring to the equator rises there TO great
attitudes and flows back to the poles. Now il these
winds in the northern hemisphere meet the colder cur
rents from the pole, the result would naturally be
storm, which would first itself in the north
part Of the continent and having crossed the Rocky
Mountains would the United States in an
eastery south-easterly direction The observations
of the Signal Corps thus far, to confirm these theo
res the storms that have occurred during the
past Winter and Spring having been first observed in
the southwest, northwest the eastern coast
the Southern States and the wind at various stations
on the outskirts OF the storm blowing in circle, the
centre Of which the point Of lowest barometrca
pressure.


| TRACKING A sToRM-wARNISGs OF ITS APPROACH.


Prof. Able having, therefore marked his map accord
ing the report by lines those places at which
barometer stands at the hight These isObarO
metric lines generally found to form circles ovas
Of these figures and In the region Of lowest pres
sure Q the barometer stands very low there storm
generally reported The next report Is likely to show
that the region OF lowest has moved toward Tho
east, northeast, southeast it's direction being IL
great determined by the mountain ranges riv
e1s the temperature Of different parts OF the country
and various local causes. The direction and rate al
which the storm has moved since the last report with
I thu Of lOcal
| TO affect IT, form, then, the basis for prediction
! IT, for instance, storm which has moved II
norheastery direction 800 miles during the last eight
hours is in Indiana and inois, within 800 miles
the lakes II is safe TO predict that 1t will reach the
shores within the next eight hours, and to ship
masters and others to prepare for it, II will thus be
that the probabilities published every day are nc
wild guesses but are founded the best Of data and
may, therefore be read with great degree OF conf
denee The United States far avorably situated
for the observation of coming storms than any Euro
pean country yet the records show that in England
Is per cent of the storm warnings have proved correct
while France the percentage has been as high as H.
| TO- 50 aDd a. No system Of warning signals for ship