Year: 1878


of few lines telling the probabilities"
Perhaps you think that some mysterious per-
son climbs up on top of his house, looks
around little at the clouds and the weather
cock on the barn, and then goes down aud
says that he's sure there's going to be'a spell
of weather Of some kind. What do you say
to finding out all about i'll


There are connected with this service about
two hundred stations, scattered all over the
country


These stations are established and equipped
on purpose for observations and are not con-
nected with any other branch of the govern
ment service-such as naval stations and the
like.


The central Office is at Washington. At all
stations there are three observations taken:
viz. 7:36 A. NJ, 4:35 p. NJ. and IL o'clock
P NJ washington time) the results of which
are telegraphed to Washington. There are
also three or four observations taken daily
! G. 4. NJ. , pm. and p NJ and sent by mail
| to headquarters once a week. But the tele-
! graphic reports are the ones in which we are
most interested for upon their arrival at
! Washington chart is Immediately made ont
and sent all over the country. So you see
| that there must be three of these charts made
and sent out every day. The reports tele-
| graphed include the state of the barometer,
Thermometer, hygrometer Showing the mois-
turc Of the atmosphere), direction of the
| wind, velocity in miles, and pounds of pres
! sure, kind and amount of upper and lower
] clouds. with the direction and velocity of
each stratum, rain, hail, snow or sleet as the
case may be the report closing with a state
ment of the general character Of the weather.
| These reports are sent in cypher, not on ac-
count of secrecy, but that they may be more
accurate, especially where figures are neces-
/ sary.


II the wind is from the southwest and the
weather foggy they the word Hermit"
! Should the temperature stand at fifty degrees
the word Fight is the one sent. You can
readily see that this system saves much time
as well.


On an elevated place, where the wind is un-
obstructed. are four hollow hemispherical
cups placed in a horizontal position so as to
catch the wind. These are at the top of a
registering rod. This rod is in connection
with n disc that is in its turn connected by
| electricity with registering drum in the Of
| fee of the station. This little machine is
| called an dneniOmeter. The disc on the rod
with the cups is so arranged that it makes
one revolution as each mile of wind passes
and little wire point on the disc comes in
| contact with another point upon a stationary
| edge at each revolution. As these points
come together the electric circuit leading to
the registering machine in the Office is com
| plete, and so for a second a small magnet in
! the machine is released, giving a little jerky
| motion to a pencil point that is resting on a
| drum covered with paper and kept revolving
| by means of clock work The paper over
this drum is divided by lines into spaces rep
resenting hours and fractions thereof The
pencil follows a straight line until the mag
net is released. when the lead makes a little
mark to the left and then flies back again.


Now as you know that the pencil moves
af
you can see that the spaces between those lit
tie marks on the drum of the dHtR,0meter rep
resent miles. and by seeing how many time
| spaces Gas lined on the paper have been pass
| ed by these marks since the hour began. you
can tell how many miles per hour the wind is
blowing.


You who live in seaport towns have often
! noticed the harbor full of vessels at anchor
late in the afternoon. You wonder perhaps
why they don't sail away, for the sky is clear
and the wind moderate. But if you knew as
much as do the captains of these vessels you
would look up at that high building yoDder,
| where a red flag with black centre is flying
That is the cautiouary signal. for Washington
| has telegraphed that storm and wind are com
ing. At night this signal takes the shape of
red light from lantern on flag staff.


In New York city the signal service Office
is situated on the top Of the Equitable Insur-
ance building, which is in the lower part of
the city and near the bay The principal tel
| egraphic signal stations send to the New
York Office three times daily. The clerk here
furnishes all the different exchanges and mar
itime offices with translations of the cypher.
There is also Farmers Bulletin" made out
at all the principal signal stations. Most of
the stations throughout the country have the
necessary type and presses, and the probabil-
ities are printed carly in the morning (three
or four o'clock and mailed to postmasters in
the vicinity. These bulletins are hung up in
the post offices and the farmers can examine
them when they come for their letters. 1t is
often of great Importance for the farmers to
know when it is going to rain. The New
York station sends out 1Oi of these bulletins
every morning.


As reports are received at the Washington
Office the clerk takes a chart and draws red
lines upon 1t, connecting places having the
same atmospheric depression. Thus the map
shows in curying red lines the locality where
in the pressure is at its highest and lowest
points. High pressure always moves towards
low pressure. BY low pressure the Professor
simply means less air. as shown by the bar
ometer You've often heard Of storm centres.
A storm centre is at the locality where the
pressure is at the lowest point, and you know
that as mature abhors a vacuum" the denser
air surrounding this storm centre must rush
in to fill the space. The greater the differ
ence between the atmospheric pressure at the
storm centre and that in its vicinity, the
greater the force and speed of the wind, of
course; and as air has been taken from the
neighborhOOd to make up the deficiency, so
that in turu has to be supplied from its vicin-
ity, and so ON back over the country, the
wind getting weaker and weaker as it leaves
the storm centre


Now, as all the signal stations have been
informed by telegraph of this storm centre,
the officers can foretell the approach of the
wind very readily, and by knowing the
amount of moisture, the temperature and the
amount of cloudiness at the different locali-
ties, the state of the weather accompanying
this wind can easily be determined.


There are quite often several storm centers
at the same time in different parts of the cOun-
try, which lead the winds lively race, as
each storm center causes the wind to blow in
two different directions For instance Let
us suppose there is storm center in Tennes-
see, and that the highest atmospheric pres
sure is in Eastern Canada, most of the coun-
try east of Tennessee would have northeast
wind, but west of the storm center the air
would rush in from the opposite side, and the
direction Of the wind would be reversed.


The station officers call high wind a
storm, whether accompanied by rain or not
Sea captains seldom venture out of harbor
when the wind is blowing at the rate Of twen-
ty-fve miles an hour. When the wind is
blowing from forty to sixty an hour it is called
a gale. From eighty TO one hundred and fif-
ty miles, hurricane. You have seldom felt
the wind at greater speed than sixty miles
an hour.


The weak point in the signal service is
something the service cannot help at present.
They have no means of recording the state of
the weather on the Atlantic and so when
the wind is from the east it is pretty hard tel
ling what is going to happen. The Professor
thinks that one of these days even this diff
Guilty will be removed for perhaps they may
put vessel in mid ocean and send ON des-
patches by means of the Atlantic Gable. A
storm would have to work pretty hard to get
| l.,f,,