The Democratic advocate. [volume] (Westminster, Md.) 1865-1972, 1875-08-21

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one IN use at the signal station turns hand
upon dial having the points Of the compass
marked upon it, placed in the instrument
shelter, and which shows the direction OF the
wind exactly.
The rain gauge consists Of straight cop
per tube, circular in form, having at the top
a funnel with an area ten times the area Of
the bottom Of the tube. This is exposed in
the middle Of the roof of the Chamber of
Commerce. When the rain falls it is caught
in the funnel and falls TO the bottom Of the
tube. 1t Is measured at the end Of each "a
hours, and il an inch Of water is found in the
tube il indicates that there has been a rainfall
equal to one-tenth of an inch.
The maximum thermometer is used to mark
the maximum temperature 10 "A hours. II is
common mercurial Thermometer, the bore
Of the tube Of which is contracted for n vesy
short space near the bulb to an extremely
minute diameter, the tube being larger on
each side Of this contraction. The thermome-
ter lies horizontally, and as the temperature
rises and the mercury expands it is forced
through the minute opening and passes along
the tube until it marks the highest tempera.
ture reached during the day. When the tenn
perature falls the mercury in the bulb con-
tracts, and the column Of mercury lying in the
horizontal tube breaks of at the point of
contraction, and that portion below it sinks
toward the bulb, while the column above the
contraction lies in the position to which it has
been forced by the high temperature and re-
mains there until the instrument is read by
the observer when the mercury is forced back
past the contracted point in the tube by
whlrling the instrument around, the centri-
fugal force thus exerted accomplishing that
end.
The minimum thermometer is spirit
thermometer, which lies horizontally, into
the bore of the tube of which is inserted
delicate index of enamel, which does not
quite fill the bore. As the temperature rises
the spirit passes around the index without
moving it, but as the temperature falls when
the head Of the column Of spirit reaches the
index, the attraction Of cohesion causes the
index TO move back with the spirit and to stop
at the lowest point reached by the thermome.
ter. The maximum and minimum thermome.
ters are read once in "a hours.
THE DAILY OBSERVATIONS.
There are seven observations taken daily,
viz Local observations, which are not tele-
graphed to Washington, at 7 a. m, Up. IN.
and p. M, local time; Telegraphc observa-
tions al 1876 a. m, 4.35 p. m. and IL p. m.
Washington time, and an observation at noon,
Washington time, which is teegraphed 10
Washington whenever the barometer falls
l5-l00 of an inch or more. The telegraphic
observations are taken at the same absolute
moment of time, the observers at all the sta
tions receiving the Washington time daily by
telegraph, from the central Office The re-
suits OF the observations are at once tele-
graphed to Washington, where the probabil,
ties are calculated, and Immediately telegraph.
ed to the various stations. Experience has
shown that of these probabilities as issued,
10 TO 80 per cent. are verified. In December
last "a per cent. of the predictions of the
service proved true, and in June last s7l per
cent.
CAUTioSARY SIGNALS.
The cautionary signal is red flag with
black centre by day, and a red light by night,
and is displayed when the information in the
possession Of the officer leads to the belief
that dangerous winds are approaching. 1t is
shown from the tops Of high buildings, flag
poles, lighthouses, lifesaying stations and
other points where it is most apt to be seen by
those most interested.
Weather maps and "iarmers' bulletins
containing synopsis Of the observations for
the past ~ hours and the probabilities for the
coming "a hours, are printed and issued in
Washington, New York, Philadelphia, Gin
cinnati, Chicago and st. Louis. The Farm
ers' bulletin" is printed and issued in several
other places.
The weather maps are distributed and post.
ed throughout the cities in places where il is
supposed they will do the most good, and the
farmers bulletins are sent by mail to the post
offices throughout the country. The weather
map shows the direction Of the wind, state Of
the weather, thermometer, barometer and
velocity of the wind at every station in the
United States at the II o'clock p. m. observa.
ton. They are issued daily at | o'clock in
the morning from the various printing sta
tons. In Philadelphia 210 maps and 72l
farmers bulletins are issued daily. The maps
are distributed in the city by the Board of
Marine Underwriters. The bulletins are
mailed to the various postotices in this dis.
trict Of country. 10 this city maps are
printed from the observations made at 1885
a. m, and by 1l.S0, a. m, are posted in pub
lie at the Commercial Exchange, the Mer-
chants Exchange, the Maritime Exchange,
the Charter Oak Life Insurance Company's
Mercantile Library and Post-office.
During the ak months ending June 81 last,
there were issued from the Philadelphia of
flee 30,665 weather maps, 1854 farmers
bulletins, 4,2S3 copies of the synopsis of the
4.35 p. m. and 1886 p m. observations, and
2,434 copies Of the 1890 q. m. and 1880 p. m.
probabilities, besides sl5 reports to the press.
The Office is in charge Of Sergeant Charles NJ.
Hobbs as observer, and six assistants, two Of
whom are printers, and print the weather
maps and bulletins.
Philadelphia is one Of the most important
of the Offices Of the service, being situated
directly on the line Of the Government tele-
graph communicating with the most danger
Gus portions Of the Atlantic coast.
The service has already accomplished won.
ders, but its value will, no doubt, constantly
improve as the observers and officers gain
experience. The principal difficulty il has to
contend with is the want of money. The ap.
for this year is only $3.50, 900 for
all the expenses of the department, and if the
system Of cautionary signals was to be the
means of saving but one ship in year, or if
at each Of the postofiiees to which the proba.
bilities are mailed one ton Of hay is saved
from approaching rain and consequent ruin,
the entire expenses would be saved to the ma
ton. The observers, who hold the rank Of
sergeants, are paid but small salary, and
the assistants still less. The observer must
be a man Of superior intelligence and educa-
uoti; VI gentleinaniy hnu httfacuVe address,
and able, in order TO make the service useful,
to place himself in constant contact with bus.
iness men and associations. He must under
stand the Morse system of telegraphy, and be
able to send and receive his own dispatches,
and he has no hope of promotion. The con.
sequence is that generally the observer only
remains in the service until he can obtain
employment which will pay him better in pro-
portion to his abilities, and just as he obtains
enough experience in the service to be valua.
BILE as a skilled meteorologist he leaves to
take place that will pay him better. If the
pay were high enough to induce these gentle
men to consider their positions permanent, Of
course they would be more diligent and earn
est in the work, and the service would be cor
improved.
Mr.. Hobbs, the observer at this station,
states that as his Office is public institution,
he will be glad to see any person who may be
curious about the service and desires to know
how il is conducted, and to explain to any
one the manner of making observations or
dedueing the probabilities from them.
How "Ir RAIxs.n
As great many broad districts of the hab.
table globe, including an extensive area Of
our own country. are in trouhla nj thie fis.,o |