The Monitor. [volume] (Woodstown, N.J.) 1884-1892, 1889-10-11
PREPARING WEATHER REPORTS.
low sold Prob Make His Forecasts of
Atmospheric Changes.

L ia Up ~
dav to ask Gen. A. ". Greedy how he
and his fellow conspirators regulated the
weather of which this season has been
so prolifc. | found the lucky and
plucky Artic explorer at his desk, robed
in a full suit of white flannel over a
checked flannel shirts dream Of COM
fort and a very delightful antithesis to
the Young lieutenant who, six years ago,
was waiting for death at Camp Sabine.
"What is the percentage of right esti-
| mates Of this bureau:
at averages something over so per
| cent. You would not think 5 to read
the papers. But the fact IS. when prob
abilities prove to be correct newspapers
do not notice it; they only have some
thing to a when we miss fire. y New
England daily paper said last Wednes-
dav that our estimates for that section
hadn't been right in a week sent
the statement to my expert, whose busi-
ness IS verifcation. and he went over the
facts and figures, and found that 81 per
cent. of the predictions of the bureau
for the period and ssction had been cor
rect"
"How do You make your estimate for
| tomorrow 5 weather, general:
Il could give you a statement OF 1t,
but | had better refer you to Capt. Dun
woody. the officer who has had predic-
tons in charge for many years. He is
at this moment making up his weather
sheet for tomorrow.
Gen. Greedy kindly walked with me
out of his handsome room into the low
annex adjoining, where Capt. II. II. G.
Dunwoodv, of the Fourth artillery,
makes his working headquarters. and
there l was presented to nina soldier
" built officer, with a military bearing
and alert face, his short hair turning
gray as he talks about the weather.
Here they are" he said, touching
with his hand d bushel of mussed up
telegraph dispatches, "thc data ON which
we make computations. These Were re-
ceived at s o'clock this morning, Wash
ington time. from our $50 stations in al.
pats of the country. These all reached
us within thirty minutes this morning.
Similar dispatches come three times a
day"
They tell YOU" I .ventured. what
the weather has been and is. What the
people want TO know is how you guess
what the weather is going to be. Or
perhaps | should not use the word
guess:
Certainly you should" answered
Capt. Dunwoody. "sGuess' is a good
word. Much of our prediction is ece
sarily sonjecture-that is. it is an at
tempt to solve q problem when some OF
the important elements are missing.
These dispatches tell us five important
things about the prevailing atmospheric
conditions in $50 places: /, the measure
of the barometer: ., the thermometer;
3. the force and direction of the wind:
/. the character of the clouds; 5, mois-
ture. or hydrometic conditions. Here
we have the weight Of the atmosphere,
the heat, the wind. the clouds, the rain
in $50 places-an important basis for
4 judgment. When we get these dis
patches we take five blank maps of the
United States and Canada and outline
the five conditions-heat, rainfall, ETC.,
so that the state of the Union, 50 to
speak. becomes pictorial. Now we have
something for any analytical mind to
work on-the weather in every terri
tory. Here are the maps for today.
Isotherms are drawn through all the
places of equal temperature; isobars over
all points of like barometric pressure,
and so on.
"You see there is a circle marked
frost in the cranberry region of upper
Wisconsin. The fact that frost is there
today comes to US by telegraph. But ]
predicted it Yesterday morning and sent
warning to the cranberry region tC
look out suppose some of them did.
The day before yesterday frost was re
ported in Pembina, northern Minnesota
High areas generally move east TO south,
east; and thought it safcto predict that
this cold wave would go to the Gran
berry region. 1t did and it reached
there in just twenty-four hours, a | an
ticipated. The trouble is that not one
half of the farmers got the warning il
time. Some years since l sent a dispatcl
to Madison. Wis, warning them tina
there would be frost the second day af
ter. The editor who handled it stuck il
in Il drawer and there it slept. / after
ward heard Gen. Rusk, now commission
er of agriculture. say 10 the Wisconsin
state grange that if all organization ha(
existed to distribute that prediction i
would have saved 800, coo to the farm
ers Of the state. The great need Oh thu
service today is distribution. Emphasize
that. please. Some provision should be
made by which the important ~probabili
ties can speedily get TO the farmers fol
whose protection they are chiefly use
full"
How long are your predictions:
"Twenty-four hout5; sometimes thirty
six. Occasionally, when indications are
very clear, forty-eight. We shall extend
the time & little next year. Weather
remains more settled in winter and fore
casts are easier"
From what does your 90 per cent. Of
failures result:
From a lack of knowledge on oul
part: from our ignorance of prevailing
conditions. If we knew more we coull
guess better. Washington Cor. Phila
delphia Times.
Unlimited Credit.
a country schoolmistress had mucl
trouble with her pupils, and to avoid i
made her examples placed before then
of an explanatory character or illustra
" ri