The morning times., 1896-04-28
Weather Bureau to Undertake a
Unique Task.
WHAT IT Is DONE FOB
Scientific Observati lions to Be Syste-
maticaily Conducted, Heights, Dt-
mensions and velOcities of Clouds
to Be Ascert aimed to AID in Predict
ing the Weather More Accurately.


Bureau for this novel line OF special study,
purposed TO greatly increase the weather
wisdom OF its forecasters and observers.
Very little is now known by even the most
learned weather students concerning the
actual measurements, motions and positions
OF clouds, although the latter are the most
conspicuous factors of daily weather pre-
diction.
The new cloud surveying will begin on
the first of the month, to continue exactly
one year, in conjunction with all the other
weather SERVICES of the world. The Drin-
cipal observations in this country will be
made in this city, but other selected sta
tions IN various states will cooperate.
The United States, having the greatest
continuous extent of territory and the
most efficient weather service OF all coun
tries interested, will establish the most
stations. The principal cloud Observable
ries are being now arranged at New York,
Blue Hill Observatory, Boston, Buffalo and
Detroit, Tie two latter cities will study
the cloud formations over the lake regions.
representatives OF the different national
weather services have been arranging Tor
this extensive work for several years.
uniform system OF observation was lately
agreed upon by the International meteoro-
logical congress held at Munich, and accord
ing TO this all studies in the various coun-
tries will be made simultaneously.
CHIEF BIGELOW IN CHARGE.
Chief Moore has appointed Prof. Frank
81. Bigelow, one OF the Weather Bureaus
chief metereolOgists, to direct the work on
behalf OF the United States. Prof Bigelow
described his plans in an interview with q
Boston Transcript corresondeut, when Wis
tied shortly afterward.
The result of the cloud survey will be the
beginning OF great map OF the atmosphere
above the earth. When geologists plot a
chart of the earth's crust they show each
layer OF mineral strata. These meteorol-
ogists will show in their new map the lay
ers of gaseous strata above the earth. We
have charts or our solid and liquid pos
sessions.
What is now wanted is a chart OF our
gaseous possessions. Such "a chart if made
in model form would fit over a globe like
the thin hull OF a walnut. Look at the
clouds. Unless seen in contrast the un-
skilled eye can appreciate little If any diff
ference in their heights. Yet some are
almost ten miles away, while others are
do wn upon us. The skilled eye of the
mctcorologist, however, has learned to
appreciate which clouds are higher than
others. But what arc their exact heights?
HOW THEY ANSWER.
Bymeasuring he precise distance between
a cloud and the earth, and by learning its
exact direction, you will know that there
is a current of air at the same height,
moving in the same direction. Next learn
the velocity OF the cloud, and you viii
know how fast The air current is moving
Take twenty clouds OF various heights.
Some move in some directions, others in
Others. By observing these particulars
every day for year. you will be able 10
make averages upon which 10 base the
lines of your chart of the atmosphere. An
estimate ofa cloud dimensions will further
foreieil its capacity for rain, snow. wind.
etc. Learn its direction and velocity and
YOU will know which way il is going and
how long il will take to get there.
But how will these measurements be
made? The surveyor may measure the
height of mountain by using the the odolite.
He first establishes a base line on the
| rth and measures from each end the
| angles to be used in his computation. By
| applying certain formulae he estimates
| the dimensions of the mountain by triangu-
| lation. A cloud might be called great
| mountain or mountain chain of vapor. Prof.
| Bigelow has established his base line be-
| tween the top of the Weather Bureau and
| the west pavilion of the State, War, and
| Navy Department.
] Both stations are to be in direct tele-
/ phonic connection. On each observatory
will be placed theodolitc. especially fitted
for cloud surveying. These will not be
| fitted with telescopes as used for land sur
| veying. Clouds W hen brought close TO the
eye present an ever changing appearance.
| A particular point cannot be viewed in this
| way since the telescope shows the gradual
| blending OF clouds edges into transparent
| atmosphere. Instead of the telescope.
| long cone-shaped frame, with cross-hairs
| arranged over the far end will be used.
| Suppose that conspicuous cloud appears
| in the n ortb.
OBSERVATIONS TAKEN.
The observer at the Weather Bureau tower
calls the observer at the other end OF the line
by telephone, and they agree upon a certain
pointa at the top of the cloud. They compare
watches and agree to ia ke measurements at
the same minute precisely. The angles are
jotted down in their note books. similar
measurements made estraightway at point
| at the bottom of the cloud and at either end
SiInilarme asurements may be peatedevery
minute or two, as long as the cloud remains
in sight. By comparing notes and applying
formulate they afterward learn how high the
cloud was above the earth, how high it was
from bottom to top, how long from end
toend, how IA r it Travelled in giventime and
whatwas its direction. Such announcements
willcontinue during ca ch working hour every
day, during the year specified. AS soon as
| one cloud is finished another will be taken
up From May 1, 1896, 10 May 1, 1897,
Ill sorts of clouds will be seen representing
every phase of usual weather.
| In New York, Boston, Buffalo, Detroit,
and such other stations as may later fall in
line, more simple system will be en-
| ployed. Instead of establishing base lines
and using the complicated equipment de
| scribed, each cloud observer will be fur
| niShed an interesting instrument called tn G
nepboscope. When we see cloud moving
in the sky, apparently from north to south,
| we do not know whether in addition to tina {
direction 1t may be coming toward us or
going from US. The nephoscope will dis
cover this. 1t has been used for a similar
l purpose at sea, but has been improved es-
pccially for the cloud survey. The nepho-
scope is simply round, black mirror, re-
volving in a circular. sta tionary frame the
inner edge of the latter being graduated to
the compass scale.
MEASURED BY SHADOWS.
Attached to the frame is long, jointe d
arm, with a knob at the end. The center
Of the mirror is marked with an indente d
dot. From this is dra wn q straight groove
to the outer edge. When placed undnr the
| sky the black mirror sho " S the refle c;ion OF
passing clouds. A particular point ON a
cloud is selected, and by moving The eye
tlilS iild DC W dpPNdi diiCttlS OhtA
the dot in the center of the mirror.
The arm is next moved until the shadow
of its knob appears to cover the same dot
As the cloud moves, the point upon It leave
| the dot, IL the eye be held still. IL the ey'
be moved so that the shadow of the kno
continues TO cover the cloud-point, these TIVE
| will appear 10 travel over the mirror 10
5 | ward the edge. IL the mirror be turned o.
it's pivot until the grooved line marked frOu
) Its cerster 70 edge appears to be the path O