The Indianapolis times. [volume] (Indianapolis [Ind.]) 1922-1965, 1933-06-12
-Dietz on Science
MANY WEATHER
RIDDLES SOLVED
BY U. S. BUREAU
Research on Large Scale
Needed for Measuring
Rainfall.
BY DAVID DIETZ
Soripps- Howard Science Editor

III IN IL I'M ~
Sorinps-Howard Science Editor
Scientific research must be car
ried on continuously by the United
States weather bureau. For, while
weather is as old as the world, scien-
tific meteorology still is very young
and many important factors in the
weather still are understood imper-
fectly.
The excellence Of the present fore
casting service is due to the large
amount of scientific research which
has been carried on in the past.
BY act Of congress, it is the duty
OF the United States weather bureau
to keep continuous records of the
state and condition of the sky and
the air at many places, to issue fore
casts, based thereon, of the tempera-
ture, wind rain, and other weather
elements of the morrow and the day
after, and also from these records
to discover the climatology of each
and every portion of the country"
DR.. W. J. Humphreys, physicist Of
the bureau, tells us.
Reliable Records Needed
ITO perform this public service
at all satisfactorily, it was neces-
sary first to provide for obtaining
reliable records of the temperature
of the air, degree of humidity,
amount and kind of precipitation,
wind direction and velocity, cloudi-
ness and sunshine, and also very
accurate measurements Of that
special condition of the atmosphere,
namely, its pressure, which though
inconspicuous to our senses never
theless is so related to weather
changes as to be exceedingly val
liable to any one who, from today's
weather, forecasts that of tomor-
row"
Because of it's duties, scientific
research became necessary at the
very start. The bureau needed,
from the beginning, methods for
making observations and instru-
ments with which to make those
observations.
Problem Is Difficult
Those without experience in such
matters might think that this would
be the easiest sort of thing to do"
DR.. Humphreys says. For instance,
one who has not tried it naturally
is cockSure that an accurate meas
urement of precipitation is the
simplest thing in the world to eff
feet, and indeed rough measure
mentS of it are easy to make and
have been made for many centuries.
Clearly, too, the measurement of
the water caught for that purpose
offers no difficulty, but investigation
soon revealed the disturbing fact
that the amount of water captured
by any and every rain gauge varied
with the nature and proximity of
neighboring objects, height of the
catching vessel above ground,
strength of the wind, and other
factors.
Much Investigation Needed
Hence a number of lnvestiga-
lions were required to determine the
kind of apparatus to use to catch
the rain, where to expose it, and
how to construct it, that it auto
matically would make a reliable and
convenient record of the time of oc-
currence, rate of fall, and total
amount of each and every rain that
came"
Difficulties, however, did not stop
at that point.
"A device that IS satisfactory for
catching rain may be, and generally
is, poorly adapted to the catch and
measurement of snowfall" he con-
tinueS.
Importance of Snow
The problem of making measure
ment of snow practicable and
accurate entailed another series of
Investigations.
DR.. Humphreys points out that the
amount of snow accumulation must
be known with accuracy, particu-
larly in mountainous regions.
In many cases it determines the
volume of stream flow and the
quantity of water available for irri-
cation and other uses in the valleys
and plains below during the coming
summer and fall he says.