The National tribune. [volume] (Washington, D.C.) 1877-1917, 1890-08-07
THE WEATHER.
Rainfall and lis Measurement.
BY LIEUT. J. p. FINLEY, U.s.. SIGNAL SERVICE.

! anu btb ReAsHEemeHtp
BY LIEUT.. J. p. FINLEY, Us. SIGNAL SERVICE
tCorrespondence. invited. suggestions desired
| and information oheerfully furnished. Every of
fort employed to make this Bureau OF practical
| TO the readers of THE NATIONAL tribune. All
| communications should be addressed Weather
| THE NATIONAL TRIBUNE Office Washington, ID. q.
There is hardly subject in the whole range
OF physical science that is attracting more Mt
tentton In this country to-day than that prod
uct of the atmosphere technically called
precipitation, but ordinarily known by the
| common names of rain and snow. It's excess
| or deficiency seriously affects the commercial
and agricultural interests of this country, as
well rs the health and happiness of the people
The reclamation of the arid lands of the great
| West must depend upon n thorough study and
knowledge of the distribution of precipitation
over that extensive region. IL is not work
| which can be taken up to-day and finished to-
| morrow, but on the contrary requires tho pa
tent and exacting toll of years in order to
obtain results upon which reliable estimates for
! future work can be based.
Tho railroad engineer must know from the
| meteorological records of the country where
and with what strength TO build his bridges to
| withstand tho force of n swollen, rushing tor
| rent 1t Is not tho average rainfall Mt that
| place which will give him the important infor-
nation, but rather tho rate of fall per hour and
the maximum amount that has fallen in any
% hours. We must know exactly what kind of
data Is wanted, and then know how and where
to obtain it,
In tho construction OF railroads through
mountainous countries il IS extremely impOr-
tant to protect the tracks from drifting snow
Just whore to build the snow-sheds and with
what strength they should BIO erected, depend
upon an accurate knowledge of tho snowfall
over the region in question. The patient and
honest pbcnrypP mn Iva tn h,r
faithful discharge of duty through several
years OF devotion. The civil engineer who
proposes to cOnfine the waters of a turbulent
Objectionable creek within walls of brick and
cement must first determine tho extent of
watershed drained by this stream and tho ex-
ueme amount OF rain and snow which may be
received on this shed in n given time.
in the construction of reservoirs to furnish
the water supply for cities the question of rain
fall is OF the greatest Importance in solution
oil the problem. The produce merchant buys
ana sells on the occurrence or chances Of rainfall
to Affect the price of agricultural products
Rainfall will affect tho supply of many streams
which are used for water-power and tho chances
OF Drumming the ills for an entire season depends
upon continuation Of the source of supply
low many anxious inquiries are made during
q protracted drouth when nature seems to
forget herselff On every hand search ia made
Tor information on which TO base an estimate
as to when the abnormal condition will termi-
nate. Reliable rainfall records for a long po-
rod OF time are Invaluable at such time
Examples in other directions, might be given
to show the great value of exact knowledge
concerning the distribution Of precipitation
AS this element of the atmosphere is extremely
local in its character there is especial need of
having every territory we'll covered with OBJ
serving stations.
The British Isles have over 1900 rainfall
stations, more than havo been reporting at any
one time in the whole United States
The proper apparatus for taking rain and
snow observations is very simple and consists
OF two cylindrical metal vessels described ms
follows: The standard rain gauge of the Signal
Service embraces three parts, viz: tho collector,
the receiver, and the overflow. The collector
is tuunei-shaped and eight inches in diameter
at the top. The receiver 10 cylindrical, 2.53
inches in diameter, and 20 inches deep The
overflow Is six inches in diameter and % inches
deep.
The standard snow gauge consists Of n oylin-
der eight inches in diameter and 20 inches
deep. The rain and suow-gRuges should DO
firmly placed on nearly level ground with the
supports arranged so that tho instruments will
be vertical and their collectors in the same
horizontal plane, and l2 inches above tho sur
lace OF the ground Tho point selected should
be at such distance from surrounding objects
that the tops Of such objects will not present
an angle more than the 45' elevation above the
gauges. When the gauges cannot DO placed on
che ground they may be located on the roof of
a building. and rs near the center of IL ms pos.
sible Cat roof affords tho best exposure
The amount Of rainfall Is determined by in
sorting vertically u measuring rod into the
receiver until IL touches the bottom Allow il
to remain moment aud then withdraw 10 and
read the number of inches and lOths the water
has wctted. The sectional areas Of the receiver
aud collector being l to 10, the depth Of
the water measured Is 10 times as much as
should be recorded. Therefore 10 inches of
wator in the receiver are equal to ono inch OF
actual raintall, and in the Same proportion for
smaller amounts. After the receiver has been
emptied the water in the overflow, if any,
should be poured into tho receiver, measured.
and added to that already found. In the case
OF snow that which is found in the gauge should
be melted and measured as water in the rain
gauge.