Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1881-08-08
THE STATISTICS OF RAINFALL.

lished table showing the amount Oh ram
fall, by months, years and seasons, from
IS49 to 1850 81 inclusive. This is the
completest tabular exhibit of the kind hith-
erto published. 1t is compiled from the
meteorological records of Drs. Logan and
Hatch and the Signal Service Bureau, and
it may be relied upon as accurate. perhaps
with the single exception of the statement
for the first year (lS49), when there was no
careful observation made. An examination
Of this table goes far to demonstrate the
correctness of the theory that the rainfall
in this State is governed by laws which |
bring about a maximum and minimum fall |
generally within cycle of seven years.
Three such seven-year cycles are distinctly |
shown by the season statistics. Sometimes
the cycle appears to be completed in six
years. There is of course nothing like alb
solute uniformity in the succession, but
taking one year with another the general
average sustains the theory. In the three
first cycles, starting with the year 1850, the
seventh year was that of minimum rainfall.
In the fourth cycle the sixth year brought
the minimum The present is the fifth
year of the fifth cycle, and therefore it may
reasonably be concluded that we shall not
have dry season for two years more. It
is also to be noticed that while in few in
stances the transition from abundant to
very restricted rains has been sharp and
sudden, the rule seems to be gradual de-
cline in the amount of rainfall. Thus in
1858 we had q inches in 1854, l6 inches
in 1855, IA inches, and in 1856, 10 inches.
In the food season of 1861 CO the fall was
50 inches. The next year it descended to
i inches, and the minimum was reached
the third season after the food, when it
fell to less than S inches
In lS67.S the fall was nearly 33 inches.
The following season it was II inches. The
| next dwindled to l6 inches, and then came
a dry year, with only 9 inches. The sue
coeding cycle was marked by a greater
! evenness of rainfall in the first four years,
and more sudden and abrupt descent.
The figures were %, II, %, %, 20, and 9.
The last four years have been "a, Is, &c,
&c, showing somewhat similar evenness of
fall, and this may be regarded as indicating
a possibility that the present cycle viii be
one of six years instead of seven, though
of course all such conjectures are merely
in the nature of guesses. But the table
we have published certainly does warrant
the conclusion that comparatively dry
year must be expected every sixth or
seventh year. and that such an expecta-
ton is net merely a superstition, but the
natural conclusion to be derived from a
careful comparison of the rainfall over a
period of thirty years There is in fact no
recorded instance of more than seven years
at a time OF sufficient rains, and while no
doubt an examination of the records of
much larger period would be necessary to
| establish this conclusion as a settled law of
nature, the presumption that the condi-
tions are such as to bring about the
changes shown in about the periods stated,
and with few Irregularities, is certainly
warrantable.
This table further fortifes these opinions
By showing that the meteorology of Cali
fornia is for the most part remarkably uni
form and regular. The months which are
called dry are usually completely dry. The
months in which sprinklngs of rain occur
rarely exhibit anything more than such
sprinklings. Thus if we take July, Au-
gust and September, we find that in thirty
years the greatest amount of rainfall in any
one month was one inch. a similar stesdi-
ness during the majority of the years is to
be noted in wet months, the maximum and
minimum years being of course excepted.
But the principal Importance of these rec
ords consists in the encouragement they
afford to the belief that it is possible, with
comparatively little risk, to predict the ap-
proach of the dry years, and thus to guard
against them in many ways. 1t may not
be possible to say whether the sixth or the
seventh year will be one of minimum rain.
| fall; but so far one of these years has
always been dry, and in three cases out Of
four it has been the seventh year. If we
may judge from the past, therefore, it
would seem safe to predict that the coming
winter viii be one of moderate, but suffi-
Gent, rainfall, and that there will. be less
rain than in the last season. The succeed
ing season may be that of minimum rain.
fall, or it may be the one preceding dry
year. In either case the probability is that
! there will be less rain than in 1881 ..
With this table before them cur farmers
ought to be able to study the signs of the
weather to better purpose than heretofore
OF course it must be thoroughly under
stood that absolute dependence cannot be
placed upon the records OF so compare
lively short period as 30 years. If we
had the statistics Of century to guide US
there would be no difficulty in coming TO
determination as to the cycle theory, but
it must be realized that in Nature there
are often cycles within cycles. For ex-
ample, it might prove to be the law that
certain phenomena should persist in regu-
lar graduation for five or more cycles OF
seven years each, and that then an equally
well established change should occur. The
existence OF these broader laws can only be
discovered by the examination OF much
longer periods than we have any authentic
record OF in the present case, and
therefore we are obliged to pro-
coed very cautiously with our gen.
Civilizations All the knowledge at our
disposal certainly tends to establish the
seven-year cycle hypothesis, and as
working theory it viii be safe enough to
hold it until something shall occur to
indicate the interference of laws of which
we have had no experience thus far. If
the ensuing season, for instance, should hs
a dry one, it would be the first time in
thirty years that dry year has occurred
on the fifth year, and therefore we are
,o1 HI, A