Juniata sentinel and Republican. [volume] (Mifflintown, Juniata County, Pa.) 1873-1955, 1880-12-08
Tn. Enec. orrorests Upon Rainfall.

The effect of clearing land of Its trees,
according to the opinion of many meteoro-
logists, engineers, and other scientific stu
dents of the subject, is to diminish the av.
erage rainfall of the country thus cleared,
to lessen the outflow of the rivers, and also
to cause such concentration of the amount
of rain and snow within short periods as to
increase the danger Of floods to a marked
extent. This theory was formulated most
fully in 1878 by Sir Gustav Wex. chief en-
gineer of the Improvements in the Danube
River at Vienna, who supported his opinion
by very ample calculations as to the de-
crease in the volume of water discharged
by the five principal rivers of Central Eu.
rope. Since that time many opinions have
been expressed by experts, some affirming,
others denying, the correctness Of Sir Gus
tav's theory; some have claimed that the
fact of such decrease in the discharge OF
the rivers cited has not been satisfactorily
established; while others, admitting that
the decrease has gone on, deny that this
fact is sufficient to prove the accuracy of
all, or even any Of Sir. Gustav's conclu-
sions. The latter has, therefore, recently
published second treatise, in which he
says that for six years he has Stunned nei-
ther labor nor expense in obtaining as many
and as reliable technical hydraulic meas
urements and data of different streams as
possible; and he has come to the conclu-
sion that his theory has been proven to be
correct.
Sir Gustav gives voluminous tabular ex-
hibits of observations taken on a number of
large rivers extending over periods of more
than 100 years in some cases, and in nearly
every case it is found that the river surface
has been lowered 10 marked degree. The
rivers citedare the Upper and Lower Rhine,
the Danube, the Elba, the Vistula, the
Oder, the Moselle, the Main, the TheIss,
the Tiber, the Po, the Seine, the Glommen
On Norway and the Mississippi. In reply
to the objection that the lowering of ri
ver's surface may be due to the deepening
OF its channel, and not to the decrease in
the volume of water discharged, Sir Gus
tav admits that the channel beds are some
times raised and sometimes lowered; ''but, !"
he says, ''if from the numerous gauge
readings submitted By Inc are eliminated
those which were taken on stretches of the
stream in which changes in the bed of the
river took place, we will still find some
rivers or stretches of stream which lie either
in a natural unchangeable bed, or which
have been improved from time immemori-
al and are IN permanent condition. The
most scrupulous expert must admit that on
such rivers and stretches we can Justly as
sumo that the decrease in their stages
4. C., the sinking Of their surface, indicates
a decrease in their volume of water, since
it would be impossible to explain the phe-
nomenon in any other way.
Sir Gustav claims that the destruction
of forests, necessarily coincident with the
advance of civilized habitations into new
countries, not 1nly diminishes the aggre-
gate amount of rainfall, bnt it increases the
tendency to floods. This is, of course,
equivalent to saying that the rainfall (Which
word includes all atmospheric aqueous de-
posit, sucn as rain, snow, hail, dew, etc.
is concentrated into briefer spaces of time,
during the year, instead of being equally
d stributed; and as this concentration mu
have detrimental influence upon agrI-
culture, the importance OF the subject ex-
tends beyond its effect upon rivers alone,
which is the only point of view taken by
sir Gustav Wex. 1t therefore deserves
double attention in this country, where
droughts are so often such serious causes
of crop failures
The observations of the Mississippi re-
corded by Sir Gustav were made at Nat
chez, Miss, and extended over period of
III years. They showed mean annual
fall of seven-tenths of an inch in the sur
face level of the water, while the highest
stages averaged nine hundredths of an
inch higher each year, and the lowest
stages thirty nine hundredths of an inch
lower each year.