MOORE’S RURAL NEW-YORKER. 
AUG. S4 
Scientific mut ttoefut. 
INFLUENCE OF FORESTS ON THE FALL 
OF RAIN. 
This subject is at present attracting con¬ 
siderable attention, and the most contra¬ 
dictory opinions in regard to it find expres¬ 
sion in the public journals. The general 
impression on the public mind seems to be 
that forests do promote the fall of rain; but 
a few scientific men of high standing have 
recently opposed their authority to this 
popular view, and now the tide seems to be 
turning in the other direction, and the cry 
Is, •* Down with the forests, and lot them 
give place to grain, grass and roots.” For 
ourselves, wc have, no very high regard for 
” authorities,” considered merely as such, 
for we remember too clearly the notable 
mistakes that have been made by men of 
the highest, standing, when they have ven¬ 
tured opinions upon subjects with which 
they were not specially familiar. 
So, instead of taking the matter upon 
authority . let us see if there are any obvi¬ 
ous and well-known reasons for supposing 
that forests do promote the fall of rain. 
In all suoh oases the best evidence would 
be that of experience; but it unfortunately 
happens that in this instance it is very dif¬ 
ficult to find unimpeachable cases in which 
the grounds for supposing that the increase 
or diminution in the rainfall is due to the 
planting or removal of forest*, are clear and 
Indubitable. It is said that the present, or 
recent, famine In Persia is due to a severe 
drouth, caused by the fact that the removal 
of the trees has prevented the usual rain¬ 
fall. On t he other hand it is claimed t hat, 
drouths, though perhaps not of equal Re¬ 
verity, have been known for centuries in 
that couutr.y, and that between those 
drouths there have always been periods 
when abundance of rain has fallen. The 
Isthmus of Suez, too, Is a frequoutly cited 
case where the cutting of a great canal and 
the planting of numerous trees along its 
borders, has changed an arid and uninhab¬ 
itable country into one of prospective fer¬ 
tility. And in various parts of Europe there 
occur localities which tin* advocates of for¬ 
ests claim as striking instances of the effect 
of tree-planting upon the general climate 
and fert ility of the regions in which they 
He. It was thought that in our own coun¬ 
try there were soreral instances of this 
kind, and they have found a staple argu¬ 
ment in the hands of men who, like Hor¬ 
ace Greelet. are earnest advocates of tree- 
planting; but the Smithsonian Institute 
professes to have unimpeachable statistics 
to prove that the cutting down of our for¬ 
ests has had no influence whatever on the 
amount of our rainfall; and as the popular 
belief, that "figures cannot lie,” is very 
strong, this evidence has had great weight. 
We would, however, remind the dear public 
that so far from figures heiug the innocent 
and honest creatures which the above pro¬ 
verb claims, they are the most mendacious 
and deceitful things known to humanity. 
No inmate of our prisons will lie like a 
good honest set of figures. Put while we 
might oppose to t he statistics of the Smith¬ 
sonian Institute the equally valid, though 
perhaps not so numerically definite, data 
derived from the experience of good, hon¬ 
est men and women, who remember streams 
that in their youth poured a steady and 
considerable volume along their course dur¬ 
ing the entire year, and are now dry for 
three-fourths of the season and torrents 
during a large portion of the remainder of 
the year, it will probably be more satisfac¬ 
tory to take a plain and common-sense view 
of the notion exerted upon the at mosphere 
by troeB, and consequently of wbat must be 
their agenoy upon the rain-fall, provided 
the laws ot nature do not cease to act. 
The popular idea of rain i6 that it is a dis¬ 
charge from the cloud6, but this is not al¬ 
ways the case. Kaemtz, in his Treatise on 
Meteorology, tells us that showers have fre¬ 
quently been known to fall out of a clear 
sky, so that rain is in reality merely tin- 
watery vapor of the air, condensed and ag¬ 
gregated into globules of such a size that 
their weight causes them to fail rapidly. 
Now, it is familiar knowledge that all warm 
air contains water vapor; even the appar¬ 
ently dry air of summer days, when the 
earth is parched and dusty, contains mois¬ 
ture, as is made evident when it is brought 
into coutact wit h any very cold body, such 
as the outside of an ice-pitcher, in which 
case a rapid deposition of dow takes place, 
and the pitcher is, in common language, 
said to sweat. It is only very cold air that 
at all approaches dryness; and as the tem¬ 
perature increases, the_capacity of the air 
f or hol ding moisture increases very rapidly, 
Thus air at TO” Eah. can contain six times 
as much water as can be absorbed by ai r at 
the freezing point, or 32’. On carefully ex¬ 
amining the law which governs the absorp¬ 
tion of moisture by air, however, we find 
this very singular fact: that as the temper¬ 
ature of the air increases, its capacity for 
absorbing moisture, increases in a greater 
ratio. Thus, if we double the temperature 
of the air, its power of holding moisture in 
suspension will he more than doubled. 
From this it follows that, if we mix equal 
volumes of cold and hot air together, both 
volumes being completely saturated with 
moisture, a large portion of the moisture 
will be precipitated in the form of rain 
And this is a very frequent cause of rain 
showers. The air in a certain locality be 
comes not only heated but saturated with 
moisture, and begins to ascend. As it as¬ 
cends it expands and loses its power of 
holding moisture in suspension, and in ad¬ 
dition to t his a current, of cold air rushes in 
and mixes with it, thus still further reduc¬ 
ing its power of holding aqueous vapor in 
suspension, and consequently causing a pre¬ 
cipitation in the form of rain. Now, it is 
very obvious that there are two circuru¬ 
st ances, either one of which will prevent 
the formation of rain in this case. If the 
air, as it becomes heated, does not absorb 
moisture, that is to say. if the heating takes 
place over very dry ground, no moisture 
can be precipitated, for the simple reason 
that there is not enough to saturate the air, 
even at t he reduced temperature. The sec¬ 
ond circumstance which may prevent the 
formation of rain, is this: Jf the heated 
air be cooled by a current of cold but very 
dry air, the resulting mixture may he able 
to hold in suspension all the moisture that 
is present. 
The fact that air, as it expands, loses its 
capacity for retaining moisture in a state of 
invisible suspension, is beautifully shown 
during the exhaustion of moistened air 
from the receiver of an air-pump. As soon 
as a few strokes have been made the re¬ 
ceiver is tilled with clouds. Another illus¬ 
tration is frequently seen on close, warm 
days, when a dense cloud is sometimes seen 
to form over a moist locality and gradually 
expand aud enlarge until it. becomes wlmt 
is popularly known as a “ thunder-head,” 
and u storm of thunder and lightning fre¬ 
quently follows. Such clouds are undoubt¬ 
edly the beads of ascending columns of hot, 
moist air, in which the moisture is precipi¬ 
tated as the air gets into a higher region 
where the pressure is reduced. They can 
only be produced, however, where the as¬ 
cending column rises from moist ground so 
that it may be itself moist. 
In addition to these two causes for the 
deposition of moisture — cooling and ex¬ 
pansion— there is another which, though 
not generally accorded much consideration, 
is, we think, often quite as powerful as 
either of the others. This is electricity. 
Precisely how it acts wc do not pretend to 
say; but everyone who has observed the 
heavy fall of rain which almost invariably 
succeeds a flash of lightning, must acknowl¬ 
edge that the discharge of electricity from 
clouds is quite as efficient as the lowering 
of temperature. 
Let us now consider these general prin¬ 
ciples in so far as their agency may be af¬ 
fected by the presence or absence of frosts. 
In the first place, then, it is well known 
that all vegetables, trees included, perspire 
immense amounts of moisture, this mois¬ 
ture being frequently brought up from 
great depths. A single sun-flower plant 
has been known to exhale one pound four¬ 
teen ounces of water during twelve hours. 
Such being the case, what must be the 
quantity given off by all the leaves of a 
large tree, and what an inconceivable 
amount must be exhaled by auy one of our 
large forests? It is evident, therefore, that 
the air in the immediate vicinity of large 
forests must be much more moist than that 
resting upon dry soil. 
Another effect of this enormous evapora¬ 
tion must be a lowering of the temperature. 
All liquids when passing into the gaseous or 
vaporous condition, absorb and carry off 
heat, aud t he evaporation which we have 
noted must have a powerful effect iu low¬ 
ering the temperature of the air in the 
neighborhood of the trees. From this it 
follows that when a cool current of air flows 
over a forest the moisture will be precipi¬ 
tated iu the vicinity instead of being carried 
off, as it would be if present in smaller 
quantity. Aud when a warm aud very 
moist wind flows over a forest , the cooler 
air which is there present will cause a show¬ 
er of rain, whereas if there had been no 
forest and the air had been hot, the mois¬ 
ture would have been swept onward to 
other regions. 
But perhaps the most powerful effects are 
produced by the action of the forests in dis¬ 
charging the electricity which is almost 
always present in clouds, and thus produc¬ 
ing a rainfall. That, trees do act in this 
way Is well known and easily proved. 
Noad, in his large work on elect ricity says: 
“Living vegetables are the most powerful 
conductors with which we are acquainted. 
Mr. Week eh found that a coated jar, hav- 
forty-six inches of metallic surface, was re¬ 
peatedly discharged by the activity of a 
vegetable point iu four minutes and six 
seconds, while the same jar, charged to the 
same degree, required eleven minutes and 
six seconds to free it from its electric cur¬ 
rents by means of a metallic point—the 
points in bot h oa^o* being equidistant. The 
same gentleman also found that the gold- 
leaf electroscope is powerfully affected by a 
jar at the distance of nearly seven feet., 
when the cap of the instrument Is furnished 
with a branch of the shrub called butcher’s 
broom, though the same instrument, when 
mounted with pointed metallic wires, is 
not perceptibly affected until the charged 
jar approaches to within two feet of the 
cap. 
“ If a blade of grass and a needle be hold 
pointing towards the prime conductor of a 
machine, while the person.holding them re¬ 
cedes from the instrument, a small, lumi¬ 
nous point will appear on the apex of the 
needle.” These experiment,s show conclu¬ 
sively that forests are powerful agents in 
discharging any electricity that may be 
present in such clouds as may pass over 
t hem, and we have every reason for believ¬ 
ing that whenever this electricity is dis¬ 
charged a rainfall will occur. 
In discussing this subject, we have en¬ 
deavored to avoid the introduction of all 
questionable theories, and to rely upon well 
know and t horoughly ascertained physical 
facts aud laws. For the present, at least, 
we would regard the evidence derived from 
this source as of more weight than any t hat 
can be furnished by mere statistics, until 
the latter have become far more general 
and extended over a greater time than is 
yet the case. j, p. 
-- 
SCIENTIFIC AND USEFUL NOTES. 
<§)mtt$»ik dkMomij. 
WORKING UP BEESWAX. 
The old-time practice of the wholestile 
destruction of a colony of bees when the 
honey was to bo taken, has been consider¬ 
ably reformed in view of t he fact that it is 
poor economy to kill the goose which lays 
the golden egg; and the wholesale destruc¬ 
tion of honey comb has been stopped, as it 
has been discovered that it is largely eco¬ 
nomical to supply the old comb to other 
hives to help young colonics to set up in 
their housekeeping. Still there will be 
comb to be made into wax, and it is well to 
know how to make t he most of it. 
A pound of common beeswax in the lump 
is worth, say thirty-five cents, and a pound 
of bleached wax is worth, in the lump, 
twice as much. When maple sugar first 
appears in the early spring, you will see it 
sold iu neat little cakes at. the rate of sev¬ 
enty-live cents to one dollar a pound, when 
the price in the lump is twenty-five cents. 
Ho wit h beeswax; taken parcel of salt-collars 
and cast little cakes of wax, sixty to the 
pound, and sell those at five cents a-piece. 
Before casting the cakes of wax, prepare a 
lot of silk ribbon loops, which will serve to 
hang the cake of wax by, and as the wax is 
poured into the moulds, lay the ends of the 
loop iu the edge of the mould so it will stick 
well in the wax, and j’ou have a neat and 
salable little article which will fetch very 
much more than the same material in the 
lump. 
--- 
ODDS AND ENDS. 
Domestic Inquiries. — Mrs. Jane M. 
Adams asks some one to tell her how to 
make elderberry wine . . . . L. W. L. asks 
for directions how to make a shirt to fit in 
every instance. Janie f). asks for a 
recipe "for making pepper sauce that will 
equal the Worcestershire sauce.” [Can't, be 
done.— Eds.1 .... Meiiitaiilk and Hkp- 
zniAu Livingstone ask for a recipe for 
making citron cake and Welshrare-bits. . . 
Emma R. Bin oos asks for the best recipe 
for making cucumber pickles in vinegar. 
Monograms. — The correspondent who 
Cloelt-Work to Raise Water.—Would 
a machine constructed on the order of 
clock-work, and run by a weight, raise 100 
gallons of water, in 34 hours, from a well 
feet, deep, to a point 10 feet above the 
ground, said machine to run for 24 hours 
without being wound up more than once? 
If bo, what would be the arrangement of 
the wheels to do the required work? By 
answering in Rural New-Yorker at an 
early day you would confer a favor on 
constant reader.— B. Smith. 
We advise our correspondent to send the 
above inquiry to some technical paper 
suoh as the Scientific American, American 
Artisan, or Handicraft (all of New York 
City), whose editorial corps embrace tech¬ 
nologists familiar with such problems. 
Meantime, we publish the inquiry, so that 
any of our correspondents familiar with 
such questions may answer, if they choose 
to do so. 
"TheSiphon Again.”—We, too, “would 
like to know whether Old Subscriber, who 
had a troublesome siphon, succeeded iu 
making it work; aud, if so, bow he over¬ 
come the difficulty." A. J. thinks one of 
our reasons why it might not work "rather 
thin.” If A. J.’will take the trouble to ex¬ 
periment, as well as theorize, he pi’obably 
will not expose bis ignoranoe by saying. “ it 
makes no difference if the well end of the 
pipe is two inches, and the down bill end 
one-fourth inch, or vice versa.” We know, 
from experience, that it is essential that 
the pipe be of a uniform size, and that the 
outlet be the same size as the balance of pipe. 
—11. H. S. _ 
Revelations of the Microscope. — A 
scientific journal says:—The microscope re¬ 
veals to us the fact that the surface of our 
bodies is covered with scales, like a fish; a 
single grain of sand would cover 150 of these 
scales, 'and yet, a scale covers 500 pores. 
Through those narrow openings the sweat 
forces itself, like water through a sieve. 
Expressing Oil from Castor Bean.— 
L. T. Van T. is informed that, so far as 
our knowledge extends, a screw press is 
usually used for expressing the oil of this 
beau. We have seen an ordinary eider press 
used. 
asks for certain monograms will find them 
furnished herewith. 
To Drive Away Ants.—We were much 
troubled this season by having large black 
ants find their w ay to our sugar box wtaere- 
ever we could place it. Remembering to 
have read somewhere that the common 
elder would keep ants away from anything 
about, which it was placed, I gathered an 
armful of the young sprouts aud put them 
around the box. We have not siuoe been 
troubled in the least by them.— E. E. Tut¬ 
tle. 
Pop-Corn Balls,—I make pop-corn balls 
by pouring the sirup made by melting 
white sugar upon the popped corn, and 
working it with the hands to the dcsirod 
shape aud size. Afterwards roll the balls 
in sugar sand of various colors. These 
please my children greatly, though there 
may be a uioer way.— Mrs. C. G. Smith. 
To Exterminate the Paper Moth.— 
I think they are not confined wholly to 
paper. I have tried pulverized borax, 
sprinkled on dry, which seems to effectual¬ 
ly “ (Ms-tinguisli" them, as the man said 
about the fire. You can take your own way 
in making them eat it.— Mrs. E. S. T. 
Recipe for Making Artificial Oysters. 
Cut from the cob green corn enough for a 
pint; to this add one egg, well beaten, one 
cup of flour, half cup of cream or butter¬ 
milk; salt and pepper them to taste; fry 
in butter.— Frank G. 
• ^— 
To Remove Iron Rust.—Saturate the 
rusted spots with lemon juice and spread 
the linen in the hot sun. If it is not re¬ 
moved the first time, repeat the process un¬ 
til the result is satisfactory.—M rr. W. L. B. 
To Remove Iron Rust from White 
Linen.—Apply lemon juice and salt; put it 
in the bright sun for a time—one or two ap¬ 
plications if pecessary. 
