New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1874-10-05
APPLIED SCIENCE.

BRONzING WoOD.-Saturate the article first with
hot parchment glue previously filtered and not too
weak: and when dry, coat while slightly wafh''
with red ochre mixed with little yellow, ana when
perfectly dry coat second time. Then run 'he
whole carefully with moistened shave-gEass' anu
apply, with q bristle-brush, the bronze Oh copper
and brass or tin, mixed with alcohol Inc arucie
O. we'll as the bronze, must be kept warm during tne
Operatiop either in the sun or near hre Two OF
three coats are necessary TO produce perfect eject
VIBRATIONS OF LIQUID SURrACEs.-The updula-
tions which are produced upon liquid surfaces when
= heavy tuning fork is brought into contact with
the vessel containing the liquid, have been investi
gated by Barthelemy. He observed the phenomena
BY allowing beam Of sunlight reflected from the
liquid surface to fall upon screen. Barthelemy de-
duces the two following laws for rectangular yes
sells First that the breadth of the fluctuations is
inyersey as the number of vibrations, and second,
that the distance between two lines produced by the
same tuning fork is independent of the density OF
the liquid. The author calls attention to the gen.
era resemblance of these surfaces in the basin
Of fountain to the waves of the sea even IN the
sand on the sea beach they may be recognized; SO
also clouds often arranged in parallel bands ana
ingenious application Of these facts accounts for
the phenomena OF straitcatiOn produced by eiectrc
discharges In rarited media
PROTECTING INFLUENCE OF THE EARTH's AT
MOsPHERE-Weilmann after reducing the hourly
ebsery ations made at Berne Switzerland for seven
years. and deducing therefrom the laws OF diurnal
change of temperature, has investigated the innu-
ence of cloudiness on the daily variation, especially
ut night He finds that the radiating power OF the
earths surface is everywhere and at all times the
same. The temperature IN the morning Is. he hnds
in cloudy weather five six degrees higher than In
clear weather. Aud, again, that the simple atmos-
r Al l. 10 varnfa tim
layer of Clouds and that without this the earth
would experience daily an enormous variation in
temperature. Even the clear sky, or rather the
moisture present as an invisible vapOr protects the
earth with an efficiency equal to about One-thrd OF
that exered by layer of Clouds against too strong
daily change of temperature.
ELASTIC REACTION BY TORsION.-From a COM
muncation by DR.. Nessen presented to the Academy
of Sciences of Berlin by Helmholtz it appears that
the former has been investigating the reaction OBJ
served after twisting string of India rubber. This
substance is peculiarly interesting. because OF its
remarkable combination of the properties OF
viscosity and elasticity. The observations of DIR.
Nessen, made with apparatus of considerable
delicacy, lead to results somewhat different from
those of Kohlrausch. He finds the strings observed
to be highly susceptible TO the least radiation of
warmth: but, avoiding this source OF error,
he concludes that the elastic reaction IN the case of
torsion follows the law expressed by simple
expOnential curve. The magnitude of the reaction
increases with the diminutOn of temperature, as
also with increasing angle of tOrsiOn and with IN
rreasing duration to time. The cOefficlent OF
elastic reaction increases with increasing tempera
ture only, being independent OF the extent oil the
duration OF the torsiOn
KEEPING GRAPES FREsH.-A method of preserving
grapes for long time. even from one Autumn until
the next Summer, has come into extensive use. The
grapes are kept OH the vine as long as pOssble-ln
France, where this device originated, to the end OF
October or beginning of November. Before the first
frosts appear they are cut leaving portion OF the
stem of about two or three knots below the bunch
and two above it. The section of the upper end is
then to be covered with wax. to prevent the evapO
ration of the liquids contained in the pores of the
wood; and after carefully removing all the unsound
grapes the lower end of the stem is inserted in
small elongated bottle filed with water, having
small quantity of wood charcoal in the bottom. The
space between the stem and the tightly fitting cork
through which il is inserted is to be filled up with
The bottles thus fitted TO be placed on
shelves IA dry room and there arranged so as not
to fall over, this being best prevented by inserting
them in holes bored in frame as close together as
they can stand conveniently.
ENGLISH ENAMEL FOR CAsT-IRON.-A brilliant,
white, and very adhesive enamel is formed on cast
iron articles in the following way After heating
them to ed-heat in sand, and keeping them thus for
half an hour they allowed to cool slowly, and
then carefully cleaned with hot dilute sulphuric or
bydrochlOric acid rinse d with water and dried
ground is then laid by coating them with the fol-
lowing mixture, afterward drying them at high tenn
perature and then heating them in separate muffles
TO vitrhcaton of the coating: parts of flint glass;
B of borax, of minimum. l of oxide of zinc mixed
and finely pulverized, and heated for four hours up
TO red heat and finally rendered semi-fuid by in
crease of temperatures the mass is then quickly
quenched in cold water and one part of it is mixed
with two parts of bone meal and formed into pap
by triturating finely with sufficient water. Upon
this ground the two following mixtures, prepared
like the first then laid i'll succession. the first of
81 parts of cacined bones 6 of kaon IA of fedspar
of potash stirred up with water, dried, calcined
and suddenly cooled in water, aud the powdered
mass tr1turated with water TO q fine paste with 16
parts of flint glass 81 of calciGed bones and of cal
cined quartz; after this has been laid on and well
dried a second coating is laid on of parts of field
spar of pure sand of potash. of bOraX of oxide
of zinc of satpeter / of white arsenic l of the
best chalk; these ingredients mixed, calcined
suddenly cooled in water and trlturated with 81
parts of calcned bones and of quartz. The dried
article is finally heated in mufe, in furnace sim
liar to a porcelain furnace, when both coatngs fuse
and mix thus forming the enamel.
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