Scientific American Supplement, No. 392, July 7, 1883
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Various >> Scientific American Supplement, No. 392, July 7, 1883
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[Illustration: SCHMID'S WATER METER.]
* * * * *
WASHING MACHINE FOR WOOL.
The washing machines in use for wool on the rake principle have during
the last few years experienced many improvements in the details of
their arrangement, which we have illustrated at different times in our
columns. The introduction of these improvements and alterations shows
that the washing of wool has attracted more attention on the part of
observant manufacturers and machine makers, and demonstrated at the same
time that the machines hitherto in use, with all their advantages, left
much to be desired in other respects. The main difficulty with all
washing machines for wool has been the avoidance of felting of the wool,
which tendency is increased by the use of warm water for washing and by
the agitation that some consider necessary for a thorough cleansing of
the wool and removal of the adhering impurities, but which agitation is
deprecated by others.
[Illustration: IMPROVED WOOL WASHING MACHINE.]
Referring to our different illustrations of improvements in this
direction, our subscribers will observe that the tendency of all these
has been to keep the wool floating in the water, and to apply all
mechanical appliances required for its cleansing and pressing as much as
possible while it is in this suspended condition. The success which the
different appliances and improvements mentioned by us have had when used
for the class of wool for which they are intended, has induced us to
look up any attempts in a similar direction which have been made on the
Continent, where the subject has attracted attention, as well as with
us. We therefore give the annexed illustration of a machine invented by
a German woolen manufacturer, which in many respects is a wide departure
from the acknowledged type in use in this country. As with the English
machines, the wool enters from a creeper at one end, passes through a
long trough, filled with water or lye, ascends an inclined plane, and
passes out through a pair of squeezing rollers. The invention mentioned
applies to the treatment in the trough which latter is shown in our
illustration at K. It has a second bottom, a little distance from a
false one, at K. The false bottom is traversed in its whole length by
an air pipe, communicating with the atmospheric air outside the trough.
From this longitudinal pipe other pipes branch off at right angles at
stated intervals, as shown in section in Fig. 2. These smaller pipes
contain a number of small perforations on their upper part, through
which the air ascends into the water in innumerable small bubbles. This
is one of the principal aims of the invention, for in ascending the
bubbles lift the wool more or less to the surface and tend to open it
out without the risk of doing so by any mechanical means liable to
produce felting. This is the same effect that is produced in many cases
so successfully in boiling. Instead of rakes the inventor has placed
four hexagonal drums into the trough, marked D, E, F, G. The flat parts
of these drums are made of perforated metal and set back a little. This
produces an alternate passing of the water into and out of them during
their revolution and consequent sucking and repulsing of the wool, which
also likewise agitates it. These drums are made wide at the entrance end
of the trough and gradually narrower toward the delivery end. The pipe,
V V, is the usual steam pipe for heating the water.
We have said before that the improvements introduced into the wool
washing machines nearer home have been of advantage for the wools for
which they are intended, and possibly the invention just described will
also be valuable in some cases.--_Tex. Manuf._
* * * * *
INCREASING THE ILLUMINATING POWER OF GASES, ETC.
By V. POPP, of Paris.
This invention relates to lighting by mixing air or other gaseous
supporter of combustion with illuminating or other hydrocarbon gas or
vapor, and burning the mixture (at a suitable pressure) in a burner of
special construction, shown in the accompanying illustrations.
[Illustration]
The burner is constructed as shown in Figs 1 and 2. It consists of a
central tube, i, screwing upon the pipe by which the gaseous mixture is
supplied. Upon this tube is screwed a cup, k, of metal or refractory
material which supports a cap, l, of fire-clay in the shape of a thimble
(or of other form, according to the intended use of the burner). The
flanged base of this cap is perforated with a ring of holes, m, as small
and numerous as possible, and the sides of the cap are pierced with
oblique perforations, n. The top of the tube, i, is provided with four
small projections, upon which rests a copper cone, o, soldered to the
tube at a point below the perforations in the base of the thimble. The
cone is perforated at its lower end with small holes, p, the sum of
whose areas is at least equal to the area of the tube. The thimble,
l, is surrounded by an envelope, q, of platinum wire netting or other
refractory material of the same form. The gaseous mixture arriving by
the pipe, i, escapes at the upper orifices, r, and passes down against
the interior surface of the cone, o, out at the orifices, p, and escapes
through the orifices in the cap, l, at which it is burned. The cap is
thereby raised to a high temperature; and the platinum wire sheath
becoming incandescent radiates the light. The gaseous mixture, by coming
first in contact with the copper cone and then with the refractory cap,
becomes raised to an exceedingly high temperature before it is consumed.
In the modified burner represented in Fig. 3, the metal cone and the
fire-cap are truncated. The tube, i, is provided with a number of small
perforations, r, at its upper end, the sum of whose areas is at least
equal to the area of the tube, and by which the gaseous mixture is
distributed within the chamber, k. Upon the upper closed end of the tube
is fixed a cup or inverted thimble, o, of fire-clay. A refractory cone,
l, surrounds this cup and rests by its base upon the cup. This flanged
base is perforated with small vertical holes, m, and upon it is fixed a
platinum wire cage or envelope, q. An annular space is left between the
cone and cup for the passage of the gaseous mixture, which, on escaping
from the orifices, r, passes over the exterior surface of o, the
interior of which is already heated by the flame which has not passed
through the wire gauze, and has been forced by the pressure of the
mixture into the interior of o. The gaseous mixture before passing
through the annular space thus attains such a temperature that on
escaping from the orifice its combustion is greatly promoted.
* * * * *
PREVENTING IRON FROM RUSTING.
In the present state of civilization the use of iron has reached a very
wide extension, and in a great number of cases iron is used where wood
or stone was formerly used. It is certainly an important question how
this metal can be protected under all circumstances against rust or
oxidation, so that the many costly iron structures may retain their
usefulness and strength, and be handed down uninjured to posterity.
Wherever bright iron comes into contact with air and moisture it
immediately begins to rust, and this rust is not content to continually
rob it of its substance in its persistent progress by scaling off the
surface, but at the same time it injures the remainder of the iron by
making it brittle. Attempts have hitherto been made to protect the iron
by covering it with other and less easily oxidizable metals. For this
purpose tin was first selected, then lead and zinc, and recently nickel.
Furthermore, earthy glazings and enamels, such as are used on stone
ware, have been applied to iron vessels, and they have already found
extensive use in the household. In most cases these coatings, either
metallic or vitreous, are inapplicable, either because they cannot be
applied or are too expensive, so that on a large scale recourse must be
had to paints made by mixing oils with metallic oxides, earths, etc.,
for protecting the surface of the iron from air and moisture.
It has been observed that iron does not rust in _dry_ air, not even in
dry oxygen. In like manner it frequently happens that unpainted iron,
such as weather vanes, fences, etc., is exposed to the air for a century
with very little injury, being covered with a thin coating of the
magnetic oxide (proto-sesquioxide), which acts as a protection and
prevents farther action. Hence it has been proposed to produce a layer
of this magnetic oxide on the surface artificially, and it was found
that superheated steam furnished the means for doing this. But it is not
to be supposed that such a process would find use on a large scale, and
besides this protection could only serve for iron tolerably exposed to
the open air and not for that in direct contact with carbonic acid and
water.
An interesting observation has been made on railways that the iron
rails, ties, bolts, etc., rust until the road begins to be used. Here we
must assume that anything made of iron is more inclined to rust when at
rest than if occasionally caused to vibrate, when an electrical action
probably comes into play and decreases the affinity of iron for oxygen.
In tearing down old masonry iron bonds and clamps are often found which
are as free from rust, so far as they are covered with mortar, as they
were the day they left the blacksmith's hands. A French engineer met
with such a phenomenon when he uncovered the anchor plates of several
chain bridges which had been built about thirty years. Where the anchors
were covered with the fatty lime mortar of the masonry they showed no
traces of rust, but the prolongations of the anchors in empty spaces
were rusted to such an extent that they were only one-third of their
original thickness.
It has been repeatedly observed that iron does not rust in water in
which are dissolved small quantities of caustic alkalies or alkaline
earths, which neutralize every trace of acid. It seems that these
experiences are the basis of A. Riegelmann's (Hanau) new protection
against rust. The paint that he uses contains caustic alkaline earths
(baryta, strontia, etc.), so that the iron is in a condition similar to
the iron anchors of the chain bridges that were embedded in lime mortar.
Although a paint is not thick enough to inclose so much alkali as the
masonry did that the iron was embedded in, nevertheless the alkaline
action will make itself felt as long as the coating has a certain
consistence. Under all circumstances, however, these new paints will
be free from active acids, which is more than can be said of our iron
paints hitherto in use. Besides this, the rust protector has such
a composition that it could serve its intended purpose without the
addition of any alkali. If experience confirms this claim, it will be an
interesting step forward in the preservation of iron, and contribute to
an extension in the use of iron.--_Polytechn. Notizblatt_.
* * * * *
[Illustration: SUGGESTIONS IN DECOTATIVE ART.--A CUPBOARD IN ITALIAN
WALNUT WITH DARKER PANELING.--_From The Workshop_.]
* * * * *
AN ELASTIC MASS FOR CONFECTIONERS' USE.
It should be made in a well glazed earthen crock; metallic vessels are
not good, as the gelatine burns too easily on the sides, and dries
out where it gets too hot. Nor is a water bath to be recommended for
dissolving the gelatine, for the sides get too hot and dry out the
gelatine.
A quart of water is put in the crock and heated to boiling; it is then
taken off the open fire and two pounds of the finest gelatine stirred
in, a little at a time. After the gelatine is completely dissolved there
is to be added eight or ten pounds (according to the quality of the
gelatine) of the finest white sirup previously warmed, and constantly
stirred. The mass must not boil, as it would easily burn, or turn brown
and acquire a bad color.
Thirty or forty pounds of a beautiful white elastic mass can be made by
this recipe in an hour at a cost of ten or twelve cents. Its chief use
is for making figures and ornaments to put on bridal cakes and other
fanciful productions of the confectioner. It contains no harmful
ingredients and can be eaten without danger. If coloring is added,
cochineal, plant green (chlorophyl), and turmeric are safer than aniline
colors.
* * * * *
CAOUTCHOUC.
A. Levy contributes the following brief account of this subject to the
_Moniteur Scientifique_:
The crude gum cut in irregular strips is passed five or six times
between two strong rolls sixteen inches in diameter, and making two
or three revolutions per minute. These rolls are kept wet by water
trickling on them. This broad strip of gum is perforated with foreign
substances and looks like a sieve. It is next put in the cutting
machine, a horizontal drum provided with an axle having knives on it. So
much heat is produced by this cutting that the water would soon boil if
it were not renewed. A second machine of this kind completes the cutting
and subdividing, and expels the air and water from it. The mass is then
pressed in round or quadrangular blocks.
The vulcanization of thin articles from one twenty-fifth to
one-sixteenth inch thick, is done by Parkes' patented process, that is,
dipping it in carbon disulphide for a short time, to which chloride or
bromide of sulphur has been added, and when the solvent has evaporated
the sulphur remains behind. Balls, ornamental articles, and surgical
apparatus are dipped into melted sulphur at 275 deg. or 300 deg. Fahr.
The third most important process consists in mixing in the sulphur
mechanically with the gum in the cutting machine.
After the pieces have received the form they are to have they are heated
with steam or hot air to 275 deg.. Flat articles are vulcanized between
press plates heated by steam. This vulcanization is said to have been
discovered accidentally by searching different colored stuffs, some of
which were dyed yellow with sulphur; the latter stood well.
Hard rubber contains more sulphur, and is heated longer and higher.
Small or fine tubes and hose are made by a continuous machine that
presses it through a hole with a core to it. Large hose is made by
wrapping strips around iron rods or tubes. The little air balloons
are made in Paris (their value is $300,000) by Brissonet from English
Mackintosh cloth. Powdered soapstone is strewed over it in cutting. The
edges are united by hammering on a horn anvil, or by machinery through
simple adhesion, and the cut surfaces are smooth.
* * * * *
PHOTOGRAPHIC ACTION STUDIED SPECTROSCOPICALLY.
At the last meeting of the Chemical Society Captain Abney gave a lecture
on the above subject to a large audience. We may premise by saying that
the demonstrations he gave were carried out principally by means of
experiments on paper, to enable his hearers to understand the different
points he wished to enforce. The lecture was commenced by insisting on
the fact that all photographic action took place within the molecules of
the compound acted upon and not on the molecule itself, and from this
he deduced that the absorption of radiation which take place by such
compounds is principally caused by the atoms composing the molecule.
This was found to be the case in the organic liquids, which the lecturer
to some extent had investigated, where he had further traced the
absorption to the vibrating atoms of hydrogen in those bodies. In
order to properly investigate the action of light it was necessary to
ascertain which components of light in the spectrum were the chief
agents in causing it, and this led him to consider the means to be
employed to obtain a spectrum.
The effects of diffraction gratings were first discussed, and in two
which were shown it was found that in some spectra the visible portions
were dimmed; in others the ultra-violet and the infra-red were almost
entirely absent. It thus became necessary to investigate the condition
of a grating before placing any confidence in the results obtained. This
was the first pitfall into which an experimentalist was liable to fall.
If prisms were used for obtaining the spectrum, then precautions had
also to be taken, since all glass absorbed a portion of the ultra-violet
rays and some the infra-red. On the whole, he considered that the best
glass to use was pure white flint glass for the collimator, the prisms,
and the camera lens. Another inquiry that was necessary was the
source of radiation which it was proposed to use. Diagrams showed the
unsatisfactory nature of solar radiation, and a photograph of the whole
spectrum, taken with it under certain atmospheric conditions in which
the effect of the green rays were almost _nil_, demonstrated the false
conclusions that might be deduced as to the sensitiveness of any
particular compound.
Captain Abney also showed the satisfactory conditions which existed in
using the crater of the positive pole of the electric arc light as a
source, and by diagrams illustrated the inferiority of an incandescent
light for the purpose, owing to the deficiency of violet and
ultra-violet rays. Having thus settled the source of illumination and
the kind of apparatus to employ, he next considered the conditions under
which the sensitive salts were to be exposed. The action of ordinary
sensitizers was explained and demonstrated by experiments, from which
point the results of certain colored sensitizers were considered. Thus,
various aniline dyes were proved to be bromine absorbents, and likewise,
more or less, to be capable of being acted upon by light in those
regions of the spectrum they absorbed. The result of the two effects was
to produce a developable image of the spectrum just in those parts to
which the salt of silver was sensitive, and also in the parts where the
dye itself was acted upon. The latter effect was traced to the organic
matter being oxidized in the presence of the sensitive silver salt.
The sensitizing effect of one silver compound upon another was then gone
into, and experiments and photographs showed where two salts of silver
were in contact with one another, and without an energetic sensitizer
being at hand, that the one when acted upon by light absorbed the
halogen liberated from the other through the same cause and that a new
molecule was formed. This was of importance, since in photographic
spectroscopic researches a conclusion might be arrived at that a
body suffered absorption in those regions of the spectrum where this
interesting reaction took place, whereas in reality the phenomenon might
be due to the silver salts employed. This was another pitfall for the
unwary. Again, it became necessary in studying photographic action to
make sure that the effect of radiation was only a reducing action, and
that the results were not vitiated by some other action.
The destruction by oxidizing agents of the effect produced by light was
then experimentally demonstrated, and photographs of the spectrum showed
that this effect was increased by the action of light itself. Thus, when
immersing a plate sensitive to all radiations, visible and invisible,
in a very dilute solution of nitric acid, bichromate of potash, or
hydroxyl, it was shown that if the plate were exposed to light, first
the parts acted upon by the red rays were reduced before the parts not
acted upon at all by the spectrum, thus conclusively proving that light
itself helped forward the oxidation or so-called solarization of the
image. It thus became a struggle, under ordinary circumstances, between
the reducing action on the normal salt and the oxidizing action on the
altered salt as to which should gain the mastery. If the reducing action
of any particular ray were the most active, then a negative image
resulted, whereas if the oxidizing action were in the ascendant, a
positive image resulted. Thus, in determining the action of light on
a particular salt, this antagonism had to be taken into account, and
exposure made with such precautions that no oxidizing action could
occur, as would be the case if an inorganic sensitizer, such as sulphite
of soda, were used.
The reversal of the image by soluble haloid salts, such as bromide of
potassium, was then dwelt upon with experimental demonstration. It was
shown that the merest trace of soluble haloid would reverse an image
by the extraction of bromine from it, and the fact that the most
refrangible part of the spectrum was principally efficacious in
completing this action showed how necessary it was to avoid falling
into error when analyzing photographic action by the spectroscope. A
reference was next made to gelatine plates, in which, owing to their
preparation, reversal through the above cause was most likely to take
place, and a plate soaked in sulphite of soda and exposed in the camera
for a couple of minutes--a time largely in excess of that necessary to
give a reversal under ordinary circumstances--proved the efficacy of
the oxygen absorber, the image remaining in its normal condition after
development.
The lecturer closed his remarks by showing the different molecular
states of iodide, bromide, and chloride of silver, as produced by
different modes of preparation. The color of the film by transmitted
light in every case indicated the effect which was likely to be produced
on them, and the photographed spectrum in each of them showed the
remarkable differences that were found. The points raised by Captain
Abney at different times are well worthy the study of scientific
photographers, since strict attention to the modes of exposure to the
spectrum, to the instruments employed, and to the source of light used
can alone insure accuracy in comparative experiments.--_Br. Jour. of
Photo_.
* * * * *
SALT AND LIME.
M.F.K. communicates the following interesting circumstance to _Neueste
Erfindung_.: A few years ago it was decided to whitewash the walls
and ceiling of a small cellar to make it lighter. For this purpose a
suitable quantity of lime was slaked. A workman who had to carry a
vessel of common salt for some other purpose stumbled over the lime
cask and spilled some of his salt into it. To conceal all traces of his
mishap he stirred in the salt as quickly as possible. The circumstance
came to my knowledge afterward, and this unintentional addition of salt
to the lime excited my liveliest curiosity, for the whitewash was not
only blameless, but hard as cement, and would not wash off.
After this experience I employed a mixture of milk of lime and salt
(about three parts of stone lime to one part of salt), for a court or
light well. To save the trouble and expense of a scaffold to work on, I
had it applied with a hand fire engine (garden syringe?) to the opposite
walls. The results were most satisfactory. For four years the weather
has had no effect upon it, and I have obtained a good and cheap means of
lighting the court in this way.
* * * * *
RENEWING PAINT WITHOUT BURNING.
It is stated in the _Gewerbeblatte fur Hessen_ that paint can be renewed
and refreshed in the following manner:
When cracks and checks appear in the paint on wooden articles, this
usually indicates that the varnish has cracked. If this is the case, the
article can easily be prepared for a fresh coat by sponging it over with
strong ammonia water, and two or three minutes later scraping off the
varnish with the broad end of a spatula before the ammonia has dried up.
In this way the first coat is removed. If it is necessary to remove the
next coating, the same operation is repeated. After the last coat
has been scraped off that is to be removed, it must be washed with
sufficient water to render the ammonia inactive, and then the surface is
rubbed with pulverized pumice to make it smooth. Any desired paint or
varnish can be applied to a surface prepared in this way.
* * * * *
TESTING OLIVE OIL.
By DR. O. BACH.
There is no department in analytical chemistry in which so little
success has been attained as in the testing of commercial fats and oils.
All methods that have been proposed for distinguishing and recognizing
the separate oils, alone or mixed, bear upon them the stamp of
uncertainty.
The facts observed by J. Koenig, and described by him in his excellent
book entitled "_Die Menschlichen Nahrungs und Genussmittel_" (p. 248),
excited great expectations; viz., that the quantity of glycerine in
vegetable fats was much less than the amount required to combine with
all the fatty acids, and that the quantity of oleic acid in the oils
that he examined exhibited essential differences. Koenig himself asserts
that the fats have hitherto been too little investigated to found upon
it a method for distinguishing them, but that nevertheless it may
possibly do good service in some cases.
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