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SCIENTIFIC AMERICAN SUPPLEMENT NO. 443.




NEW YORK, JUNE 28, 1884.

Scientific American Supplement. Vol. XVII., No. 443.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.

* * * * *




TABLE OF CONTENTS.


I. CHEMISTRY AND METALLURGY. - Beeswax and its Adulterations.
- Chemical ingredients. - Detection of adulterations. 7064

Phenol in the Stem, Leaves, and Cones of Pinus Sylvestris.
- A discovery bearing on the flora of the Carboniferous
epoch and the formation of petroleum. 7065

The School of Physics and Chemistry of Paris. - With
engraving of laboratory. 7065

Some Relations of Heat to Voltaic and Thermo Electric
Action of Metals in Electrolysis. - By G. GORE. 7070

II. ENGINEERING, MECHANICS, ETC. - Air Refrigerating
Machine. - 5 figures. 7071

A Gas Radiator and Heater. 7071

Concrete Water Pipes. 7071

The Sellers Standard System of Screw Threads. Nuts, and
Bolt Heads. - A table. 7072

An English Railway Ferry Boat. - 3 figures. 7072

The Problem of Flight and the Flying Machine. 7072

III. TECHNICAL. - Concrete Buildings for Farms. - How to construct
them. 7063

What Causes Paint to Blister and Peel? - How to prevent it. 7063

Olive Oil. - Difficulties encountered in raising an olive
crop. - Process of making Oil. 7064

IV. ELECTRICITY. ETC. - Telephony and Telegraphy on the Same
Wires Simultaneously. - 4 figures. 7067

The Electric Marigraph. - An apparatus for measuring the
height of the tide. - With engravings and diagrams showing
the Siemens and Halske marigraph and the operation of the
same. 7068

Delune & Co.'s System of Laying Underground Cables. - 2
figures. 7069

Electricity Applied to Horseshoeing. - Quieting an unruly
animal. - 3 engravings. 7069

Esteve's Automatic Pile. - 1 figure. 7070

Woodward's Diffusion Motor. 7070

V. ASTRONOMY. - Lunar Heat. - Its reflected and obscure
heat. - Trifling influence of the moon upon wind and
weather. - By Prof. C.A. YOUNG. 7073

VI. NATURAL HISTORY. - The Long-haired Pointer "Mylord."
- With engraving. 7073

VII. HORTICULTURE, ETC. - Apple Tree Borers. - Protection
against the same. 7074

Keffel's Germinating Apparatus. - With engraving. 7074

Millet. - Its Cultivation. 7074

VIII. MISCELLANEOUS. - Puerta del Sol, Madrid, Spain. - With
engraving. 7063

Dust-free Spaces. - A lecture delivered by Dr. OLIVER J.
LODGE before the Royal Dublin Society. 7067

* * * * *




PUERTA DEL SOL, MADRID.


Puerta del Sol, or Gate of the Sun, Madrid, is the most famous and
favorite public square in the Spanish city of Madrid. It was the
eastern portal of the old city. From this square radiate several of
the finest streets, such as Alcala, one of the handsomest
thoroughfares in the world, Mayor, Martera, Carretas, Geronimo. In our
engraving the post office is seen on the right. Large and splendid
buildings adorn the other sides, which embrace hotels, cafes, reading
rooms, elegant stores, etc. From this square the street railway lines
traverse the city in all directions. The population of the city is
about 400,000. It contains many magnificent buildings. Our engraving
is from _Illustrirte Zeitung_.

[Illustration: THE PUERTA DEL SOL, MADRID, SPAIN (From a Photograph.)]

* * * * *




CONCRETE BUILDINGS FOR FARMS.


Buildings made of concrete have never received the attention in this
country that they deserve. They have the merit of being durable and
fire-proof, and of not being liable to be blown down by violent winds.
It is very easy to erect them in places where sand and gravel are near
at hand and lime is comparatively cheap. Experiments made in England
show that coal screenings may be employed to good advantage in the
place of sand and gravel. Mr. Samuel Preston, of Mount Carroll, Ill.,
has a dwelling and several other buildings made of concrete and
erected by himself. They were put up in 1851, and are in excellent
condition. In _The Farmers' Review_ he gives the following directions
for building concrete walls:

First, secure a good stone foundation, the bottom below frost, the top
about one foot above ground. Near the top of the foundation bed in 2×4
scantling edgewise transversely with the walls, at such distances
apart as the length of the planks that form the boxes to hold the
concrete may require, the ends of the scantling to run six inches
beyond the outside and inside of the wall. Now take 2×6 studding, one
foot longer than the height of the concrete walls are to be, bolt in
an upright position in pairs to each end of the 2×4 scantling, and, if
a foot wall is to be built, sixteen inches apart, as the box plank
will take up four inches. To hold the studding together at the top,
take pieces of 2×6 lumber, make two mortises in each piece large
enough to slip easily up and down on the studding, forming a tie. Make
one mortise long enough to insert a key, so that the studding can be
opened at the top when the box plank are to be raised. When the box
plank are in position, nail cleats with a hole in each of them on each
side of the studding, and corresponding holes in the studding, into
which insert a pin to hold the plank to the studding. Bore holes along
up in the studding, to hold the boxes when raised.

To make the walls hollow, and I would do it in a building for any
purpose, use inch boards the same width of the box plank, one side
planed; put the two rough sides together with shingles between,
nailing them together with six-penny nails; place them in the middle
of the wall, the thin end of the shingle down. That gives them a bevel
and can be easily raised with the boxes. To tie the wall together, at
every third course place strips of boards a little shorter than the
thickness of the wall; cut notches in each so that the concrete will
fill in, holding all fast. The side walls being up, place two inch
planks on top of the wall upon which to rest the upper joists, put on
joist and rafters, remove the box plank, take inch boards for boxes,
cut to fit between joists and rafters, and fill with concrete to upper
side of rafters, which makes walls that will keep out cold and damp,
all kinds of vermin, and a roof which nothing but a cyclone can
remove. In making door and window frames, make the jambs two inches
narrower than the thickness of the walls, nailing on temporary two
inch strips.

Make the mortar bed large enough to hold the material for one course;
put in unslaked quicklime in proportion to 1 to 20 or 30 of other
material; throw into it plenty of water, and don't have that
antediluvian idea that you can drown it; put in clean sand and gravel,
broken stone, making it thin enough, so that when it is put into boxes
the thinner portion will run in, filling all interstices, forming a
solid mass. A brick trowel is necessary to work it down alongside the
boxing plank. One of the best and easiest things to carry the concrete
to the boxes is a railroad wheelbarrow, scooping it in with a scoop
shovel. Two courses a week is about as fast as it will be safe to lay
up the walls.

* * * * *

The _Medical Summary_ recommends the external use of buttermilk to
ladies who are exposed to tan or freckles.

* * * * *




WHAT CAUSES PAINT TO BLISTER AND PEEL?

HOW TO PREVENT IT.


This subject has been treated by many, but out of the numerous ideas
that have been brought to bear upon it, the writers have failed to
elucidate the question fully, probably owing to the fact that in most
parts they were themselves dubious as to the real cause. Last year
W.S. gave a lengthy description in the _Building News_, in which he
classified blistering and peeling of paint into one of blistering
only. He stated in the beginning of his treatise the following:

"The subject of blistering of paint has from time to time engrossed
the attention of practical men; but so far as we can follow it in the
literature pertaining to the building trade, its cause has never been
clearly laid down, and hence it is a detail enshrouded in mystery."

W.S. dwells mostly, in his following explanations on blistering
paints, on steam raised in damp wood. Also an English painter,
according to the _Painters' Journal_, lately reiterates the same
theory, and gives sundry reasons how water will get into wood through
paint, but is oblivious that the channels which lead water into wood
are open to let it out again. He lays great stress on boiled oil
holding water in suspense to cause blistering, which is merely a
conjecture. Water boils at 212° F. and linseed oil at 600° F.,
consequently no water can possibly remain after boiling, and a drop of
water put into boiling oil would cause an explosion too dangerous to
be encountered.

It will be shown herewith that boiled oil, though in general use, is
unfit for durable painting, that it is the cause of most of the
troubles painters have to contend with, and that raw linseed oil
seasoned by age is the only source to bind pigments for durable
painting; but how to procure it is another trouble to overcome, as all
our American raw linseed oil has been heated by the manufacturers, to
qualify it for quick drying and an early market, thereby impairing its
quality. After linseed oil has been boiled, it becomes a poor varnish;
it remains soft and pliable when used in paint, giving way to air
pressure from the wood in hot weather, forming blisters. Turpentine
causes no blistering; it evaporates upon being exposed, and leaves the
paint in a porous condition for the gas in the wood to escape; but all
painters agree that blistering is caused by gas, and on investigation
we find two main sources from which gas is generated to blister
paint - one from the wood, the other from the ingredients of the paint.
The first named source of gas is started in hot weather by expansion
of air confined in painted wood, which presses against the paint and
raises blisters when the paint is too soft to resist. Tough,
well-cemented paint resists the pressure and keeps the air back. These
blisters mostly subside as soon as the air cools and returns to the
pores, but subsequently peel off.

W.S. and others assert that damp in painted wood turns into steam when
exposed to sun heat, forming blisters, which cannot be possible when
we know that water does not take a gaseous form (steam) at less than
212° F. They have very likely been deluded by the known way of
distilling water with the aid of sunshine without concentrating the
rays of the sun, based upon the solubility of water in air, viz.: Air
holds more water in solution (or suspension) in a warmer than in a
cooler degree of temperature; by means of a simple apparatus
sun-heated air is guided over sun-heated water, when the air saturated
with water is conducted into a cooler, to give up its water again. But
water has an influence toward hastening to blister paint; it holds the
unhardened woodsap in solution, forming a slight solvent of the oil,
thereby loosening the paint from the wood, favoring blistering and
peeling. There is a certain kind of blister which appears in certain
spots or places only, and nowhere else, puzzling many painters. The
explanation of this is the same as before - soft paint at these spots,
caused by accident or sluggish workmen having saturated the wood with
coal oil, wax, tar, grease, or any other paint-softening material
before the wood was painted, which reacts on the paint to give way to
air pressure, forming blisters.

The second cause of paint blistering from the ingredients of the paint
happens between any layer of paint or varnish on wood, iron, stone, or
any other substance. Its origin is the gaseous formation of volatile
oils during the heated season, of which the lighter coal oils play the
most conspicuous part; they being less valuable than all other
volatile oils, are used in low priced japan driers and varnishes.
These volatile oils take a gaseous form at different temperatures, lie
partly dormant until the thermometer hovers at 90° F. in the shade,
when they develop into gas, forming blisters in airtight paint, or
escape unnoticed in porous paint. This is the reason why coal-tar
paint is so liable to blister in hot weather; an elastic, soft
coal-tar covering holds part of its volatile oil confined until heated
to generate into gas; a few drops only of such oil is sufficient to
spoil the best painted work, and worse, when it has been applied in
priming, it settles into the pores of the wood, needing often from two
to three repetitions of scraping and repainting before the evil is
overcome. Now, inasmuch as soft drying paint is unfit to answer the
purpose, it is equally as bad when paint too hard or brittle has been
used, that does not expand and contract in harmony with the painted
article, causing the paint to crack and peel off, which is always the
case when either oil or varnish has been too sparingly and turpentine
too freely used. Intense cold favors the action, when all paints
become very brittle, a fact much to be seen on low-priced vehicles in
winter time. Damp in wood will also hasten it, as stated in
blistering, the woodsap undermining the paint.

To avoid peeling and blistering, the paint should be mixed with raw
linseed oil in such proportions that it neither becomes too brittle
nor too soft when dry. Priming paint with nearly all oil and hardly
any pigment is the foundation of many evils in painting; it leaves too
much free oil in the paint, forming a soft undercoat. For durable
painting, paint should be mixed with as much of a base pigment as it
can possibly be spread with a brush, giving a thin coat and forming a
chemical combination called soap. To avoid an excess of oil, the
following coats need turpentine to insure the same proportion of oil
and pigment. As proof of this, prime a piece of wood and a piece of
iron with the same paint; when the wood takes up part of the oil from
the paint and leaves the rest in proportion to harden well, where at
the same time the paint on iron remains soft. To be more lucid, it
need be explained, linseed oil boiled has lost its oleic acid and
glycerine ether, which form with the bases of pigments the insoluble
soap, as well as its albumen, which in boiling is thrown out. It
coagulates at 160° F. heat; each is needed to better withstand the
action of wind and weather, preventing the dust from attaching itself
to a painted surface, a channel for ammonia in damp weather to
dissolve and wash off the paint. In later years linseed oil has been
extracted from linseed meal by the aid of naphtha and percolation, the
product of a very clear, quick drying oil, but lacking in its binding
quality, no doubt caused by the naphtha dissolving the fatty matter
only, leaving the glycerine and albumen in the meal.

All pigments of paint group according to their affinity to raw linseed
oil into three classes. First, those that form chemical combinations,
called soap. This kind is the most durable, is used for priming
purposes, and consists of lead, zinc, and iron bases, of which red
lead takes up the most oil; next, white lead, the pure carbonate Dutch
process made, following with zinc white and iron carbonates, as iron
ore paint, Turkey umber, yellow ocher; also faintly the chromates of
lead - chrome-green and chrome-yellow, finishing with the poorest of
all, modern white lead, made by the wet or vinegar process. The second
class being neutrals have no chemical affinity to linseed oil; they
need a large quantity of drier to harden the paint, and include all
blacks, vermilion, Prussian, Paris, and Chinese blue, also terra di
Sienna, Vandyke brown, Paris green, verdigris, ultramarine, genuine
carmine, and madderlake. The last seven are, on account of their
transparency, better adapted for varnish mixtures - glazing. The third
class of pigments act destructively to linseed oil; they having an
acid base (mostly tin salt, hydrochloride of tin, and redwood dye),
form with the gelatinous matter of the oil a jelly that will neither
work well under the brush nor harden sufficiently, and can be used in
varnish for glazing only; they are not permanent in color, and among
the most troublesome are the lower grades of so-called carmines,
madderlakes, rose pinks, etc., which contain more or less acidous
dyes, forming a soft paint with linseed oil that once dry on a job can
be twisted or peeled off like the skin of a ripe peach. All these
combinations of paint have to be closely observed by the painter to
insure his success.

Twenty-five years ago a house needed to be painted outside but once in
from five to seven years; it looked well all the time, as no dust
settled in the paint to make it unsightly. Painters then used the
Dutch-process-made white-lead, a base and raw linseed oil, a fat acid,
which formed the insoluble soap. They also put turpentine in the
following coats, to keep up the proportions of oil and pigment. All
held out well against wind and weather. Now they use the
wet-process-made white lead, neutralized by vinegar, with oil
neutralized by boiling, from the first to the last coat, and - fail in
making their work permanent.

W.S., in the _Building News_, relates an unaccountable mysterious
blistering in a leaky house, where the rainwater came from above on a
painted wood wall, blistering the paint in streaks and filled at the
lower ends with water, which no doubt was caused by the water soaking
the wood at the upper ends where there was no paint, and following it
down through the fibers, pushed and peeled off the soft, inadhesive
paint. Green, sappy, and resinous wood is unfit for durable painting,
and to avoid blistering and peeling wood should be well seasoned and
primed with all raw linseed oil, some drier, to insure a moderately
slow drying, and as much of a base pigment as the painter can possibly
spread (much drier takes up too much oil acid, needed for the pigment
base to combine with), which insures a tough paint that never fails to
stand against blistering or peeling, as well as wind, weather, and
ammonia.

The coach, car, and house painter can materially improve his painting
where his needs lie by first oiling the wood with raw oil, then
smoothing the surface down with lump pumicestone, washing it with a
mixture of japan drier or, better yet, gold sizing and turpentine,
wiping dry, and following it up with a coat of white lead, oil, and
turpentine. The explanation is: the raw oil penetrates the wood and
raises the wood fibers on the surface to be rubbed down with
pumicestone, insuring the best surface for the following painting: to
harden the oil in the wood it receives a coat of japan drier, which
follows into the pores and there forms a tough, resinous matter,
resisting any air pressure that might arise from within, and at the
same time reacts on the first coat of lead as a drier. This mode
insures the smoothest and toughest foundation for the following
painting, and may be exposed to the hottest July sun without fear of
either blistering or peeling.

LOUIS MATERN.

Bloomington, Ill.

* * * * *




OLIVE OIL.


The following particulars with regard to the production of olive oil
in Tuscany have been furnished to Mr. Consul Inglis by one of the
principal exporters in Leghorn:

The olive oil produced in Tuscany from the first pressing of the fruit
is intended for consumption as an article of food. Hence, great
attention is paid both to the culture of the olive tree and the
process of making oil.

The olive crop is subject to many vicissitudes, and is an uncertain
one. It may be taken as a rule that a good crop does not occur more
frequently than once in three years. A prolonged drought in summer may
cause the greater part of the small fruit to fall off the trees. A
warm and wet autumn will subject the fruit to the ravages of a maggot
or worm, which eats its way into it. Fruit thus injured falls to the
ground prematurely, and the oil made from it is of very bad quality,
being nauseous in taste and somewhat thick and viscous. Frost
following immediately on a fall of snow or sleet, when the trees are
still wet, will irretrievably damage the fruit, causing it to shrivel
up and greatly diminishing the yield of oil, while the oil itself has
a dark color, and loses its delicate flavor.

The olive tree in Tuscany generally blossoms in April. By November the
fruit has attained its full size, though not full maturity, and the
olive harvest generally commences then. The fruit, generally speaking,
is gathered as it falls to the ground, either from ripeness or in
windy weather. In some districts, however, and when the crop is short,
the practice is to strip the fruit from the trees early in the season.
When there is a full crop the harvest lasts many months, and may not
be finished till the end of May, as the fruit does not all ripen
simultaneously.

Oil made early in the season has a deeper color, and is distinguished
by a fruity flavor, with a certain degree of pungency; while as the
season advances it becomes lighter in color, thinner in body, and
milder and sweeter in taste. Oil made toward the close of the harvest
in April or May from extremely ripe fruit is of a very pale straw
color, mild and sweet to the taste, though sometimes, if the fruit has
remained too long on the trees, it may be slightly rancid. Oil very
light in color is much prized in certain countries, notably France,
and hence, if it also possesses good quality, commands a higher price
in the Tuscan markets.

The fruit of the olive tree varies just as much in quality as does the
grape, according to the species of the tree itself, the nature of the
soil, exposure, and climate of the locality where it grows. Some
varieties of the olive tree largely grown, because thought to be
better suited to the special conditions of some districts, yield a
fruit which imparts a bitter taste to the oil made from it; such oil,
even when otherwise perfect, ranks as a second rate quality.

The highest quality of oil can only be obtained when the fruit is
perfectly and uniformly sound, well ripened, gathered as soon as it
has dropped from the trees, and crushed immediately with great
attention. Should the fruit remain any time on the ground,
particularly during wet weather, it deteriorates fast and gets an
earthy taste; while if allowed to remain an undue length of time in
the garners it heats, begins to decompose, and will yield only bad
oil.

The process of making oil is as follows: The fruit is crushed in a
stone mill, generally moved by water power; the pulp is then put into
bags made of fiber, and a certain number of these bags, piled one upon
another, are placed in a press, most frequently worked by hand; when
pressure is applied, the oil flows down into a channel by which it is
conveyed to a receptacle or tank.

When oil ceases to flow, tepid water is poured upon the bags to carry
off oil retained by the bags. The pulp is then removed from the bags,
ground again in the mill, then replaced in the bags, and pressed a
second time. The water used in the process of making oil must be quite
pure; the mill, press, bags, and vessels sweet and clean, as the least
taint would ruin the quality of the oil produced.

The oil which has collected in the tank or receptacle just mentioned
is removed day by day, and the water also drained off, as oil would


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Online LibraryVariousScientific American Supplement, No. 443, June 28, 1884 → online text (page 1 of 7)