Various - Scientific American Supplement, No. 312, December 24, 1881
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Various >> Scientific American Supplement, No. 312, December 24, 1881
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It is not an easy matter to explain the classification of the ore at
Almaden. _Metal_ is there called the richest mineral, composed of
quartz impregnated with crystalline cinnabar. _Requiebro_ are
middlings of medium richness, _China_ are smalls, and _Vaciscos_ the
finest ore. Besides native mercury, which the ores of Almaden contain
in greater or smaller quantity, the most abundant mineral is cinnabar,
which is always crystalline and is often crystallized. The ores have,
besides, a small quantity of selenium and iron pyrites intimately
mixed with the cinnabar. The gangue is quartz, occasionally
argillaceous and bituminous. The following are assays of some of the
ores made by Escosura:
Metal. Requiebro. Vaciscos. China.
1 2 3 4 5 6 7 8
Cinnabar 29.1 21.2 13.3 10.2 5.1 2.8 1.2 0.86
Iron pyrites. 2.2 2.0 2.0 1.9 12.3 1.5 2.1 2.80
Bituminous matter 0.6 1.0 1.0 1.2 4.6 0.7 3.4 0.90
Gangue 67.5 74.8 82.1 76.5 77.5 93.3 90.2 93.50
---- ---- ---- ---- ---- ---- ---- -----
Total 99.4 94.0 98.8 98.9 99.5 98.3 98.7 98.06
Quicksilver 25.05 18.28 11.47 8.64 4.40 2.41 1.03 0.75
It appears to be a difficult matter to determine the average
percentage of the various grades of ore. In 1872, a commission
classified and sampled a lot of 300 tons with the following results:
Quantity, Per cent. Average of
Grade. No. kilos. mercury. grade.
Metal { 1. 81,890 23.86 }
{ 2. 14,970 22.65 } 24.80
Requiebro { 3. 12,240 15.20 }
{ 4. 17,000 10.50 } 12.47
China { 5. 31,890 3.84 }
{ 6. 32,360 1.17 } 1.75
{ 7. 28,960 0.10 }
Vaciscos 8. 78,320 9.24 9.24
This general average of 12.28 per cent. of mercury is pronounced
higher than the usual run of the ore, which, it is stated, does not go
above 7 to 8.50 per cent.
The furnace in which the ore is treated is cylindrical, 2 meters in
diameter, and 3.70 meters high from a brick grate, supported by three
arches to the arched roof. At the level of the grate is a charging
orifice, and near the roof are openings into two chambers, from the
bottom of which extend 12 lines of aludels, clay vessels, open at both
ends, the middle being expanded. The mouth of one fits into the back
end of the one following, a channel being thus formed through which
the fumes to be condensed are passed. The lines of aludels which are
laid on the ground terminate in a chamber, and for half the distance
between the furnaces and these chambers the ground slopes downward,
while for the other it slopes upward. Two furnaces are always placed
side by side, and the pair have from 1,100 to 1,150 aludels.
The operation is as follows: A layer of poor quartz is spread over the
brick grate; this is followed by a layer of smalls, and then by a
layer of still finer stuff, all of it being low grade ore. On top of
this are piled two-thirds of the _china_ of the charge on which the
_metal_ is put. Then follows a layer of _requiebro_, another lot of
_china_, and finally the _vaciscos_, shaped into balls, the whole
charge amounting to about 111/2 tons, which is put in from an hour and a
half to two hours by three men. The charging orifice is then closed,
the aludels are luted, and everything made tight. The fires under the
brick grate are lighted and kept going for twelve hours, during which
time furnaces, charge, and condensing apparatus are heated up. During
this period, the temperature in the condensing-chamber at the end of
the line of aludels runs up 40 or 50 degrees Celsius, and some
mercury, evidently part of the native quicksilver, is noticed in it.
The temperature of the aludels in the immediate vicinity of the
furnaces is about 140 degrees C. During this period, the consumption
of fuel is four parts to every part of quicksilver produced. At its
close, the fire is drawn, and the second period begins. The air
entering through the brick arch is heated to from 200 to 300 degrees
by contact with the layer of poor stuff, the cinnabar is ignited, and
its sulphur oxidized, and the quicksilver vaporized and, condensing in
the aludels, flows toward the depression in the central portion of the
line. The temperature goes on increasing, until, twelve hours after
the beginning of this period, the thermometer shows 212 degrees C. at
the first aludels. This lasts for 18 hours, and then the third or
"cooling period" begins, which takes from 24 to 26 hours, and during
the beginning of which the temperature in the furnaces still rises. It
is then opened and cooled down. A very elaborate series of
observations made on the temperatures of various parts of the
condensing apparatus of the Almaden furnaces has shown that at the
aludels nearest to them the heat increases steadily until it reaches
249 degrees C., 44 hours after the beginning of the operation; that in
the middle of the line, at the depression, the maximum is 50 degrees
50 hours after starting the fires; and that at the end it does not
surpass 39 degrees. In the final condensing chamber, the temperature
varied, running downward from 40 degrees during the heating period to
14 degrees, rising again to 29 degrees toward the close.
The loss of the quicksilver during the operation has been vary
variously estimated, some stating that it is 50 per cent. and more,
while others place it at 30 per cent. Escosura, in his work, gives the
details of an operation checked by a royal commission in 1872,
according to which the loss in working ore running 9.55 per cent. was
only 4.41 per cent.--a loss which he considered inevitable. In 1806,
two Idria furnaces were put up at Almaden, but the engineers are not
favorably impressed with them. The first cost is stated to be more
than ten times greater than that of an aludel furnace, while the
capacity is only 50 per cent. greater. One pair of Idria furnaces in
five years produced 120,000 kilogrammes of quicksilver, against
843,000 kilogrammes made by eight sets of the Bustamente furnaces, the
cost per kilogramme of quicksilver being respectively 0.121 and 0.056
peseta.
* * * * *
THE BALLOON IN AERONAUTICS.
While it is undoubtedly true that the discovery of the balloon has
very greatly retarded the science of aerostation, yet, in my opinion,
its field of usefulness as a vehicle for pleasure excursions, for
explorations, and for scientific investigations, has not been fully
developed for the want of certain improvements, the nature of which it
is the object of this paper to point out. The improvement of which I
am about to speak relates to the regulation of the buoyancy of the
balloon. This is now done by throwing out ballast or by allowing some
of the gas to escape--a method which necessitates the carrying of an
unwieldy amount of sand and the expenditure of an unnecessary amount
of gas.
From the fire balloon invented by the Montgolfier Brothers, in 1782,
to the superior hydrogen balloon of M.M. Charles and Robert, no
material advancement has been made, except the employment of coal gas,
first suggested by Mr. Green. The vast surface presented to the wind
makes the balloon unmanageable in every breeze, and the aeronaut can
do nothing but allow it to float along with the current. This is a
difficulty which has been partly overcome, as was seen at the recent
Paris Electrical Exhibition; but no one will ever be able to guide it
in a direction opposite to a current of air. The aeronaut must ever
content himself in being able to float in the direction of the current
or at certain angles to its course; but to do this even is a matter
which has not been successfully accomplished. An inflated balloon
would ascend too high unless several hundred pounds of ballast were
used to weight it down. This ballast serves another purpose, it is
desirable to maintain the balloon at a uniform distance above the
earth's surface, and as the two per cent. daily waste of gas
diminishes the buoyancy of the balloon, it must be kept from
descending by throwing off a certain amount of sand. Again, the heat
of the sun and the action of warm air currents cause at times the
volume of gas to undergo a sudden expansion, and then to prevent the
balloon from running too high, the gas must be allowed to escape from
the valve. The gas, under these circumstances, must also be allowed to
escape in order to prevent the balloon from bursting. Presently the
balloon will pass through a colder current of air and sudden
condensation takes place, and the balloon would sink unless more
ballast were thrown off. This process continues until the aeronaut has
neither ballast nor gas left.
Now, I suggest that a large balloon be made with the mouth closed, so
that no gas can escape; and that it carry enough ballast to keep it,
under an ordinary temperature, at a certain distance from the ground.
A pipe must enter the mouth of the balloon, one end of which opens in
its interior and the other end in a gas reservoir which lies in the
"basket" or "car." As soon as the gas undergoes an expansion, and a
certain amount of pressure is made in this reservoir, a valve opens
and a whistle signals the moment when the force pumps must be set to
work to pump the air out of the balloon into the large _number two_
reservoir, the frame work of which forms the body of the car. Taking a
certain amount of gas out of the balloon is equivalent to taking on
more ballast, while by condensing this gas into a large reservoir, it
is not allowed to escape, and when necessary can be sent back into the
balloon and thus prevent the throwing off of ballast. Coal gas, under
a certain pressure, becomes heavier than air (or at least equally
heavy), and thus the gas pumped out of the balloon will of itself
serve as ballast. This invention will enable the balloonist to keep
himself at a uniform distance above the earth, will prevent the
carrying of so much ballast and the expensive waste of gas, and will
enable him to keep afloat at least ten times as long as by the old
method. I have made a model and tested the above theory.
ELI C. OHMART.
North Manchester, Ind.
* * * * *
ARTISTS' HOMES. NO. 12--MR. WILLIAM EMERSON'S HOUSE AT LITTLE
SUTTON, CHISWICK.
[Illustration]
Little Sutton was an old house, parts of which were in existence
before the time of Cromwell. It is situated in a picturesque old
garden, surrounded by ivy-clad walls and fine trees, one of the cedars
being extraordinarily large and perfect, its huge branches covering a
space of over 90 ft. in diameter. The greater part of the old house,
being uninhabitable through decay, was pulled down; the old parts are
shown in black on the plan, and the new hatched. It is faced with red
bricks, and red Corsehill stone dressings, and covered with tiles The
plan was arranged so as to preserve the old kitchen, billiard-room,
morning room, and conservatory. The hall, entered from a veranda in
connection with the entrance-porch, is surrounded by a dado, the
height of doors; the lower panels are filled with tiles made to design
by the School of Art at Bombay. The woodwork is painted a mottled blue
color, harmonizing with the general tone of the tiles, the whole being
something the color of _lapis lazuli_. The staircase is divided from
the hall by three arches, through which is seen the staircase-window,
representing, in stained glass, the Earth, Air, and Water. Under the
central arch is the fireplace, on the hood of which will eventually be
a bronze figure of Orpheus, on a ground of mosaic. The floor is of
marble mosaic, and round the border are the various beasts listening
to the music, the trees and river, etc. Above the dado, and on the
wooden panels of ceiling, will be the birds, etc. The woodwork of
dining-room is plain American walnut, the panels of dado being filled
with dark Japanese leather-paper. The panels and beams of ceiling are
of stained and dull varnished fir. The drawing room woodwork, and
furniture throughout, is painted a mottled greenish blue, after the
same manner as the hall. The decorations of this room, when complete,
are intended to illustrate Chaucer's "House of Fame." The
chimney-piece, of alabaster, is surmounted by a Caen-stone design, on
a rock of glass, showing the entrance to the castle, with the various
figures mentioned in the poem, carved in half-round relief, and the
gateway itself also richly and quaintly carved; the rock of glass
representing the ice on which the castle was supposed to be built,
and on it are cut the various famous names of the world's history. In
the frieze all round the room will be the figure of Fame and the
various groups of suppliants, and the pillars with the groups
upholding the renown of ancient cities and nations, etc., executed in
very low relief, and painted on a ground of blue and gold. The panels
of ceilings will have conventional designs and the heavenly bodies on
ground of gold and blue. The morning and other rooms have no
particular scheme of decoration prepared, and are simply painted and
papered in quiet tones.
[Illustration: ARTISTS' HOMES No. 12--LITTLE SUTTON, CHISWICK.]
We publish a longitudinal section, taken through the hall and
drawing-room, with part of the dining-room on the left and part of the
library on the right-hand side. The beautifully-modeled plaster
frieze, with the central figure of Fame, is shown in the drawing-room,
and illustrates Chaucer's "House of Fame," the whole being elaborately
colored in harmony with the purposes and general tone of the room,
which is in blue and gold. The hooded mantelpiece in the library is
entirely in concrete, to be richly painted and gilded. The drawing,
with the assistance of the description, will explain
itself.--_Building News._
* * * * *
MEMORABLE ENGLISH HOUSES.
In the year 1864, a letter appeared in the _Journal of the Society of
Arts_ from a correspondent, who suggested that the Society of Arts
should offer a prize or prizes for designs of memorial tablets to be
affixed to houses associated with distinguished persons, and in the
same year a series of suggested inscriptions was reprinted from the
_Builder_. The subject having been brought under the notice of the
council, a committee was appointed in 1866 to consider and report how
the society might promote the erection of statues or other memorials
of persons eminent in arts, manufactures, and commerce, and, at the
first meeting of the committee, on May 7, Mr. George C.T. Bartley
submitted some memoranda on the proposal to place labels on houses in
the metropolis known to have been inhabited by celebrated persons In
1837, the first tablet was erected by the society in Holles Street,
Cavendish Square, on the house where Byron was born. Other tablets
were soon afterward put up, and the erection of these memorials has
been continued to the present time.
The house in Leicester Square, upon which a tablet in memory of
Hogarth has been erected, is occupied by Archbishop Tenison's school,
for which the house was rebuilt. The original building, in which
Hogarth lived for several years, was long known as the "Sabloniere
Hotel." John Hunter lived next door after Hogarth's death. Of the four
worthies who were intimately connected with Leicester Square, viz,
Hunter, Hogarth, Newton and Reynolds, and whose busts are now set up
at the four corners of the inclosure, the last three have tablets
erected.
The house in St. Martin's Street, which is now occupied by the schools
attached to the Orange Street Chapel, is in much the same condition as
when Sir Isaac Newton lived in it, from 1710 to 1727, except that the
old red bricks have been covered with stucco, and an observatory on
the roof has been taken away within the last few years.
[Illustration: NEWTON'S HOUSE, ST. MARTIN'S STREET.]
Flaxman had several London residences, but the house in Buckingham
Street, Fitzroy Square, is the one with which he is most intimately
associated, as he lived in it during the prime of his artistic career.
He went there in 1796, when he returned from Rome, and there he died
in 1826, being buried in the ground adjoining old St. Pancras Church
and belonging to the parish of St. Giles-in-the fields. The house is
on the south side of the street, close by Great Titchfield Street.
[Illustration: FLAXMAN'S HOUSE, BUCKINGHAM STREET.]
Canning's house, on the south side of Conduit Street is greatly
changed since the great statesman lived in it. It originally formed a
wing of Trinity Chapel, which has been swept away within the last few
years. This chapel was the successor of the chapel-on-wheels which was
used at the Hounslow camp in the reign of James II., and was
subsequently brought up to London. It is shown in Kip's view of old
Burlington House as standing in the fields at the back of that house.
When Conduit Street was built, a chapel was erected on the south side
to supersede the chapel-on-wheels. The house on the west side of the
chapel, where Canning lived for a time, was subsequently inhabited for
many years by the famous physician, Dr. Elliotson, F.R.S. After his
death, the front was altered, and a large shop window made, as seen
in the accompanying figure. It is now in the possession of Mr.
Streeter, the jeweler.
[Illustration: CANNING'S HOUSE.]
Dr. Johnson had so many residences in London that there is some
difficulty in choosing the one that is most interesting to us. The
house in Gough Square has special claims to attention, as it was there
that the great lexicographer chiefly compiled his dictionary. The
garret, with its slanting roof, in which his amanuenses worked, and
his own study are still to be been. Johnson himself, in his "Life of
Milton," observes, "I cannot but remark a kind of respect, perhaps
unconsciously, paid to this great man by his biographers; every house
in which he resided is historically mentioned, as if it were an injury
to neglect naming any place that he honored by his presence."
Emboldened by this expression of opinion, Boswell one evening, in the
year 1779, ventured to ask Johnson the names of some of his
residences, and he obtained the following list, which he printed in
his "Life of Johnson:" (1) Exeter Street, off Catherine Street,
Strand, (2) Greenwich; (3) Woodstock Street, near Hanover Square; (4)
Castle Street, Cavendish Square, No. 6, (5) Strand; (6) Boswell Court;
(7) Strand again; (8) Bow Street; (9) Holborn; (10) Fetter Lane; (11)
Holborn again, (12) Gough Square; (18) Staple's Inn; (14) Gray's Inn;
(15) Inner Temple Lane, No. 1; (16) Johnson's Court, No. 7; (17) Bolt
Court, No. 8. In this last place he died in 1784.
[Illustration: JOHNSON'S HOUSE.]
In April, 1879, the corporation of the city of London were asked to
co-operate in this work, and to undertake the erection of suitable
memorial tablets within the city boundaries. The matter was referred
to the city lands committee, with which body the secretary has had
several communications with respect to the localities suggested for
memorials, the result being that the committee agreed to erect such
tablets within the city boundaries.--_Journal of the Society of Arts._
* * * * *
DOMESTIC SUGAR PRODUCTION.
The value of sugar imported into the United States, is greater than
that of any other single article of commerce. In the year 1880 it
appears that over one thousand eight hundred and twenty-nine million
pounds of sugar were brought here from other countries, at a cost of
nearly one hundred and twenty million dollars, including customs duty.
Moreover, the consumption of sugar, _per capita_, in this country is
rapidly increasing. It was, during the ten years next preceding 1870,
only 28 pounds on the average per annum, but, in the ten years next
following, an average of 38 pounds per annum were consumed for each
person of the population of this country. This appears to be an
increase of 35 per centum in ten years.
The subject of domestic cultivation of sugar bearing plants is,
therefore, one of great importance to this nation, and it has
accordingly engaged the attention of the U.S. Commissioner of
Agriculture, and many experiments have been made in different parts of
the country in the propagation of the various canes, roots, etc., from
which sugar can be made. Among sugar-bearing plants, beside the
regular sugar cane, are, sorghum, sugar beet, maple, watermelon, sweet
and white potato, and corn stalk.
Statistics show that of the 12,000,000,000 pounds of sugar produced in
the world, about three-fourths comes from the sugar cane, and the
other fourth comes mainly from the sugar beet. Of the total quantity,
only about one seventieth is produced in the United States, and that
is mainly cane sugar from Louisiana. The beet sugar has formerly been
mainly produced in Europe. First France, second Germany, third Russia,
then Belgium, Austria, Holland, Sweden, and Italy.
The consumption of sugar in Great Britain is much greater _per capita_
than in the United States, about 65 pounds, or nearly double; while in
Germany 19 pounds per annum are used on an average by each person, and
in Russia the consumption is much less.
The importance of this subject to the United States, where the
consumption of sugar is increasing out of ratio to the production of
sugar-bearing plants, and where agricultural independence should be
realized, as we have already attained and maintained political
independence, and almost independence in manufacturing industries, has
called out Mr. Lewis S. Ware, a member of the American Chemical
Society, etc., in a pamphlet of over 60 pages, entitled a "_Study of
the Various Sources of Sugar_."
From this publication it appears that the main source of sugar supply
must still be _sucrose_, cane sugar, even in spite of the best efforts
of the general government and of the State agricultural organizations
to introduce sugar-bearing plants that will thrive in the temperate
and colder latitudes of this country. With the single exception of the
sugar beet, he seems to disparage all attempts to produce practical
sugar from hardy plants, or those that will mature in the region of
frosts in winter. Even sorghum, that has for twenty years held a place
in the hopes of the northern farmer, has declined so that the alleged
production of half a million pounds in 1866 had became barely a
twelfth of a million pounds in 1877.
In his remarks on the synopsis of one hundred and eleven experiments,
made at Washington, he says: "As may be noticed, thirty-five of them
(111) would yield zero. If we take the average of the hundred and
eleven experiments, we find as a yield 4.5 per cent., which result
cannot possibly be practically accepted. In other words, our
government, notwithstanding the favorable conditions under which they
were made, prove that the sorghum utilization is fallacy in every
sense of the word." ... "If sorghum is to be grown for its sirup, or
for fodder, it will evidently render excellent service." It seems that
less than four per cent. of crystallizable sugar in the sorghum juice
will not pay the cost of making sugar from it, as it will not
crystallize in a reasonable time, on account of the glucose in the
juice, which, with the other impurities, will prevent the ready
crystallization of four or five times their own weight of sucrose.
From the early history of sorghum, it appears that it was known as
_sorgo_ in the sixteenth century, while twenty or thirty varieties
were known under different names in Egypt, Arabia, and Africa. Some of
the names are, Chinese sugar cane, (sorgo), India cane, emphee or
Coffers' bread, paindes anges, etc.
The later history of it shows that in 1850, Count Montigny sent the
first samples from China to Europe. It had been used in the former
country for thousands of years for the manufacture of red dye. The
seeds were afterward sold in France for a _franc_ each.
A variety came later to this country from Africa, through the agency
of an Englishman named Wray, to whom is charged the effects of the
delusive experiments of trying to make crystallized sugar from its
juice, which have been going on in this country for twenty years. But
two varieties of sorghum now remain, known as the Chinese and African
types. Of all the other sugar plants, none except the maple tree
(besides the sugar cane and the beet) seem to have yielded sugar to
pay the cost of manufacture. The maple tree has yielded a total of
41,000,000 pounds in 1877. But as an industry by itself, it appears to
be unprofitable, and maple sugar must be, and generally is, sold at a
higher price per pound than cane sugar; moreover, it has not the
qualities that are required in a general sweetner for culinary
purposes.
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