The great difference existing between metallurgical operations of the
present day, and those of a former period, is owing chiefly to the
ameliorations produced by the application of the science of chemistry
to the _modus operandi_ of the various changes taking place during the
operations, from their commencement to their termination.
Copper and some other metals are now made to assume forms in the
chemist's laboratory, that formerly required great artistical skill
for their production--the chemist simply making use of such agents and
forces as are at his command, and over which he has, by close
analytical study, acquired perfect control. Our object, at present, is
only to advert to the chemical investigations more recently made on
the manufacture of iron, treating of those changes that occur in the
ore, coal and flux, that are thrown in at the mouth of the furnace,
and in the air thrown in from below. For most that will be said on
this subject, we are principally indebted to the recent interesting
researches of M. Ebelman.
The importance of a knowledge of the facts to be brought forward, in
this article, will be apparent to every one in any way acquainted with
the manufacture of iron. It will be seen that the time is not far
distant when the economy in the article of fuel will amount in value
to the present profit of many of the works. The consequences must be,
that many of those works that are abandoned will be resumed, and
others erected in localities formerly thought unfit.
It is well known that the blast furnace is the first into which the
ore is introduced, for the purpose of converting it into malleable
iron, and much, therefore, depends upon the state in which the pig
metal passes from this furnace, whether subsequent operations will
furnish an iron of the first quality or not.
In putting the blast furnace into operation, the first step is to heat
it for some time with coal only. After the furnace has arrived at a
proper temperature, ore, fuel and flux, are thrown in alternately, in
small quantities, so as to have the three ingredients properly mixed
in their descent. In from 25 to 48 hours from the time when the ore is
first thrown in, the entire capacity of the furnace, from the tuyer to
the mouth, is occupied with the ore, fuel and flux, in their various
stages of transformation.
In order to explain clearly, and in as short space as possible, what
these transformations are, and how they are brought about, we may
consider:--1. The changes that take place in the descending mass,
composed of ore, fuel and flux. 2. The changes that take place in the
ascending mass, composed of air and its hygrometric moisture, thrown
in at the tuyer. 3. The chemical action going on between the ascending
and descending masses. 4. The composition of the gases in various
parts of the furnace during its operation. 5. The causes that render
necessary the great heat of the blast furnace.
1. _Changes that take place in the descending mass, composed of ore,
coal and flux._--By coal is here meant charcoal; when any other
species of fuel is alluded to, it will be specified. In the upper half
of the fire-room the materials are subjected to a comparatively low
temperature, and they lose only the moisture, volatile matter,
hydrogen, and carbonic acid, that they may contain; this change taking
place principally in the lower part of the upper half of the
fire-room.
In the lower half of the fire-room, the ore is the only material that
undergoes a change, it being converted wholly or in part into iron or
magnetic oxide of iron--the coal is not altered, no consumption of it
taking place from the mouth down to the commencement of the boshes.
From the commencement of the boshes down to the tuyer, the reduction
of the ore is completed. Very little of the coal is consumed between
the boshes and in the upper part of the hearth; the principal
consumption of it taking place in the immediate neighborhood of the
tuyer.
The fusion of the iron and slag occurs at a short distance above the
tuyer, and it is in the hearth of the furnace that the iron combines
with a portion of coal to form the fusible carburet or pig-iron. It is
also on the hearth that the flux combines with the siliceous and other
impurities of the ore. This concludes the changes which the ore, coal
and flux, undergo, from the mouth of the furnace to the tuyer.
If the fuel used be wood, or partly wood, it is during its passage
through the upper half of the fire-room that its volatile parts are
lost, and it becomes converted into charcoal. M. Ebelman ascertained
that wood, at the depth of ten feet, in a fire-room twenty-six feet
high, preserved its appearance after an exposure for 1 3-4 of an hour,
and that the mineral mixed with it preserved its moisture at this
depth; but three and a half feet lower, an exposure of 3 1-4 hours
reduced the wood to perfect charcoal, and the ore to magnetic oxide.
The temperature of the upper half of the fire-room, when wood is used,
is lower than in the case of charcoal, from the great amount of heat
made latent by the vapor arising from the wood. In the case of
bituminous coal, Bunsen and Playfair find that it has to descend still
lower before it is perfectly coked.
After the wood is completely charred, or the coal become coked, the
subsequent changes are the same that happen in the charcoal furnaces.
_To be continued._
=ANIMALCULAE IN WATER.=
[Illustration:]
The fact is generally known that nearly all liquids contain a variety
of minute living animals, though in some they are too small for
observation, even with a microscope. In others, especially in water
that has been long stagnant, these animals appear not only in hideous
forms, but with malignant and voracious propensities. The print at the
head of this article purports to be a microscopic representation of a
single drop of such water, with the various animals therein, and some
of the inventors and venders of the various improved filters for the
Croton water, would have no objection to the prevalence of the opinion
that this water contains all the variety of monsters represented in
this cut. But the fact is far otherwise; and it is doubtful whether
these animals could frequently be detected in the Croton water, with
the best solar microscope. Nevertheless, the fact is readily and
clearly established that the Croton water contains a quantity of
deleterious matter, which is arrested by the filters; and, on this
account, we cheerfully and heartily recommend the adoption of filters
by all who use this water, from either the public or private hydrants.
To this end we would call the special attention of our city readers to
the improved filters noticed under the head of "New Inventions."
=Length of Days.=
At Berlin and London the longest day has sixteen and a half hours. At
Stockholm and Upsal, the longest has eighteen and a half hours, and
the shortest five and a half. At Hamburg, Dantzic, and Stettin, the
longest day has seventeen hours, and the shortest seven. At St.
Petersburg and Tobolsk, the longest has nineteen, and the shortest
five hours. At Toreno, in Finland, the longest day has twenty-one
hours and a half, and the shortest two and a half. At Wandorbus, in
Norway, the day lasts from the 21st of May to the 22d of July, without
interruption; and in Spitzbergen, the longest day lasts three months
and a half.
=Excitement of Curiosity.=
The editor of the Cincinnati Enquirer, having been one of a recent
excursion party on the opening of a new section of railroad, remarks
on the occasion, 'It is really amusing to see the sensation a train of
railroad cars produces on all animate beings, human and brute, for the
first few times it passes over a section of road. We saw herds of
cattle, sheep, and horses, stand for a few seconds and gaze at the
passing train, then turn and run for a few rods with all possible
speed, stop and look again with eyes distended, and head and ears
erect, seemingly so frightened at the tramp of the iron horse as to
have lost the power of locomotion. Men women and children also seemed
dumbfounded at the strange and unusual spectacle. As the cars came
rumbling along early in the morning, they seemed to bring everybody
out of bed, all eager to catch a glance as we whirled past. Old men
and women, middle-aged and youth, without waiting to put on a rag in
addition to their night gear, were seen at the doors, windows and
round the corners of log huts and dwellings, gaping with wonder and
astonishment at the new, and to them grand and terrific sight.'
[COMMUNICATED.]
At the last special meeting of the National Association of Inventors,
called to hear the report on the rights and duties of the Editors of
the Eureka, on a resolution offered by one of the Editorial Committee
who had been dissatisfied by the proceedings of the 'Acting Editors,'
and refused to attend their sittings, it was reported that the 'Acting
Editors,' had exceeded their authority, and a majority of the
Editorial Committee resigned and a resolution was passed that the
resignation should be published in the Eureka, but it has not
appeared. Mr. Kingsley, one of the 'Acting Editors,' spoke at the said
meeting of having consulted counsel who had declared that the
Association were under a legal obligation to furnish Messrs. Kingley &
Pirsson with matter for publication in the Eureka, and on the
understanding that they had advanced money they were allowed to have
the first use of the reports and advertisements of the Association.
But as they in effect refuse to publish a resolution of great
importance to the reputation of all the parties interested, it is
left for the public to decide whether the 'Acting Editors' are in any
respect entitled to the name they have assumed for their paper.