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Scientific American Supplement, No. 841, February 13, 1892 online

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FIRING.

The letters are now taken and placed carefully on thin iron disks or
plates on the bench, where they remain until they are fired. It will
be remembered that we said at the outset that the factory was divided
into two large compartments, and it is into the second of these that
we now go.

Here are ranged the series of furnaces which convert the copper and
superincumbent enamel into one common body - fuse the one into the
other. An unwary step soon warns us that we are too near the furnace,
unless we want to run the risk of a premature cremation, and in the
interests of the readers of this journal we step back to a respectful
and proper distance, and watch the operations from afar.

There seems to be something innately picturesque about all furnaces
and those who work about them. Whether it is the Rembrandt effects
produced by the strong light and shade, or whether it is that the
necessary use of the long iron instruments, such as all furnace
workers employ, compels a certain dignity and grace of poise and
action, we know not; but certain it is that the grace is there in a
marked degree, and as we watched the men take their long-handled iron
tongs and place in or lift out the plates of hot metal, we could not
fail to be impressed with the charm of the physical action they
displayed.

The disk containing the enameled letters is taken at the end of a long
iron handle and carefully placed in a dome-shaped muffle. These
muffles are all heated from the outside; that is, the fire is all
round the chamber, but not in it, the fumes of the sulphur being
destructive of the enamel if they are allowed to come into contact
with it. So intense is the heat, however, that a muffle lasts only
about nine days, and at the end of that time has to be renewed.

[Illustration: FIRING THE LETTERS]

After the enamel is fused on to the copper, the disk is taken out and
placed on a side slab, where it is allowed to cool.

This process is repeated on the front side of the letter, when all
that remains to complete it is


THE FILING.

[Illustration: FILING THE LETTERS AFTER ENAMELING.]

This is done by girls, who, with very fine files, rub off the edges
and any protuberances which may be there. Every letter is subject to
this operation, and all are turned out smooth and well finished.

Sometimes the letters are colored or further defined by the addition
of a line, but the essentials are as we have already described.

[Illustration: MIXING THE ENAMEL]


BRUSHING OUT.

There are, however, one or two other operations of interest which we
may notice. The company do not confine their exertions to the making
of letters, various collateral developments having taken place which
fill an important part in this scheme of work.

Of these, small tablets, containing advertisements or notices, such as
we see in railway carriages, "Push after raising window," or "Close
this door after you," or some legend pertaining to Brown's Soap or
Robinson's Washing Powder. These are done by different processes, the
transfer process, as used in the potteries, being employed, but the
one most largely used is that of "brushing out," which is done by
plates.

Let us suppose that the tablet shows white letters on a dark ground,
the _modus operandi_ is as follows:

The tablet has been enameled, as already described, and is white. The
operator now takes a dark enamel and spreads it evenly over the entire
surface of the tablet. He, or she, now takes a stencil plate, of
tinfoil, out of which the ground is cut, leaving the letter in the
center.

This is carefully placed over the tablet and held tight with the left
hand, while with the right hand he holds a fine brush, which he uses
with a quick, sharp movement over the surface. This action readily
removes the unfired color from the hard, glassy surface underneath,
and leaves a white letter. This is fired, and is then complete.

Sometimes two and, it may be, three plates are necessary to complete
the brushing out, as ties must be left, as in the case of ordinary
stencils, and these have to be brushed out with additional plates. Two
or three colors may be introduced by this process, but each separate
color means separate firing. If the letters are dark on a light
ground, the process is exactly the same, the stencil only being
modified. In addition to the letters and tablets thus described, the
company also undertake the production of large enameled signs, and to
cope with the rapid expansion of this department of their work they
are erecting special furnaces, to enable them to deal with any demand
likely to be made upon them. The call for things permanent and
washable in the way of advertising is on the increase, and the
enameled plates made by the company is one of the most successful ways
of meeting the demand.

[Illustration: "THE SMITH A MIGHTY MAN IS HE."]

* * * * *




BURNING BRICK WITH CRUDE OIL FUEL.


At the present time there is not the least reason why either wood,
coal, or any other solid fuel should be used for the burning of brick.
This style of burning brick belongs to a past age. The art of
brickmaking has made tremendous progress during the past quarter of a
century. It is no longer the art of the ignorant; brains, capital,
experience, science, wide and general knowledge, must in these days be
the property of the successful brick manufacturer. There are some such
progressive brick manufacturers in Chicago, who use neither coal nor
wood in the drying or burning of their clay products. Crude oil is the
fuel which they employ, and with this fuel they obtain cheaper and
better brick than do manufacturers who employ solid fuel. Some of
these manufacturers have expressed themselves as preferring to quit
the brick business rather than return to the use of wood or coal as
fuel in brick burning.

This shows plainly that progress in our art, when it does come, comes
to remain. It is true that crude oil for brick-burning purposes is not
everywhere obtainable. But there is a fuel which is even better than
crude oil, namely, fuel gas, and which can be produced and employed on
any brick yard at a saving of seventy-five per cent. over coal or
other solid fuel.

The Rose process for making fuel gas gives a water gas enriched by
petroleum. Roughly, about half the cost of this gas as made at
Bellefonte, Pa., was for oil. The gas cost 6.68c. per 1,000 cu. ft.,
with oil at 2┬╝c. a gallon. At double this price the gas would cost but
10c., and show that in practice, foot for foot, it equals natural gas.

Fuel gas means a larger investment of capital than does any of the
other modes of brick burning, and is, therefore, not within the reach
of the entire trade. The cost of appliances for burning brick with
crude oil is not very large, and as all grate bars, iron frames, and
doors can be dispensed with in the use of crude oil fuel, the cost of
an oil-burning equipment is but little in excess of an equipment of
grates, etc., for coal-burning kilns.

At works using small amounts of fuel, especially if cost of fuel bears
but a small proportion to total cost of the manufactured product, oil
will be in the future very largely used. It is clean, as compared with
coal, can be easily handled, and when carefully used in small
quantities, is safe. There are several methods of burning oil that are
well adapted to the use of brick manufacturers and other fuel
consumers.

The Pennsylvania Railroad made some very thorough experiments on the
use of petroleum in their locomotives, and while the results obtained
are reported to have been satisfactory, it was the opinion of those
having the experiments in charge that the demand for the Pennsylvania
Railroad alone, were it to change its locomotives from coal to oil,
would consume all the surplus and send up the price of oil to a figure
that would compel a return to coal.

It is true that production has enormously increased in the last three
years, and the promise for the near future is that a high rate will be
maintained. It is further true that the production of Russia has
increased enormously, and will probably be larger this year than ever
before. This Russian oil must go to markets and supply demands that
have been met by American oil, and this will still further increase
the amount of oil available for fuel purposes.

There is no doubt, therefore, that petroleum has a future for fuel
uses. Many brick manufacturers are ready to use it, notwithstanding
the possibility of an advance in its cost.

While there are some objections to the use of petroleum as a fuel,
growing chiefly out of the risk attending its storage and conveyance
to the point of consumption, it is undoubtedly true that the chief
objection is the fear that with the increased demand that would follow
any extended use for this purpose would come an increase in price that
would make its continued use too expensive.

Just four years ago, when the fuel oil industry was first projected,
it was cried down because, as its enemies claimed, there was not
enough oil fuel to be obtained in America to supply the New York City
factories alone, to say nothing of other territory, and because of the
high prices for oil that were sure to follow its substitution for coal
fuel. Since then the industry has experienced a magnificent success,
the sales exceeding 20,000,000 barrels a year, while the price is
lower than ever.

A curious impression seems to have gained ground to the effect that
the Standard Oil Company does not want to sell oil for fuel. It may be
stated authoritatively that the company is not only able but willing
to sell and deliver oil for fuel purposes in any quantity that may be
desired. It is now delivering oil for fuel purposes in fourteen States
of the Union. For its sales in Chicago and the West and Northwest, the
delivery is by tank cars from the terminus of the pipe line at South
Chicago, to which point it is pumped from Lima, O. The Chicago price
is 1-2/3c. per gallon, or 70c. per barrel of 42 gallons, f.o.b. cars
at Chicago.

A great many of the brick manufacturers here and throughout the
Northwest are beginning to use crude petroleum as a substitute for
soft coal. It is smokeless, for the fine spray of oil which comes from
the injector consists of such minute drops of the liquid and is so
thoroughly mixed with oxygen that when it burns the combustion is
complete, and only steam and carbonic acid gas go out of the top of
the kiln. Not a speck of soot comes from the kiln or the smokestack or
soils the whitewashed purity of the boiler room. Oil fuel is
absolutely clean. It is labor saving, too. No fireman has to keep
shoveling coal, there are no ashes to be dragged out from under the
furnace grates, and there are no clinkers to clog up the bars. One
man, by turning a valve, may regulate the heat of a kiln containing
one million brick.

Not only is it cleaner than coal and calls for less labor, but it is
actually cheaper as a fuel. A barrel and a half of crude oil is equal
for furnace fuel to a ton of the best Illinois bituminous coal, and at
70c. a barrel any one can easily calculate the advantages petroleum
has over its smoky rival. Theoretically, two barrels of oil equal in
heating power one ton of best Pittsburg coal.

An examination into the relative cost of the Pittsburg and Chicago
coal to the oil consumed shows that the price of oil at Pittsburg is
59c. per barrel of 42 gallons, and slack coal can be purchased at from
70c. to 80c. per ton, and the best quality of lump coal at from $1.10
to $1.25 per ton, while the same quality of fuel can be bought in
Chicago at about 70c. a barrel, as against coal at from $2 to $3.50
per ton. It would, therefore, look as though there could be no
question whatever as to the economy and advantages to be derived from
the use of oil as a fuel in this vicinity.

The weight of oil required is less than half that of average coal to
produce the same amount of steam.

A great advantage in using oil as fuel in brick burning is that the
fires are always under the absolute and direct control of the man in
charge of the burning, who can regulate the volume of flame to the
nicest degree and throw the heat to any part of the arches that he may
desire.

From present indications, oil will be the fuel adopted generally for
generating power and for brick burning in Chicago, as it saves the
boilers, avoids grate bars, saves dirt and cinders, and reduces
running expenses, etc.

Much skepticism was at first exhibited in Chicago only a few years ago
when one of the leading brick manufacturers attempted to burn a kiln
of brick with coal for fuel. Nearly all the brickmakers then in
business put on wise looks and predicted the failure of the experiment
with coal. But coal proved to be a better and cheaper fuel than wood,
and in five or six years wood was used only for the kindling of the
coal fires.

Then came the attempt to burn brick with crude oil, and the experiment
having proved a success, coal has been banished from the leading brick
yards in Chicago and vicinity.

The Purington-Kimball Brick Co., Adams J. Weckler, Weber & La Bond,
the May-Purington Brick Co., the Union Brick Co., and the Pullman
Brick Co., all having headquarters in Chicago, as well as the Peerless
Brick Co. and the Pioneer Fireproof Construction Co., both of Ottawa,
Ill., are using crude oil fuel for brick burning.

Lima crude oil is used, and it is atomized by means of steam in small
furnaces extending about two feet from the face of the brick kilns,
and in which furnaces combustion occurs, and the conversion of the oil
and steam into a gaseous fuel is secured. There is little doubt that
the fuel employed in the future by the successful brick manufacturer
must be in the gaseous form. Owing to the enormous cost of handling
coal, wood, and other crude fuel, and of removing the ash resulting
from such fuel, it has been demonstrated in practice by the use of
crude oil that the expense connected with the burning of brick can be
reduced fully 60 per cent. This large saving is made by converting
crude petroleum into gas and utilizing this fuel, either directly in
the arches of the kiln or by converting the crude oil into gas in a
gas producer, and drawing this fuel gas from the producer and burning
the same as required in kilns of suitable construction.

Crude oil fuel must in the future play an important part in all
branches of manufacture requiring high, constant heats, and in which
the cost of wood, coal, and other solid fuels, together with the labor
cost of handling them, forms a considerable part of the cost of
production. Where coal is required to be hauled in carts from the
wharves, or from a line of railway to the brick yard, located a mile,
more or less, from the places where the coal is received, the cost of
handling, haulage, and waste is an important item. Added to these
costs, the deterioration of soft coal under atmospheric influences and
the waste from imperfect combustion and from the particles which fall
from the grate bars into the ash pits, all eat a large hole in the
brickmakers' profit.

Mr. D.V. Purington, of Chicago, Ill., in speaking on this subject,
says:

"I will say that my fuel bill for oil is cheaper than it would
cost me for coal. There is a very wide difference in the cost
of unloading, hauling away ashes and cinders, and getting my
coal around to the kiln, or boilers, or drier, or wherever I
use it, and I get very much better results by being able to
put the heat from oil fuel just where I want it."

In order to secure the best results with any fuel it is not only
necessary that a cheap fuel should be used, but that it should be
always obtainable, and that all of it should be burned and turned to
commercial account in the operations of brick manufacture.

Owing to the losses which we have previously mentioned, and resulting
from the use of coal, this fuel is destined to be superseded by some
form of fuel which will avoid such losses, and which will dispense
with all of the inconveniences now encountered in the handling of coal
and of the ashes resulting from combustion. Wood is rapidly becoming
too scarce and high near the great centers of man's habitation to be
regarded in the present discussion.

Fully two hundred million of brick a year are being burned in the city
of Chicago with crude oil fuel, and a clamp kiln containing one
million brick can be burned with crude oil in Chicago at a labor cost
of less than $100, and at a total cost for labor and oil of about 40c.
per thousand brick.

There are not, however, many places in the world where brick can be
burned with oil at such a low cost as in the city of Chicago; the
reason being that oil is not everywhere obtainable so cheaply as in
this city, and because few clays in the world are so easily burned
into brick as are the clays of Chicago. In Milwaukee, Wis., and in
other places within a distance of 100 miles from Chicago, the time
required to burn building brick with crude oil fuel averages from
sixteen to twenty-one days, whereas the time of burning the Chicago
clays averages only about five days, and splendid "burns" have been
secured there with crude oil in three and one-half days. It is
evident, therefore, that the advantages of using crude oil fuel for
the burning of brick will vary in different parts of the United
States.

Where circumstances and the nature of the clay permit of its use,
crude oil is, next to fuel gas, the brickmakers' ideal fuel. - _The
Brickmaker_.

* * * * *




INVESTIGATION OF A MOUND NEAR JEFFERSON CITY, MO.

By A.S. LOGAN.


Recently, a party consisting of engineers and employes of the Missouri
River Improvement Commission began an exploration of one of the
mounds, a work of a prehistoric race, situated on the bluff, which
overlooks the Missouri River from an elevation of one hundred and
fifty feet, located about six miles below Jefferson City.

This mound is one of about twenty embraced in a circle one quarter of
a mile in diameter.

The above party selected the mound in question apparently at
haphazard; all the mounds presenting nearly a uniform outline,
differing only in size and mostly circular in form, and from twenty to
twenty-four feet at the base, rising to a height of eight feet and
under. A trench was cut on a level with the natural soil, penetrating
the mound about eight feet. A stone wall was encountered which was
built very substantially, making access in that direction difficult,
in consequence of which the earth was removed from the top for the
purpose of entering from that direction. The earth was removed for a
depth of four feet, when the top of the wall was exposed. Further
excavation brought to light human bones, some of them fairly well
preserved, especially the bones of the legs. On the removal of these
and a layer of clay, another layer of bones was exposed, but
presenting a different appearance than the first, having evidently
been burned or charred, a considerable quantity of charcoal being
mixed with the bones. In this tier were found portions of several
skulls, lying close together, as if they had been interred without
regard to order. They were, in all probability, detached from the body
when buried.

The portions of the skulls found were those of the back of the head,
no frontal bones being discovered. Some jaw bones with the teeth
attached were among the remains, but only that portion of the jaw
containing the molar teeth.

A few pieces of flint weapons were found in the upper layers, and
nothing else of any significance.

At this juncture the diggers abandoned the search, and some days later
the writer, desirous of seeing all that was to be seen, resumed the
work and removed the earth and remains until the bottom of the vault
was reached; several layers being thus removed. All of these had
evidently been burned, as charcoal and ashes were mixed with the bones
of each succeeding layer. The layers were about an inch in thickness,
with from two to four inches of earth between, and small flat stones,
about the size of a man's hand, spread on each different layer, as if
to mark its division from the next above.

Between the bottom layers, mixed with charcoal, ashes and small
portions of burned bones were found what gives value to the search,
numbering about fifty tools and a smoking pipe.

The material of the tools is the same as the rock forming the vault,
locally known as "cotton rock." I would consider it a species of
sandstone.

Overlying the edge of "cotton rock" in the bluff is flint in great
quantities, and in every conceivable shape, that these people could
have resorted to had they been so disposed, and why they used the
softer material I will leave to some arch├Žologist to determine. The
tools themselves are made after no pattern, but selected for their
cutting qualities, as they all have a more or less keen edge which
could be used for cutting purposes, and were no doubt highly prized,
as they were found all in a pile in one corner of the vault and on top
of which was found a stone pipe. The pipe is made bowl and stem
together, and it is curious that people of such crude ideas of tools
and weapons should manufacture such a perfect specimen of a pipe. It
is composed of a very heavy stone, the nature of which would be
difficult to determine, as it is considerably burned.

A description of the vault will be found interesting to many. The wall
of the vault rests upon the natural surface of the ground, about three
feet high and eight and a half feet square, the inside corners being
slightly rounded; it is built in layers about four inches in thickness
and varying in length upward to three feet, neither cement nor mortar
being used in the joints; the corners formed a sort of recess as they
were drawn inward to the top, in which many of the stones were found.
The stone for constructing the vault was brought from a distance of
about a quarter of a mile, as there is none in sight nearer.

I assume from all these circumstances that these people lived in this
neighborhood anterior to the age of flint tools, as the more recent
interments indicate that they were then entering upon the flint
industry, and it may be that the "cotton rock" had become obsolete.

These people buried their dead on the highest ground, covering and
protecting them with these great mounds, when it would seem much
easier to bury as at the present day; but instead, they, with great
labor, carried the rock from a great distance, and it is reasonable to
suppose, also, that the earth was brought from a distance with which
they are surrounded, and piled high above, as there is no trace of an
immediate or local excavation.

In my view from the mounds and their surroundings I would
unhesitatingly say the water, the foot hills of the glacier and the
swamps left in its wake were but a short distance to the north of
them, and during the summer months the melting ice would send a volume
of water down this valley that the Missouri River of to-day is but a
miniature of, and therefore the highest hills were the only land that
could be used by that ancient race.

In this connection I would make the following suggestions that may
lead to more important disclosures: My object is the hope of a more
thorough investigation at some future time. Nearer to the top of the
mound was found, certainly, the remains of a people of more recent
date than those found in the vault, as their bones were larger, which
would indicate a more stalwart tribe, and also their mode of burial
was different, as there was no indication of fire being used, as was
the case with the lower burials. I would pronounce the upper
interments those of Indians of the present day; the tools found with
these were weapons of the chase. On the other hand, those found in the
vault were of a peaceful character, and their surroundings would
readily comport, in my opinion, to the glacial period. The entire
absence of flint in the bottom of the mound would show one of two
things, either they were unacquainted with the use of flint or at that
time there was no flint to be had. It is there now in great abundance,
in such forms for cutting purposes that would render the "cotton rock"
almost useless. The flint is found in a hill close to the river bank,
about half a mile from the mound, and the upper portion of the ledge
has the appearance, to me, of glacial action and probably forms a
moraine, as it has, evidently, been pushed over the underlying ledge,


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Online LibraryVariousScientific American Supplement, No. 841, February 13, 1892 → online text (page 9 of 11)