Scientific American Supplement No. 360, November 25, 1882 by Various

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SCIENTIFIC AMERICAN SUPPLEMENT NO. 360

NEW YORK, NOVEMBER 25, 1882

Scientific American Supplement. Vol. XIV, No. 360.

Scientific American established 1845

Scientific American Supplement, $5 a year.

Scientific American and Supplement, $7 a year.

* * * * *

TABLE OF CONTENTS.

I. ENGINEERING AND MECHANICS.--Soaking Pits for Steel Ingots.
--On the successful rolling of steel ingots with their own
initial heat by means of the soaking pit process. By JOHN GJERS.
6 figures.--Gjers' soaking pits for steel ingots.

Tempering by compression.--L. Clemandot's process.

Economical Steam Power. By WILLIAM BARNET LE VAN.

Mississippi River Improvements near St. Louis, Mo.

Bunte's Burette for the Analysis of Furnace Gases. 2 figures.

The "Universal" Gas Engine. 8 figures.--Improved gas engine.

Gas Furnace for Baking Refractory Products. 1 figure.

The Efficiency of Fans. 5 figures.

Machine for Compressing Coal Refuse into Fuel. 1 figure.--
Bilan's machine.

Hank Sizing and Wringing Machine. 1 figure.

Improved Coke Breaker. 2 figures.

Improvements in Printing Machinery. 2 figures.

II. TECHNOLOGY AND CHEMISTRY.--Apparatus for Obtaining
Pure Water for Photographic Use. 3 figures.

Black Phosphorus.--By P THENARD.

Composition of Steep Water

Schreiber's Apparatus for Revivifying Bone Black. 5 figures.--
Plant: elevation and plan.--Views of elevation.--Continuous
furnace.

Soap and its Manufacture from a Consumer's Point of View.
(Continued from SUPPLEMENT, No. 330).

Cotton seed Oil.--By S. S. BRADFORD.

On some Apparatus that Permit of Entering Flames.--Chevalier
Aldini's wire gauze and asbestos protectors.--Brewster's account
of test experiments.

III. ELECTRICITY, LIGHT. ETC.--On a New Arc Electric Lamp.
By W. H. PREECE. 6 figures--The Abdank system.--The lamp.--
The Electro-magnet.--The Cut-off.--The electrical arrangement.

Utilization of Solar Heat.

IV. NATURAL HISTORY.--The Ocellated Pheasant. 1 figure.

The Maidenhair Tree in the Gardens at Broadlands, Hants,
England. 1 figure.

The Woods of America.--The Jessup collection in the American
Museum of Natural History, Central Park, and the characteristics
of the specimens.

V. AGRICULTURE, ETC.--An Industrial Revolution.--Increase in
the number of farms.

A Farmer's Lime Kiln. 3 figures.

The Manufacture of Apple Jelly.

Improved Grape Bags. 4 figures.

VI. ARCHITECTURE, ETC.--The Building Stone Supply.--Granite
and its sources.--Sandstone.--Blue and gray limestone.--Marble.--
Slate.--Other stones.--A valuable summary of the sources and uses
of quarry products.

VII. ASTRONOMY. ETC.--How to Establish a True Meridian. By
Prof. L. M. HAUPT.--Introduction.--Definitions.--To find the
azemuth of Polaris.--Applications, etc.

VIII. MISCELLANEOUS.--A Characteristic Mining "Rush."--The
Prospective Mining Center of Southern New Mexico.

The Food and Energy of Man. By Prof. DE CHAUMONT.--Original
food of man.--Function of food.--Classes of alimentary
substances.--Quantity of food.--Importance of varied diet.

Rattlesnake Poison.--Its Antidotes. By H. H. CROFT.

The Chinese Sign Manual.--The ethnic bearing of skin furrows
on the hand.

Lucidity.--Matthew Arnold's remarks at the reopening of the
Liverpool University College and School of Medicine.

* * * * *

SOAKING PITS FOR STEEL INGOTS.

ON THE SUCCESSFUL ROLLING OF STEEL INGOTS WITH THEIR OWN INITIAL HEAT BY
MEANS OF THE SOAKING PIT PROCESS.

By Mr. JOHN GJERS, Middlesbrough.

[Footnote: Paper read before the Iron and Steel Institute at Vienna.]

When Sir Henry Bessemer, in 1856, made public his great invention, and
announced to the world that he was able to produce malleable steel from
cast iron without the expenditure of any fuel except that which already
existed in the fluid metal imparted to it in the blast furnace, his
statement was received with doubt and surprise. If he at that time had
been able to add that it was also possible to roll such steel into a
finished bar with no further expenditure of fuel, then undoubtedly the
surprise would have been much greater.

Even this, however, has come to pass; and the author of this paper
is now pleased to be able to inform this meeting that it is not only
possible, but that it is extremely easy and practical, by the means to
be described, to roll a steel ingot into, say, a bloom, a rail, or other
finished article with its own initial heat, without the aid of the
hitherto universally adopted heating furnace.

It is well understood that in the fluid steel poured into the mould
there is a larger store of heat than is required for the purpose
of rolling or hammering. Not only is there the mere apparent high
temperature of fluid steel, but there is the store of latent heat in
this fluid metal which is given out when solidification takes place.

It has, no doubt, suggested itself to many that this heat of the ingot
ought to be utilized, and as a matter of fact, there have been, at
various times and in different places, attempts made to do so; but
hitherto all such attempts have proved failures, and a kind of settled
conviction has been established in the steel trade that the theory could
not possibly be carried out in practice.

The difficulty arose from the fact that a steel ingot when newly
stripped is far too hot in the interior for the purpose of rolling, and
if it be kept long enough for the interior to become in a fit state,
then the exterior gets far too cold to enable it to be rolled
successfully. It has been attempted to overcome this difficulty
by putting the hot ingots under shields or hoods, lined with
non-heat-conducting material, and to bury them in non-heat-conducting
material in a pulverized state, for the purpose of retaining and
equalizing the heat; but all these attempts have proved futile in
practice, and the fact remains, that the universal practice in steel
works at the present day all over the world is to employ a heating
furnace of some description requiring fuel.

The author introduced his new mode of treating ingots at the Darlington
Steel and Iron Company's Works, in Darlington, early in June this year,
and they are now blooming the whole of their make, about 125 tons a
shift, or about 300 ingots every twelve hours, by such means.

The machinery at Darlington is not adapted for rolling off in one heat;
nevertheless they have rolled off direct from the ingot treated in the
"soaking pits" a considerable number of double-head rails; and the
experience so gained proves conclusively that with proper machinery
there will be no difficulty in doing so regularly. The quality of the
rails so rolled off has been everything that could be desired; and as
many of the defects in rails originate in the heating furnace, the
author ventures to predict that even in this respect the new process
will stand the test.

Many eminently practical men have witnessed the operation at Darlington,
and they one and all have expressed their great surprise at the result,
and at the simple and original means by which it is accomplished.

The process is in course of adoption in several works, both in England
and abroad, and the author hopes that by the time this paper is being
read, there may be some who will from personal experience be able to
testify to the practicability and economy of the process, which is
carried out in the manner now to be described.

A number of upright pits (the number, say, of the ingots in a cast) are
built in a mass of brickwork sunk in the ground below the level of the
floor, such pits in cross-section being made slightly larger than that
of the ingot, just enough to allow for any fins at the bottom, and
somewhat deeper than the longest ingot likely to be used. In practice
the cross section of the pit is made about 3 in. larger than the large
end of the ingot, and the top of the ingot may be anything from 6 in. to
18 in. below the top of the pit. These pits are commanded by an ingot
crane, by preference so placed in relation to the blooming mill that the
crane also commands the live rollers of the mill.

Each pit is covered with a separate lid at the floor level, and after
having been well dried and brought to a red heat by the insertion of hot
ingots, they are ready for operation.

As soon as the ingots are stripped (and they should be stripped as early
as practicable), they are transferred one by one, and placed separately
by means of the crane into these previously heated pits (which the
author calls "soaking pits") and forthwith covered over with the lid,
which practically excludes the air. In these pits, thus covered, the
ingots are allowed to stand and soak; that is, the excessive molten
heat of the interior, and any additional heat rendered sensible during
complete solidification, but which was latent at the time of placing
the ingots into the pit, becomes uniformly distributed, or nearly so,
throughout the metallic mass. No, or comparatively little, heat being
able to escape, as the ingot is surrounded by brick walls as hot as
itself, it follows that the surface heat of the ingot is greatly
increased; and after the space of from twenty to thirty minutes,
according to circumstances, the ingot is lifted out of the pit
apparently much hotter than it went in, and is now swung round to the
rolls, by means of the crane, in a perfect state of heat for rolling,
with this additional advantage to the mill over an ingot heated in an
ordinary furnace from a comparatively cold, that it is always certain to
be at least as hot in the center as it is on the surface.

[Illustration: Fig. 2]

Every ingot, when cast, contains within itself a considerably larger
store of heat than is necessary for the rolling operation. Some of this
heat is, of course, lost by passing into the mould, some is lost by
radiation before the ingot enters into the soaking pit, and some is lost
after it enters, by being conducted away by the brickwork; but in the
ordinary course of working, when there is no undue loss of time in
transferring the ingots, after allowing for this loss, there remains a
surplus, which goes into the brickwork of the soaking pits, so that this
surplus of heat from successive ingots tends continually to keep the
pits at the intense heat of the ingot itself. Thus, occasionally it
happens that inadvertently an ingot is delayed so long on its way to the
pit as to arrive there somewhat short of heat, its temperature will be
raised by heat from the walls of the pit itself; the refractory mass
wherein the pit is formed, in fact, acting as an accumulator of heat,
giving and taking heat as required to carry on the operation in a
continuous and practical manner.

[Illustration: GJERS' SOAKING PITS FOR STEEL INGOTS.]

During the soaking operation a quantity of gas exudes from the ingot and
fills the pit, thus entirely excluding atmospheric air from entering;
this is seen escaping round the lid, and when the lid is removed
combustion takes place.

It will be seen by analyses given hereinafter that this gas is entirely
composed of hydrogen, nitrogen, and carbonic oxide, so that the ingots
soak in a perfectly non-oxidizing medium. Hence loss of steel by
oxidation does not take place, and consequently the great loss of
yield which always occurs in the ordinary heating furnace is entirely
obviated.

The author does not think it necessary to dilate upon the economical
advantages of his process, as they are apparent to every practical man
connected with the manufacture of steel.

The operation of steel making on a large scale will by this process be
very much simplified. It will help to dispense with a large number of
men, some of them highly paid, directly and indirectly connected with
the heating department; it will do away with costly heating furnaces and
gas generators, and their costly maintenance; it will save all the coal
used in heating; and what is perhaps of still more importance, it will
save the loss in yield of steel; and there will be no more steel spoiled
by overheating in the furnaces.

The process has been in operation too short a time to give precise
and reliable figures, but it is hoped that by the next meeting of the
Institute these will be forthcoming from various quarters.

Referring to the illustrations annexed, Fig. 1 shows sectional
elevation, and Fig. 2 plan of a set of eight soaking pits (marked
A). These pits are built in a mass of brickwork, B, on a concrete
foundation, C; the ingots, D, standing upright in the pits. The pits are
lined with firebrick lumps, 6 in. thick, forming an independent lining,
E, which at any time can be readily renewed. F is a cast iron plate,
made to take in four pits, and dropped loosely within the large plate,
G, which surrounds the pits. H is the cover, with a firebrick lining;
and I is a false cover of firebrick, 1 in. smaller than the cross
section of the pit, put in to rest on the top of the ingot. This false
cover need not necessarily be used, but is useful to keep the extreme
top of the ingot extra hot. J is the bottom of the pit, composed of
broken brick and silver sand, forming a good hard bottom at any desired
level.

Figs. 4 and 5 show outline plan of two sets of soaking pits, K K, eight
each, placed under a 25 ft. sweep crane, L. This crane, if a good one,
could handle any ordinary make--up to 2,000 tons per week, and ought to
have hydraulic racking out and swinging round gear. This crane places
the ingots into the pits, and, when they are ready, picks them out and
swings them round to blooming mill, M. With such a crane, four men and a
boy at the handles are able to pass the whole of that make through the
pits. The author recommends two sets of pits as shown, although one set
of eight pits is quite able to deal with any ordinary output from one
Bessemer pit.

In case of an extraordinarily large output, the author recommends a
second crane, F, for the purpose of placing the ingots in the pits
only, the crane, L, being entirely used for picking the ingots out
and swinging them round to the live rollers of the mill. The relative
position of the cranes, soaking pits, and blooming mill may of course be
variously arranged according to circumstances, and the soaking pits may
be arranged in single or more rows, or concentrically with the crane at
pleasure.

Figs. 4 and 5 also show outline plan and elevation of a Bessemer plant,
conveniently arranged for working on the soaking pit system. A A are
the converters, with a transfer crane, B. C is the casting pit with
its crane, D. E E are the two ingot cranes. F is a leading crane which
transfers the ingots from the ingot cranes to the soaking pits, K K,
commanded by the crane, L, which transfers the prepared ingots to the
mill, M. as before described.

* * * * *

TEMPERING BY COMPRESSION.

L. Clemandot has devised a new method of treating metals, especially
steel, which consists in heating to a cherry red, compressing strongly
and keeping up the pressure until the metal is completely cooled. The
results are so much like those of tempering that he calls his process
tempering by compression. The compressed metal becomes exceedingly hard,
acquiring a molecular contraction and a fineness of grain such that
polishing gives it the appearance of polished nickel. Compressed steel,
like tempered steel, acquires the coercitive force which enables it to
absorb magnetism. This property should be studied in connection with
its durability; experiments have already shown that there is no loss of
magnetism at the expiration of three months. This compression has no
analogue but tempering. Hammering and hardening modify the molecular
state of metals, especially when they are practiced upon metal that is
nearly cold, but the effect of hydraulic pressure is much greater.
The phenomena which are produced in both methods of tempering may be
interpreted in different ways, but it seems likely that there is a
molecular approximation, an amorphism from which results the homogeneity
that is due to the absence of crystallization. Being an operation which
can be measured, it may be graduated and kept within limits which are
prescribed in advance; directions may be given to temper at a
specified pressure, as readily as to work under a given pressure of
steam.--_Chron. Industr_.

* * * * *

ECONOMICAL STEAM POWER.

[Footnote: A paper read by title at a recent stated meeting of the
Franklin Institute]

By WILLIAM BARNET LE VAN.

The most economical application of steam power can be realized only by
a judicious arrangement of the plant: namely, the engines, boilers, and
their accessories for transmission.

This may appear a somewhat broad assertion; but it is nevertheless one
which is amply justified by facts open to the consideration of all those
who choose to seek for them.

While it is true that occasionally a factory, mill, or a water-works
may be found in which the whole arrangements have been planned by a
competent engineer, yet such is the exception and not the rule, and such
examples form but a very small percentage of the whole.

The fact is that but few users of steam power are aware of the numerous
items which compose the cost of economical steam power, while a yet
smaller number give sufficient consideration to the relations which
these items bear to each other, or the manner in which the economy of
any given boiler or engine is affected by the circumstances under which
it is run.

A large number of persons--and they are those who should know better,
too--take for granted that a boiler or engine which is good for one
situation is good for all; a greater error than such an assumption can
scarcely be imagined.

It is true that there are certain classes of engines and boilers which
may be relied upon to give moderately good results in almost any
situation--and the best results should _always_ be desired in
arrangement of a mill--there are a considerable number of details which
must be taken into consideration in making a choice of boilers and
engines.

Take the case of a mill in which it has been supposed that the motive
power could be best exerted by a single engine. The question now is
whether or not it would be best to divide the total power required among
a number of engines.

_First_.--A division of the motive power presents the following
advantages, namely, a saving of expense on lines of shafting of large
diameter.

_Second_.--Dispensing with the large driving belt or gearing, the first
named of which, in one instance under the writer's observation, absorbed
_sixty horse-power_ out of about 480, or about _seven per cent_.

_Third_.--The general convenience of subdividing the work to be done,
so that in case of a stoppage of one portion of the work by reason of
a loose coupling or the changing of a pulley, etc., that portion only
would need to be stopped.

This last is of itself a most important point, and demands careful
consideration.

For example, I was at a mill a short time ago when the governor belt
broke. The result was a stoppage of the whole mill. Had the motive power
of this mill been subdivided into a number of small engines only one
department would have been stopped. During the stoppage in this case
the windows of the mill were a sea of heads of men and women (the
operatives), and considerable excitement was caused by the violent
blowing off of steam from the safety-valves, due to the stoppage of the
steam supply to the engine; and this excitement continued until the
cause of the stoppage was understood. Had the power in this mill been
subdivided the stoppage of one of a number of engines would scarcely
have been noticed, and the blowing off of surplus steam would not have
occurred.

In building a mill the first item to be considered is the interest on
the first cost of the engine, boilers, etc. This item can be subdivided
with advantage into the amounts of interest on the respective costs of,

_First_. The engine or engines;

_Second_ The boiler or boilers;

_Third_. The engine and boiler house.

In the same connection the _form_ of engine to be used must be
considered. In some few cases--as, for instance, where engines have to
be placed in confined situations--the form is practically fixed by the
space available, it being perhaps possible only to erect a vertical or a
horizontal engine, as the case may be. These, however, are exceptional
instances, and in most cases--at all events where large powers are
required--the engineer may have a free choice in the matter. Under
these circumstances the best form, in the vast majority of cases where
machinery must be driven, is undoubtedly the horizontal engine, and the
worst the beam engine. When properly constructed, the horizontal engine
is more durable than the beam engine, while, its first cost being less,
it can be driven at a higher speed, and it involves a much smaller
outlay for engine house and foundations than the latter. In many
respects the horizontal engine is undoubtedly closely approached in
advantages by the best forms of vertical engines; but on the whole we
consider that where machinery is to be driven the balance of advantages
is decidedly in favor of the former class, and particularly so in the
case of large powers.

The next point to be decided is, whether a condensing or non-condensing
engine should be employed. In settling this question not only the
respective first costs of the two classes of engines must be taken into
consideration, but also the cost of water and fuel. Excepting, perhaps,
in cases of very small powers, and in those instances where the exhaust
steam from a non-condensing engine can be turned to good account for
heating or drying purpose, it may safely be asserted that in all
instances where a sufficient supply of condensing water is available
at a moderate cost, the extra economy of a well-constructed condensing
engine will fully warrant the additional outlay involved in its
purchase. In these days of high steam pressures, a well constructed
non-condensing engine can, no doubt, be made to approximate closely to
the economy of a condensing engine, but in such a case the extra cost of
the stronger boiler required will go far to balance the additional cost
of the condensing engine.

Having decided on the form, the next question is, what "class" of engine
shall it be; and by the term class I mean the relative excellence of the
engine as a power-producing machine. An automatic engine costs more than
a plain slide-valve engine, but it will depend upon the cost of fuel at
the location where the engine is to be placed, and the number of hours
per day it is kept running, to decide which class of machine can be
adopted with the greatest economy to the proprietor. The cost of
lubricating materials, fuel, repairs, and percentage of cost to be put
aside for depreciation, will be less in case of the high-class than in
the low-class engine, while the former will also require less boiler
power.

Against these advantages are to be set the greater first cost of the
automatic engine, and the consequent annual charge due to capital sunk.
These several items should all be fairly estimated when an engine is
to be bought, and the kind chosen accordingly. Let us take the item of
fuel, for instance, and let us suppose this fuel to cost four dollars
per ton at the place where the engine is run. Suppose the engine to be
capable of developing one hundred horse-power, and that it consumes five
pounds of coal per hour per horse-power, and runs ten hours per day:
this would necessitate the supply of two and one-half tons per day at
a cost of ten dollars per day. To be really economical, therefore, any
improvement which would effect a saving of one pound of coal per hour
per horse-power must not cost a greater sum per horse-power than that on
which the cost of the difference of the coal saved (one pound of coal
per hour per horse-power, which would be 1,000 pounds per day) for, say,
three hundred days, three hundred thousand (300,000) pounds, or one
hundred and fifty tons (or six hundred dollars), would pay a fair
interest.

Assuming that the mill owner estimates his capital as worth to him ten
per cent, per annum, then the improvement which would effect the above
mentioned saving must not cost more than six thousand dollars, and so
on. If, instead of being run only ten hours per day, the engine is run
night and day, then the outlay which it would be justifiable to make to
effect a certain saving per hour would be doubled; while, on the other
hand, if an engine is run less than the usual time per day a given
saving per hour would justify a correspondingly less outlay.

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