at Langenberg, near Stettin, in Prussia.[23] The moss-meadows along the
river Oder, near which Langenberg is situated, are but a foot or so
higher at the surface than the medium level of this river, and are
subject to frequent and sudden inundations, so that draining and partial
drying of the peat are out of the question. The character of the peat is
unadapted to cutting by hand, since portions of it are pitchy and
crumble too easily to form good sods; and others, usually the lower
layers, at a depth of seven feet or more, are made up to a considerable
extent of quite firm reeds and flags, having the consistence of half
decayed straw. The earthy peat is manufactured after Challeton's method.
It is raised with a steam dredger of 20 horse power, and emptied into
flat boats, seven in number, which are drawn to the works by an endless
rope operated by horse power. The works themselves are situated on a
small sand hill in the middle of the moor, and communicate by canal with
the dredger and with the drying ground. A chain of buckets, working in
a frame 45 feet long, attached by a horizontal hinge to the top of the
machine house, reaches over the dock where the boats haul up, into the
rear end of the latter; and, as the buckets begin to raise the peat, the
boat itself is moved under the frame towards the house, until, with a
man's assistance, its entire load is taken up. The contents of one boat
are six square yards, with a depth of one foot, and a boat is emptied in
20 minutes time. Forty to forty-four boatloads are thus passed into the
pulverizing machine daily, by two chains of buckets.
The peat-mud falls from the buckets into a large wooden trough, which
branches into two channels, conducting to two large tubs standing side
by side. These tubs are 10 feet in diameter and 2 feet deep, and are
made of 2-inch plank. Within each tub is placed concentrically a
cylindrical sieve, or colander, 8 feet in diameter and 2 feet high, made
of 3/8 round iron, and it is within this that the peat is emptied. The
peat is stirred and forced through the meshes of the sieve by four arms
of a shaft that revolves 20 times per minute, the arms carrying at their
extremities stiff vertical brooms, which rub the inside of the sieve.
In these four tubs the peat is pulverized under addition of water; the
fine parts pass the sieves, while the latter retain the coarse fibres,
roots, etc. The peat-mud flows from the tubs into mills, made like a
flour mill, but the "stones" constructed of hard wood. The "stones" have
a diameter of 8 feet 6 inches; the lower is 8 inches; the upper 21
inches thick. The pressure of the upper "stone" is regulated by
adjusting the level of the discharging channel, so that the "stone" may
be more or less buoyed, or even fully floated by the water with which it
is surrounded.
The peat-substance, which is thus finely ground, gathers from the four
mills into a common reservoir whence it is lifted by a centrifugal pump
into a trough, which distributes it over the drying ground.
The drying ground consists of the surface formed by grading the sand
hill, on which the works are built, and includes about 30 English acres.
This is divided into small plots, each of which is enclosed on three
sides with a wall of earth, and on the fourth side by boards set on
edge. Each plot is surrounded by a ditch to carry off water, and by
means of portable troughs, the peat is let on from the main channel. The
peat-slime is run into these beds to the depth of 20 to 22 inches, an
acre being covered daily. After 4 to 8 days, according to the weather,
the peat has lost so much water, which, rapidly soaks off through the
sand, that its surface begins to crack. It is then thoroughly trodden by
men, shod with boards 5 inches by 10 inches, and after 6 to 8 days more,
it is cut with sharp spades into sods. The peats are dried in the usual
manner.
The works at Langenberg yielded, in 1863, as the result of the
operations of 60 days of 12 hours each, 125,000 cwt. of marketable peat.
It is chiefly employed for metallurgical purposes, and sells at 3-1/3
Silver-groschen, or nearly 8 cents per cwt. The specific gravity of the
peat ranges from 0.73 to 0.90.
_Roberts' Process._
In this country attempts have been made to apply Challeton's method. In
1865, Mr. S. Roberts, of Pekin, N. Y., erected machinery at that place,
which was described in the "Buffalo Express," of Nov. 17, 1865, as
follows:--
"In outward form, the machine was like a small frame house on wheels,
supposing the smoke-stack to be a chimney. The engine and boiler are of
locomotive style; the engine being of thirteen horse power. The
principal features of the machine are a revolving elevator and a
conveyer. The elevator is seventy-five feet long, and runs from the top
of the machine to the ground, where the peat is dug up, placed on the
elevator, carried to the top of the machine, and dropped into a
revolving wheel that cuts it up; separates from it all the coarse
particles, bits of sticks, stones, etc.; and throws them to one side.
The peat is next dropped into a box below, where water is passed in,
sufficient to bring it to the consistency of mortar. By means of a slide
under the control of the engineer, it is next sent to the rear of the
machine, where the conveyer, one hundred feet long, takes it, and
carries it within two rods of the end; at which point the peat begins to
drop through to the ground to the depth of about four or five inches.
When sufficient has passed through to cover the ground to the end of the
conveyer,--two rods,--the conveyer is swung around about two feet, and
the same process gone through, as fast as the ground under the elevator,
for the distance of two rods in length and two feet in width gets
covered, the elevator being moved. At each swing of the elevator, the
peat just spread is cut into blocks (soft ones, however) by knives
attached to the elevator. It generally takes from three to four weeks
before it is ready for use. It has to lie a week before it is touched,
after the knives pass through it; when it is turned over, and allowed to
lie another week. It has then to be taken up, and put in a shed, and
within a week or ten days can be used, although it is better to let it
remain a little longer time. The machine can spread the peat over
eighteen square rods of ground--taking out one square rod of
peat--without being moved. After the eighteen rods are covered, the
machine is moved two rods ahead, enabling it to again spread a
semicircular space of some thirty-two feet in width by eighteen rods in
length. The same power, which drives the engine, moves the machine. It
is estimated by Mr. Roberts, that, by the use of this machine, from
twenty to thirty tons of peat can be turned out in a day."
Mr. Roberts informs us that he is making (April 1866,) some
modifications of his machinery. He employs a revolving digger to take up
the peat from the bed, and carry it to the machine. At the time of going
to press, we do not learn whether he regards his experiments as leading
to a satisfactory conclusion, or otherwise.
_Siemens' method._
Siemens, Professor of Technology, in the Agricultural Academy, at
Hohenheim, successfully applied the following mode of preparing peat for
the Beet Sugar Manufactory at Boeblingen, near Hohenheim, in the year
1857. Much of the peat there is simply cut and dried in the usual
manner. There is great waste, however, in this process, owing to the
frequent occurrence of shells and clay, which destroy the coherence of
the peat. Besides, a large quantity of material accumulates in the
colder months, from the ditches which are then dug, that cannot be
worked in the usual manner at that time of the year. It was to economize
this otherwise useless material that the following process was devised,
after a failure to employ Challeton's method with profit.
In the first place, the peat was dumped into a boarded cistern, where it
was soaked and worked with water, until it could be raised by a chain of
buckets into the pulverizer.
The pulverization of the peat was next effected by passing it through a
machine invented by Siemens, for pulping potatoes and beets. This
machine, (the same we suppose as that described and figured in Otto's
Landwirthschaftliche Gewerbe), perfectly breaks up and grates the peat
to a fine pulp, delivers it in the consistency of mortar into the
moulds, made of wooden frames, with divisions to form the peats. The
peat-paste is plastered by hand into these moulds, which are immediately
emptied to fill again, while the blocks are carried away to the drying
ground where they are cured in the ordinary style without cover.
In this simple manner 8 men were able to make 10,000 peats daily, which,
on drying, were considerably denser and harder than the cut peat.
The peat thus prepared, cost about one-third more than the cut peat.
Siemens reckoned, this greater cost would be covered by its better
heating effect, and its ability to withstand transportation without
waste by crumbling.
b. _Condensation of fibrous peat._
_Weber's method._
At Staltach, in Southern Bavaria, Weber has established an extensive
peat works, of which Vogel has given a circumstantial account.[24] The
peat at Staltach is very light and fibrous, but remarkably free from
mineral matters, containing less than 2 _per cent._ of ash in the
perfectly dry substance. The moor is large, (475 acres), and the peat is
from 12 to 20 feet in depth. The preparation consists in converting the
fresh peat into pulp or paste, forming it into moulds and drying it; at
first by exposure to the air at ordinary temperature, and finally, by
artificial heat, in a drying house constructed for the purpose.
The peat is cut out by a gang of men, in large masses, cleared of coarse
roots and sticks, and pushed on tram wagons to the works, which, are
situated lower than the surface of the bog. Arrived at the works, the
peat is carried upon an inclined endless apron, up to a platform 10 feet
high, where a workman pushes it into the pulverizing mill, the
construction of which is seen from the accompanying cut. The vertical
shaft _b_ is armed with sickle-shaped knives, _d_, which revolve between
and cut contrary to similar knives _c_, fixed to the interior of the
vessel. The latter is made of iron, is 3-1/2 feet high, 2 feet across at
top and 1-1/2 feet wide at the bottom. From the base of the machine at
_g_, the perfectly pulverized or minced peat issues as a stiff paste. If
the peat is dry, a little water is added. Vogel found the fresh peat to
contain 90 _per cent._, of water, the pulp 92 _per cent._ Weber's
machine, operated by an engine of 10 horse power, working usually to
half its capacity only, reduced 400 cubic feet of peat per hour, to the
proper consistency for moulding.
[Illustration: Fig. 10.--WEBER'S PEAT MILL.]
Three modes of forming the paste into blocks have been practiced. One
was in imitation of that employed with mud-peat. The paste was carried
by railway to sheds, where it was filled by hand into moulds 17 inches
by 7-1/4 by 5-1/2 inches, and put upon frames to dry. These sheds
occupied together 52,000 square feet, and contained at once 200,000
peats. The peats remained here 8 to 14 days or more, according to the
weather, when they were either removed to the drying house, or piled in
large stacks to dry slowly out-of-doors. The sheds could be filled and
emptied at least 12 times each season, and since they protected from
light frosts, the season began in April and lasted until November.
The second mode of forming the peat was to run off the pulp into large
and deep pits, excavated in the ground, and provided with drains for
carrying off water. The water soaked away into the soil, and in a few
weeks of good weather, the peat was stiff enough to cut out into blocks
by the spade, having lost 20 to 25 _per cent._ of its water, and 15 _per
cent._ of its bulk. The blocks were removed to the drying sheds, and set
upon edge in the spaces left by the shrinking of the peats made by the
other method. The working of the peat for the pits could go on, except
in the coldest weather, as a slight covering usually sufficed to protect
them from frost.
Both of these methods have been given up as too expensive, and are
replaced, at present, by the following:
In the third method the peat-mass falls from the mill into a hopper,
which directs it between the rolls _A B_ of fig. 11, (see next page).
The roll _A_ has a series of boxes on its periphery _m m_, with movable
bottoms which serve as moulds. The peat is carried into these boxes by
the rolls _c c_. The iron projections _n n_ of the large roll _B_, which
work cog-like into the boxes, compress the peat gently and, at last, the
eccentric p acting upon the pin _z_, forces up the movable bottom of the
box and throws out the peat-block upon an endless band of cloth, which
carries it to the drying place.
The peats which are dried at first under cover and therefore slowly,
shrink more evenly and to a greater extent than those which are allowed
to dry rapidly. The latter become cracked upon the surface and have
cavities internally, which the former do not. This fact is of great
importance for the density of the peat, for its usefulness in producing
intense heat, and its power to withstand carriage.
[Illustration: Fig. 11--WEBER'S PEAT MOULDING MACHINE.]
The _complete drying_ is, on the other hand, by this method, a much
slower process, since the dense, fissureless exterior of the peats
hinders the escape of water from within. It requires, in fact, several
months of ordinary drying for the removal of the greater share of the
water, and at the expiration of this time they are still often moist in
the interior.
Artificial drying is therefore employed to produce the most compact,
driest, and best fuel.
Weber's _Drying house_ is 120 feet long and 46 feet wide. Four large
flues traverse the whole length of it, and are heated with the pine
roots and stumps which abound in the moor. These flues are enclosed in
brick-work, leaving a narrow space for the passage of air from without,
which is heated by the flues, and is discharged at various openings in
the brick-work into the house itself, where the peat is arranged on
frames. The warm air being light, ascends through the peat, charges
itself with moisture, thereby becomes heavier and falls to the floor,
whence it is drawn off by flues of sheet zinc that pass up through the
roof. This house holds at once 300,000 peats, which are heated to 130 deg.
to 145 deg. F., and require 10 to 14 days for drying.
The effect of the hot air upon the peat is, in the first place, to
soften and cause it to swell; it, however, shortly begins to shrink
again and dries away to masses of great solidity. It becomes almost
horny in its character, can be broken only by a heavy blow, and endures
the roughest handling without detriment. Its quality as fuel is
correspondingly excellent.
The effects of the mechanical treatment and drying on the Staltach peat,
are seen from the subjoined figures:
_Lbs.
_Specific per Cubic _Per cent of
Gravity._ Foot._ Water._
Peat, raised and dried in usual way, 0.24 15 18 to 20
Machine-worked and hot-dried 0.65 35 12
Vogel estimates the cost of peat made by Weber's method at 5 Kreuzers
per (Bavarian) hundred weight, while that of ordinary peat is 13-1/2
Kreuzers. Schroeder, in his comparison of machine-wrought and ordinary
peat, demonstrates that the latter can be produced much cheaper than was
customary in Bavaria, in 1859, by a better system of labor.
Weber's method was adopted with some improvements in an extensive works
built in 1860, by the Government of Baden, at Willaringen, for the
purpose of raising as much fuel as possible, during the course of a
lease that expired with the year 1865.
[Illustration: Fig. 12.--GEYSSER'S PEAT MACHINE.]
_Gysser's method._[25]--Rudolph Gysser, of Freiburg, who was charged
with the erection of the works at Willaringen just alluded to, invented
a portable hand-machine on the general plan of Weber, but with
important improvements; and likewise omitted and varied some details of
the manufacture, bringing it within the reach of parties of small means.
In the accompanying cuts, (figs. 12, 13, and 14), are given an elevation
of Gysser's machine, together with a bird's-eye view and vertical
section of the interior mechanism.
[Illustration: Fig. 13.]
[Illustration: Fig. 14.]
It consists of a cast iron funnel _c d i_ of the elevation, (fig. 12),
having above a sheet iron hopper _a b_ to receive the peat, and within a
series of six knives fastened in a spiral, and curving outwards and
downwards, (figs. 13 and 14); another series of three similar knives is
affixed to a vertical shaft, which is geared to a crank and turned by a
man standing on the platform _j k_; these revolving knives curve upwards
and cut between and in a direction contrary to the fixed knives; below
the knives, and affixed to the shaft a spiral plate of iron and a
scraper _m_, (fig. 13), serve to force the peat, which has been at once
minced and carried downwards by the knives, as a somewhat compressed
mass through the lateral opening at the bottom of the funnel, whence it
issues as a continuous hollow cylinder like drain-tile, having a
diameter of four inches. The iron cone _i_, held in the axis of the
opening by the thin and sharp-edged support _g h_, forms the bore of the
tube of peat as it issues. Two men operate the machine; one turning the
crank, which, by suitable gearing, works the shaft, and the other
digging and throwing in the peat. The mass, as it issues from the
machine, is received by two boys alternately, who hold below the opening
a semi-cylindrical tin-plate shovel, (fig. 15), of the width and length
of the required peats, and break or rather wipe them off, when they
reach the length of 14 inches.
[Illustration: Fig. 15.]
[Illustration: Fig. 16.]
The formed peats are dried in light, cheap and portable houses, Fig. 17,
each of which consists of six rectangular frames supported one above
another, and covered by a light roof. The frames, Fig. 16, have square
posts at each corner like a bedstead, and are made by nailing light
strips to these posts. The tops of these posts are obtusely beveled to
an edge, and at the bottom they are notched to correspond. The direction
of the edges and of the notches in two diagonally opposite posts, is at
right angles to that of the other two. By this construction the frames,
being of the same size, when placed above each other, fit together by
the edges and notches of their posts into a structure that cannot be
readily overturned. The upper frame has a light shingled roof, which
completes the house. Each frame has transverse slats, cast in plaster of
Paris, 20 in number, which support the peats. The latter being tubular,
dry more readily, uniformly, and to a denser consistence than they could
otherwise.
The machine being readily set up where the peat is excavated, the labor
of transporting the fresh and water-soaked material is greatly reduced.
The drying-frames are built up into houses as fast as they are filled
from the machine. They can be set up anywhere without difficulty,
require no leveling of the ground, and, once filled, no labor in turning
or stacking the peats is necessary; while the latter are insured against
damage from rain. These advantages, Gysser claims, more than cover their
cost.
[Illustration: Fig. 17.]
The daily production of a machine operated by two men with the
assistance of one or two boys, is 2500 to 3000 peats, which, on drying,
have 9-1/2 to 10 inches of length, and 2-1/2 in diameter, and weigh, on
the average, one pound each.
c.--_Condensation of peat of all kinds._--_Weber's method with modified
machinery._
[Illustration: Fig. 18.--SCHLICKEYSEN'S PEAT MILL.]
_Schlickeysen's Machine._[26]--This machine has been in use in Germany
since 1860, in the preparation of peat. It appears to have been
originally constructed for the working and moulding of clay for making
bricks. The principle of its operation is identical with that of Weber's
process. The peat is finely pulverized, worked into a homogenous mass,
and moulded into suitable forms. Like Gysser's machine, it forces the
peat under some pressure through a nozzle, or, in the larger kinds
through several nozzles, whence it issues in a continuous block or pipe
that is cut off in proper lengths, either by hand or by mechanism It
consists of a vertical cylinder, through the axis of which revolves a
shaft, whereon are fastened the blades, whose edges cut and whose
winding figure forces down the peat. The blades are arranged nearly, but
not exactly, in a true spiral; the effect is therefore that they act
unequally upon the mass, and thus mix and divide it more perfectly. No
blades or projections are affixed to the interior of the cylinder.
Above, where the peat enters into a flaring hopper, is a scraper, that
prevents adhesion to the sides and gives downward propulsion to the
peat. The blades are, by this construction, very strong, and not liable
to injury from small stones or roots, and effectually reduce the
toughest and most compact peat.
Furthermore, addition of water is not only unnecessary in any case, but
the peat may be advantageously air-dried to a considerable extent before
it enters the machine. Wet peat is, indeed, worked with less expenditure
of power; but the moulded peats are then so soft as to require much care
in the handling, and must be spread out in single courses, as they will
not bear to be placed one upon another. Peat, that is somewhat dry,
though requiring more power to work, leaves the machine in blocks that
can be piled up on edge and upon each other, six or eight high, without
difficulty, and require, of course, less time for curing.
The cut, (fig. 18), represents one of Schlickeysen's portable
peat-mills, with elevator for feeding, from which an idea of the
pulverizing arrangements may be gathered.
In Livonia, near Pernan, according to Leo, two of Schlickeysen's
machines, No. 6, were put in operation upon a purely fibrous peat. They
were driven by an engine of 12 horse-power. The peat was plowed, once
harrowed, then carted directly to the hopper of the machine. These two
machines, with 26 men and 4 horses, produced daily 60,000 peats = 7500
cubic feet. 100 cubic feet of these peats were equal in heating effect
to 130 cubic feet of fir-wood, and cost but two-thirds as much. The
peats were extremely hard, and dried in a few days sufficiently for use.
In 1864, five large Schlickeysen machines were in operation at one
establishment at St. Miskolz, in Hungary.
The smaller sizes of Schlickeysen's machine are easily-portable, and
adapted for horse or hand-power.
_Leavitt's Peat-condensing and Moulding Mill._[27]--In this country, Mr.
T. H. Leavitt, of Boston, has patented machinery, which is in operation
at East Lexington, Mass., at the works of the Boston Peat Company. The
process is essentially identical with that of Weber, the hot-drying
omitted. The fresh peat is pulverized or cut fine, moulded into blocks,
and dried on light frames in the open air. The results claimed by Mr.
Leavitt, indicate, that his machine is very efficacious.
It consists, principally, of a strong box or cistern, three feet in
diameter, and six feet high, the exterior of which, with its gearing, is
shown in figure 19. The mill is adapted to be driven by a four
horse-power engine.
"The upper portion of the box is divided by a series of horizontal
partitions, the upper ones being open latticework, and the lower ones
perforated with numerous holes. The upright shaft, which rotates in the
centre of the box, carries a series of arms or blades, extending
alternately on opposite sides, and as these revolve, they cut the peat,
and force it through the openings in the diaphragms. The lower portion
of the box, in place of complete partitions, has a series of corrugated
shelves extending alternately from opposite sides, and the peat is
pressed and scraped from these by a series of arms adapted to the work.
By this series of severe operations the air-bubbles are expelled from
the peat, and it is reduced to a homogeneous paste. When it arrives at
the bottom of the box, it is still further compressed by the converging
sides of the hopper, and it is received in light moulds which are
carried on an endless belt." Mr. Leavitt has patented the use of
powdered peat for the purpose of preventing the prepared peat from
adhering to the moulds.
[Illustration: Fig. 19.--LEAVITT'S PEAT MILL.]
This mill, it is asserted, will condense 40 tons of crude peat daily,
which, at Lexington, is estimated to yield 10 to 14 tons of dry
merchantable fuel. The cost of producing the latter is asserted to be
less than $2.00 per ton; while its present value, in Boston, is $10 per
ton. It requires seven men, three boys, and two horses to dig, cart,
mill, and spread the peat. The machine costs $600, the needful
buildings, engine, etc., from $2000 to $3000. The samples of peat,
manufactured by this machine, are of excellent quality. The drying in
the open air is said to proceed with great rapidity, eight or ten days
being ordinarily sufficient in the summer season. The dry peat, at
Lexington, occupies one-fourth the bulk, and has one-fourth to one-third
the weight of the raw material; the latter, as we gather, being by no
means saturated with water, but well drained, and considerably dry,
before milling.
_Ashcroft & Betteley's Machinery._
The American Peat Company, of Boston, are the owners of five patents,
taken out by Messrs. Ashcroft & Betteley, for peat machinery. They claim
to "make fuel equal to the best English Cannel coal," and really do make
a very good peat, though with a rather complicated apparatus. The
following statement is derived from the circular issued by the company.
The machinery consists of the following parts:--
_First._--TRITURATING MACHINE--36 inches diameter, 4 feet 6 inches high,
with arms both on the inside of this cylinder and on the upright
revolving shaft. In the bottom of the cylinder or tub a large slide gate
is fitted to work with a lever, so that the peat may be discharged, at
pleasure, into the Combing Machine, which is placed directly under this
Triturator.
_Second._--COMBING MACHINE--Semi-circular vessel 6 feet long and 3 feet
6 inches in diameter. Inside, a shaft is placed, which is provided with
fingers, placed one inch apart; the fingers to be 20 inches long, so as
to reach within 2 inches of the bottom and sides of this vessel. Another
shaft, of the same size and dimensions, is placed at an angle of 45 deg., 26
inches from the first shaft, with arms of the same dimensions placed
upon this shaft, with the same spaces, and so placed that this set of
arms pass between the first set, both shafts revolving in the same
direction; the second shaft mentioned being driven at double the speed
of the first. At the bottom of this Combing Machine is to be fixed a
gate, to be operated by a lever, to deliver, at pleasure, the cleansed
peat into the Manipulator or Kneading Machine.
_Third._--MANIPULATOR.--A Tube of iron 7 feet long and 16 inches
diameter, fitted with a shaft, with flanges upon it, to gain 6 inches in
each revolution.
_Fourth._--CONVEYOR.--This Conveyor, to be made with two endless chains
and buckets of iron, with a driving shaft. The hopper, to receive the
peat when first taken from the bog, to be placed below the surface of
the ground, so that the top edge of the hopper may be level with the
surface, that the peat may be dumped from the car by which it is taken
from the bog, and carried to the hopper without hand labor; and this
conveyor to be so arranged that the peat will be delivered into the
Triturator without hand labor.
_Fifth._--CONVEYOR.--Another conveyor, precisely like the one above
described, is to be placed so as to convey the peat from the Manipulator
into the Tank without hand labor.
_Sixth._--TANK.--A tank 35 feet high and 15 feet in diameter; the bottom
of this tank is made sloping towards the sides, at an angle of 65 deg., and
is covered with sole tile or drain tile, and the entire inside of this
tank is also ribbed with these tile; the ends of these pipes of tile
being left open, so that the water which percolates through the pores of
the tile, by the pressure of the column of peat, will pass out at the
bottom, through the false floor of the tank into the drain, and the
solid peat is retained in the tank. A worm is fixed in the bottom of
this tank, which is driven by machinery, which forces out the peat in
the form of brick, which are cut to any length, and stacked up in sheds,
for fuel, after it is fully dried by the air.
[Illustration: Fig. 20.--VERSMANN'S PEAT PULVERIZER.]
_Versmann's Machine_[28]--This machine, see Fig. 20, was invented by a
German engineer, in London, and was patented there in Sept., 1861. It
consists of a funnel or hollow cone _b_, of boiler-plate, from one to
two feet in diameter at top, and perforated with 200 to 300 small holes
per square foot of surface, within which rapidly revolves an iron cone
_a_, carrying on its circumference two spiral knives. The peat thrown in
at the top of the funnel is carried down by the knives, and at once cut
or broken and forced in a state of fine division through the holes of
the funnel, as through a colander. The fine peat collects on the
inclined bottom of the chamber _d_, whence it is carried by means of
Archimedean screws to a moulding machine. The coarse stuff that escapes
pulverization falls through _e_ into the cavity _c_. It may be employed
as fuel for the engine, or again put through the machine.
This machine effects a more perfect pulverization of the peat, than any
other hitherto described. This extreme division is, however, unnecessary
to the perfection of the product, and is secured at great expense of
power. Through the opening at the bottom of the funnel, much
unpulverized peat finds its way, which must be continually returned to
the machine. Again, stones, entering the funnel, are likely to break or
damage the spiral knives, which bear close to the walls of the funnel.
The pulverized peat must be moulded by hand, or by a separate
instrument.
_Buckland's Machine_[29] is identical in principle with Versmann's, and
in construction differs simply in the fact of the interior cone having
spiral grooves instead of spiral knives. This gives greater simplicity
and durability to the machine. It appears, however, to require too much
power to work it, and can hardly equal other machines in the quantity of
product it will deliver for a given expenditure. The ground peat yielded
by it, must be moulded by hand, or by other machinery. This machine, we
understand, has been tried near Boston, and abandoned as uneconomical.
The machines we have described are by no means all that have been
proposed and patented. They include, however, so the author believes,
all that have been put into actual operation, at the date of this
writing, or that present important peculiarities of construction.
The account that has been given of them will serve to illustrate what
mechanism has accomplished hitherto in the manufacture of peat-fuel, and
may save the talent of the American inventor from wasting itself on what
is already in use, or having been tried, has been found wanting. At
present, very considerable attention is devoted to the subject.
Scarcely a week passes without placing one or more Peat-mill patents on
record. In this treatise our business is with what has been before the
public in a more or less practical way, and it would, therefore, be
useless to copy the specifications of new, and for the most part untried
patents, which can be found in the files of our mechanical Journals.
14. _Artificial Drying of Peat._
As we have seen, air-dry peat contains 20 to 30 and may easily contain
50 _per cent._ of water, and the best hot-made machine peat contains 15
_per cent._ When peat is used as fuel in ordinary furnaces, this water
must be evaporated, and in this process a large amount of heat is
consumed, as is well understood. It is calculated, that the temperature
which can be produced in perfectly burning full-dried peat, compares
with that developed in the combustion of peat containing water, as
follows:--
Pyrometric effect of perfectly dry peat 4000 deg. F.
" " peat with 30 _per cent._ of water 3240 deg. "
" " " 50 " " 2848 deg. "
But, furthermore, moist or air-dried peat does not burn in ordinary
furnaces, except with considerable waste, as is evident from the
smokiness of its flame. When air-dried peat is distilled in a retort, a
heavy yellow vapor escapes for some time after the distillation begins,
which, obviously, contains much inflammable matter, but which is so
mixed and diluted with steam that it will not burn at all, or but
imperfectly. It is obvious then, that when a high temperature is to be
attained, anhydrous or full-dried peat is vastly superior to that which
has simply been cured in the open air.
Notice has already been made of Weber's drying-house, the use of which
is an essential part of his system of producing peat-fuel. Various other
arrangements have been proposed from time to time, for accomplishing
the same object. It appears, however, that in most cases the
anticipations regarding their economy have not been fully realized. It
is hardly probable, that artificially dried peat can be employed to
advantage except where waste heat is utilized in the operation.
A point of the utmost importance in reference to the question of drying
peat by artificial warmth is this, viz.: Although the drying may be
carried so far as to remove the whole of the water, and produce an
absolutely dry fuel, the peat absorbs moisture from the air again on
exposure; so that drying to less than 15 _per cent._ of water is of no
advantage, unless the peat is to be used immediately, or within a few
days. The employment of highly dried peat is consequently practicable
only for smelting-works, locomotives, and manufacturing establishments,
where it may be consumed as fast as it is produced.
A fact likewise to be regarded is, that artificial drying is usually
inapplicable to fresh peat. The precautions needful in curing peat have
already been detailed. Above all, slow drying is necessary, in order
that the blocks shrink uniformly, without cracking and warping in such a
way as to seriously injure their solidity and usefulness. In general,
peat must be air-dried to a considerable extent before it can be
kiln-dried to advantage. If exposed to dry artificial heat, when
comparatively moist, a hard crust is formed externally, which greatly
hinders subsequent desiccation. At the same time this crust, contracting
around the moist interior, becomes so rifted and broken, that the
ultimate shrinkage and condensation of the mass is considerably less
than it would have been had the drying proceeded more slowly.
Besides Weber's drying oven, the fuel for firing which is derived
without cost from the stumps and roots of trees that are abundant on the
moor, at Staltach, and which are thus conveniently disposed of, we have
briefly to notice several other drying kilns with regard to all of
which, however, it must be remarked, that they can only be employed with
profit, by the use of waste heat, or, as at Staltach, of fuel that is
comparatively worthless for other purposes.
[Illustration: Fig. 21.--CARINTHIAN PEAT DRYING-KILN.]
The _Peat Kilns_ employed at Lippitzbach, in Carinthia, and at Neustadt,
in Hanover, are of the kind shown in fig. 21. The peat with which the
main chamber is filled, is heated directly by the hot gases that arise
from a fire made in the fire-place at the left. These gases first enter
a vault, where they intermingle and cool down somewhat; thence they
ascend through the openings of the brick grating, and through the mass
of peat to the top of the chamber. On their way they become charged
with vapor, and falling, pass off through the chimney, as is indicated
by the arrows. The draught is regulated by the damper on the top of the
chimney. To manage the fire, so that on the one hand the chimney is
sufficiently heated to create a draught, and on the other waste of fuel,
or even ignition of the peat itself is prevented, requires some care.
In _Welkner's Peat Kiln_[30] (fig. 22) the peat, previously air-dried,
is exposed to a stream of hot air, until it is completely desiccated,
and the arrangement is such, that air-dried peat may be thrown in at the
top, and the hot-dried fuel be removed at the bottom, continuously.
In the cut, _A_ represents the section of a wooden cylinder about 10
feet wide and 6-1/2 feet deep, which surmounts a funnel of iron plate
_A'_. The mouth of the funnel is closed by a door _n_; about 20 inches
above the door the pipe _B_, which conducts hot air, terminates in the
ring _a a_, through the holes in which, _e e_, it is distributed into
the funnel filled with peat. The air is driven in by a blower, and is
heated by circulating through a system of pipes, which are disposed in
the chimney of a steam boiler. From time to time a quantity of dried
peat is drawn off into the wagon _D_, which runs on rails, and a similar
amount of undried peat is thrown in above.
According to Welkner, a kiln of the dimensions stated, which cost, about
$1800 gold, is capable of desiccating daily ten tons of peat with 20
_per cent._ of water, using thereby 2000 cubic feet of air of a
temperature of 212 deg. F. When the air is heated by a fire kept up
exclusively for that purpose, 10 _per cent._ of the dried peat, or its
equivalent, is consumed in the operation. At the Alexis Smelting Works,
near Lingen, in Hanover, this peat kiln furnishes about half the fuel
for a high furnace, in which bog iron ore is smelted. The drying costs
but little, since half the requisite heat is obtained from the waste
heat of the furnace itself.
[Illustration: Fig. 22.--WELKNER'S PEAT DRYING KILN.]
The advantages of this drying kiln are, that it is cheap in construction
and working; dries gradually and uniformly; occupies little ground, and
runs without intermission.
Other drying ovens are described in Knapp's _Lehrbuch_ der _Chemischen
Technologie_, 3. Aufl. Bd. 1, Theil 1, pp. 178-9; _Jahrbuch der
Bergakademien Schemnitz_ und _Leoben_, 1860, p. 108, 1861, p. 55;
Wagner's _Jahresbericht der Chemischen Technologie_, 1863, p. 748;
Zerrenner's _Metallurgische Gasfeuerung in Oesterreich_; Tunner's
_Stabeisen- und Stahlbereitung_, 2. Auflage, Bd. I, pp. 23-25.
15. _Peat Coal, or Coke._
When peat is charred, it yields a coal or coke which, being richer in
carbon, is capable of giving an intenser heat than peat itself, in the
same way that charcoal emits an intenser heat in its combustion than the
wood from which it is made.
Peat coal has been and is employed to some extent in metallurgical
processes, as a substitute for charcoal, and when properly prepared from
good peat, is in no way inferior to the latter; is, in fact, better.
It is only, however, from peat which naturally dries to a hard and dense
consistency, or which has been solidified on the principles of
Challeton's and Weber's methods, that a coal can be made possessing the
firmness necessary for furnace use. Fibrous peat, or that condensed by
pressure, as in Exter's, Elsberg's, and the Lithuanian process, yields
by coking or charring, a friable coal comparatively unsuited for heating
purposes.
A peat which is dense as the result of proper mechanical treatment and
slow drying, yields a very homogeneous and compact coal, superior to any
wood charcoal, the best qualities weighing nearly twice as much per
bushel.
Peat is either charred in pits and heaps, or in kilns. From the
regularity of the rectangular blocks into which peat is usually formed,
it may be charred more easily in pits than wood, since the blocks admit
of closer packing in the heap, and because the peat coal is less
inflammable than wood coal. The heaps may likewise be made much smaller
than is needful in case of wood, viz.: six to eight feet in diameter,
and four feet high. The pit is arranged as follows: The ground is
selected and prepared as for charcoal burning, and should be elevated,
dry and compact. Three stout poles are firmly driven into the ground, so
as to stand vertically and equi-distant from each other, leaving within
them a space of six or eight inches. Around these poles the peats are
placed endwise, in concentric rows to the required width and height,
leaving at the bottom a number of air-channels of the width of one peat,
radiating from the centre outwards. The upper layers of peat are
narrowed in so as to round off the heap, which is first covered with dry
leaves, sods, or moss, over which a layer of soil is thrown. Dry, light
wood being placed at the bottom of the central shaft, it is kindled from
one of the canals at the bottom, and the charring is conducted as is
usual in making wood coal. The yield of coal ranges from 25 to 35 _per
cent._ of the peat by weight, and from 30 to 50 _per cent._ by volume.
Gysser recommends to mould the peat for charring in the form of
cylinders of 3 to 4 feet long, which, when dry, may be built up into a
heap like wood.
A great variety of ovens or kilns have been constructed for coking peat.
At the Gun Factory of Oberndorf, in Wirtemberg, peat is charred in the
kiln represented in the accompanying figure. The chamber is 9 feet high,
and 5-1/2 feet in diameter. The oven proper, _b b_, is surrounded by a
mantle of brick _a a_, and the space between, _c c_, is filled with
sand. Each wall, as well as the space, is 15 inches in thickness, and
the walls are connected by stones _d d_, at intervals of three feet.
Above the sole of the kiln, are three series of air holes, made by
imbedding old gun barrels in the walls. The door, which serves to empty
the kiln, is a plate of cast iron, the sides of its frame are wider than
the thickness of the wall, and by means of a board _e_, a box _m_ can be
made in front of the door, which is filled with sand to prevent access
of air. The peat is filled in through _i_, a channel being arranged
across the bottom of the kiln, from the door _f_, for kindling. When the
firing begins, the lowest air-holes and _i_ are open. When, through the
lower gun barrels, the peat is seen to be ignited, these are corked, and
those above are opened. When the smoke ceases to escape above, all the
openings are closed, _m_, is filled with sand, _i_ is covered over with
it, and the whole is left to cool. It requires about 8 to 9 days to
finish the charring of a charge. Several kilns are kept in operation, so
that the work proceeds uninterruptedly.
[Illustration: Fig. 23.--OBERNDORFER PEAT CHARRING KILN.]
[Illustration: Fig. 24.--WEBER'S CHARRING FURNACE.--TRANSVERSE SECTION.]
[Illustration: Fig. 25.--WEBER'S CHARRING FURNACE.--LONGITUDINAL
SECTION.]
At Staltach, Weber prepares peat coal in a cylinder of sheet iron, which
is surrounded by masonry. Below, it rests on a grating of stout wire.
Above, it has a cover, that may be raised by a pulley and on one side is
attached a small furnace, figure 24, the draught of which is kept up by
means of a blower, or an exhauster, and the flame and hot gases from
it, _which contain no excess of oxygen_, play upon the peat and
decompose it, expelling its volatile portions without burning or wasting
it in the slightest degree. The construction of the furnace, see fig.
24, is such, that the sticks of wood, which are employed for fuel, are
supported at their ends on shoulders in the brick-work, and the draught
enters the fire above instead of below. The wood is hereby completely
consumed, and by regulating the supply of air at _a_ (fig. 25) by a
sliding cover, and at _b_ by a register, the flame and current of air
which enters the cylinder containing the peat, is intensely hot and
accomplishes a rapid carbonization of the peat, but as before stated,
does not burn it. In this furnace the wood, which is cut of uniform
length, is itself the grate, since iron would melt or rapidly burn out;
and the coals that fall are consumed by the air admitted through c. The
hot gases which enter the cylinder filled with peat near its top, are
distributed by pipes, and, passing off through the grating at the
bottom, enter the surrounding brick mantle. Before reaching the
exhaustor, however, they pass through a cooler in which a quantity of
tar and pyroligneous acid is collected.
Weber's oven is 15 feet in diameter, and 3-1/2 feet high; 528 cubic feet
of peat may be coked in it in the space of 15 hours. The wood furnace is
2 feet in section, and consumes for the above amount of peat 3-1/2 cwt.
of wood. So perfectly are the contents of the iron cylinder protected
from contact of oxygen, that a rabbit placed within it, has been
converted into coal without the singeing of a hair; and a bouquet of
flowers has been carbonized, perfectly retaining its shape. The yield of
coal in Weber's oven is nearly 50 _per cent._ of the peat by weight.
Whenever possible, charring of peat should be carried on, or aided by
waste heat, or the heat necessary to coking should be itself economized.
In manufacturing and metallurgical establishments, a considerable
economy in both the drying and coking may often be effected in this
manner.
On the bog of Allen, in Ireland, we have an example of this kind. Peat
is placed in iron ovens in the form of truncated pyramids, the bottoms
of which consist of movable and perforated iron plates. The ovens are
mounted on wheels, and run on a rail track.
Five ovens filled with peat are run into a pit in a drying house, in
which blocks of fresh peat are arranged for drying. Each oven is
connected with a flue, and fire is applied. The peat burns below, and
the heat generated in the coking, warms the air of the drying house.
When the escaping smoke becomes transparent, the pit in which the ovens
stand is filled with water slightly above their lower edges, whereby
access of air to the burning peat is at once cut off. When cool, the
ovens are run out and replaced by others filled with peat. Each oven
holds about 600 lbs. of peat, and the yield of coal is 25 _per cent._ by
weight. The small yield compared with that obtained by Weber's method,
is due to the burning of the peat and the coal itself, in the draught of
air that passes through the ovens.
The author has carbonized, in an iron retort, specimens of peat prepared
by Elsberg's, Leavitt's, and Aschcroft and Betteley's processes.
Elsberg's gave 35, the others 37 _per cent._ of coal. The coal from
Elsberg's peat was greatly fissured, and could be crushed in the fingers
to small fragments. That from the other peats was more firm, and
required considerable exertion to break it. All had a decided metallic
brilliancy of surface.
16.--_Metallurgical Uses of Peat._
In Austria, more than any other country, peat has been employed in the
manufacture of iron. In Bavaria, Prussia, Wirtemberg, Hanover, and
Sweden, and latterly in Great Britain, peat has been put to the same
use. The general results of experience, are as follows:--
Peat can only be employed to advantage, when wood and mineral coal are
expensive, or of poor quality.
Peat can be used in furnaces adapted for charcoal, but not in those
built for mineral coal.
Good air-dry peat, containing 20 to 30 _per cent._ of water, in some
cases may replace a share of charcoal in the high furnace.
At Pillersee, in Austria, spathic iron ore has been reduced by a mixture
of fir-wood charcoal, and air-dry peat in the proportions of three
parts by bulk of the former to one of the latter. The use of peat was
found to effect a considerable saving in the outlay for fuel, and
enabled the production to be somewhat increased, while the excellence of
the iron was in no way impaired. The peat was of the best quality, and
was worked and moulded by hand.
When the ore is refractory and contains impurities that must be fluxed
and worked off in slag, a large proportion of air-dry peat cannot be
used to advantage, because the evaporation of the water in it consumes
so much heat, that the requisite temperature is not easily attained.
At Achthal, in Bavaria, air-dry peat was employed in 1860, to replace a
portion of the fir wood charcoal, which had been used for smelting an
impure clay-iron-stone: the latter fuel having become so dear, that peat
was resorted to as a make shift. Instead of one "sack," or 33 cubic feet
of charcoal, 24 cubic feet of charcoal and 15 cubic feet of peat were
employed in each charge, and the quantity of ore had to be diminished
thereby, so that the yield of pig was reduced, on the average, by about
17 _per cent._ In this case the quality of the iron, when worked into
bar, was injured by the use of peat, obviously from an increase of its
content of phosphorus. The exclusive use of air-dry peat as fuel in the
high furnace, appears to be out of the question.
At Ransko, in Bohemia, _kiln-dried peat_, nearly altogether free from
water, has been employed in a high furnace, mixed with but one-third its
bulk of charcoal, and in cupola furnaces for re-melting pig, full-dried
peat has been used alone, answering the purpose perfectly.
The most important metallurgical application of peat is in the refining
of iron.
Dried peat is extensively used in puddling furnaces, especially in the
so-called gas puddling furnaces, in Carinthia, Steyermark, Silesia,
Bavaria, Wirtemberg, Sweden, and other parts of Europe. In Steyermark,
peat has been thus employed for 25 years.
Air-dry peat is, indeed, also employed, but is not so well adapted for
puddling, as its water burns away a notable quantity of iron. It is one
of the best known facts in chemistry, that ignited iron is rapidly
oxidized in a stream of water-vapor, free hydrogen being at the same
time evolved.
In the high furnace, _peat-coal_, when compact and firm (not crumbly)
may replace charcoal perfectly, but its cost is usually too great.
When peat or peat-coal is employed in smelting, it must be as free as
possible from ash, because the ash usually consists largely of silica,
and this must be worked off by flux. If the ash be carbonate of lime, it
will, in most cases, serve itself usefully as flux. In hearth puddling,
it is important not only that the peat or peat-coal contain little ash,
but especially that the ash be as free as possible from sulphates and
phosphates, which act so deleteriously on the metal. The notion that, in
general, peat and peat charcoal are peculiarly adapted for the iron
manufacture, because they are free from sulphur and phosphorus, is
extremely erroneous. Not infrequently they contain these bodies in such
quantity, as to forbid their use in smelting.
In the gas-puddling furnace, or in the ordinary reverberatory, impure
peat may, however, be employed, since the ashes do not come in contact
with the metal. The only disadvantage in the use of peat in these
furnaces is, that the grates require cleaning more frequently, which
interrupts the fire, and, according to Tunner, increases the consumption
of fuel 8 to 10 _per cent._, and diminishes the amount of metal that can
be turned out in a given time by the same quantity.
Notwithstanding the interruption of work, it has been found, at
Rothburga, in Austria, that by substitution of machine-made and
kiln-dried peat for wood in the gas-puddling furnace, a saving of 50
_per cent._ in the cost of bar iron was effected, in 1860. What is to
the point, in estimating the economy of peat, is the fact that while 6.2
cubic feet of dry fir-wood were required to produce 100 lbs. of crude
bar, this quantity of iron could be puddled with 4.3 cubic feet of peat.
In the gas furnace, a second blast of air is thrown into the flame,
effecting its complete combustion; Dellvik asserts, that at Lesjoeforss,
in Sweden, 100 lbs. of kiln-dried peat are equal to 197 lbs. of
kiln-dried wood in heavy forging. In an ordinary fire, the peat would be
less effective from the escape of unburned carbon in the smoke.
In other metallurgical and manufacturing operations where flame is
required, as well as in those which are not inconvenienced by the
ingredients of its ash, it is obvious that peat can be employed when
circumstances conspire to render its use economical.
17.--_Peat as a source of illuminating gas._
Prof Pettenkofer, of Munich, was the first to succeed in making
illuminating gas from wood; and peat, when operated according to his
method, furnishes also a gas of good quality, though somewhat inferior
to wood-gas in illuminating power.
It is essential, that well-dried peat be employed, and the waste heat
from the retorts may serve in part, at least, for the drying.
The retorts must be of a good conducting material; therefore cast iron
is better than clay. They are made of the [symbol: D] form, and must be
relatively larger than those used for coal. A retort of two feet width,
one foot depth, and 8 to 9 feet length, must receive but 100 lbs. of
peat at a charge.
The quantity of gas yielded in a given time, is much greater than from
bituminous coal. From retorts of the size just named, 8000 to 9000 cubic
feet of gas are delivered in 24 hours. The exit pipes must, therefore,
be large, not less than 5 to 6 inches, and the coolers must be much more
effective than is needful for coal gas, in order to separate from it the
tarry matters.
The number of retorts requisite to furnish a given volume of gas, is
much less than in the manufacture from coal. On the other hand, the
dimensions of the furnace are considerably greater, because the
consumption of fuel must be more rapid, in order to supply the heat,
which is carried off by the copious formation of gas.
Gas may be made from peat at a comparatively low temperature, but its
illuminating power is then trifling. At a red heat alone can we procure
a gas of good quality.
The chief impurity of peat-gas is carbonic acid: this amounts to 25 to
30 _per cent._ of the gas before purification, and if the peat be
insufficiently dried, it is considerably more. The quantity of slaked
lime that is consumed in purifying, is therefore much greater than is
needed for coal-gas, and is an expensive item in the making of peat-gas.
While wood-gas is practically free from sulphur compounds and ammonia,
peat-gas may contain them both, especially the latter, in quantity that
depends upon the composition of the peat, which, as regards sulphur and
nitrogen, is very variable.
Peat-gas is denser than coal-gas, and therefore cannot be burned to
advantage except from considerably wider orifices than answer for the
latter, and under slight pressure.
The above statements show the absurdity of judging of the value of peat
as a source of gas, by the results of trials made in gas works arranged
for bituminous coal.
As to the yield of gas we have the following data, weights and measures
being English:--
100 lbs. of peat of medium quality from Munich, gave REISSIG 303 cub. ft.
" air-dry peat from Biermoos, Salzburg, gave RIEDINGER 305 "
" very light fibrous peat, gave REISSIG 379 to 430 "
" Exter's machine-peat, from Haspelmoor, gave 367 "
Thenius states, that, to produce 1000 English cubic feet of purified
peat-gas, in the works at Kempten, Bavaria, there are required in the
retorts 292 lbs of peat. To distil this, 138-1/2 lbs. of peat are
consumed in the fire; and to purify the gas from carbonic acid, 91-1/2
lbs. of lime are used. In the retorts remain 117 lbs. of peat coal, and
nearly 6 lbs. of tar are collected in the operation, besides smaller
quantities of acetic acid and ammonia.
According to Stammer, 4 cwt. of dry peat are required for 1000 cubic
feet of purified gas.
The quality of the gas is somewhat better than that made from bituminous
coal.
18.--_The examination of Peat as to its value for Fuel_, begins with and
refers to the air-dry substance, in which:
1.--Water is estimated, by drying the pulverized peat, at 212 deg., as long
as any diminution of weight occurs. Well-dried peat-fuel should not
contain more than 20 _per cent._ of water. On the other hand it cannot
contain less than 15 _per cent._, except it has been artificially dried
at a high temperature, or kept for a long time in a heated apartment.
2.--_Ash_ is estimated by carefully burning the dry residue in 1. In
first-rate fuel, it should amount to less than 3 _per cent._ If more
than 8 _per cent._, the peat is thereby rendered of inferior quality,
though peat is employed which contains considerably more.
3.--_Sulphur_ and _phosphorus_ are estimated by processes, which it
would be useless to describe here. Only in case of vitriol peats is so
much sulphur present, that it is recognizable by the suffocating fumes
of sulphuric acid or of sulphurous acid, which escape in the burning.
When peat is to be employed for iron manufacture, or under steam
boilers, its phosphorus, and especially its sulphur, should be
estimated, as they injure the quality of iron when their quantity
exceeds a certain small amount, and have a destructive effect on
grate-bars and boilers. For common uses it is unnecessary to regard
these substances.
4.--The quantity of _coal_ or _coke_ yielded by peat, is determined by
heating a weighed quantity of the peat to redness in an iron retort, or
in a large platinum crucible, until gases cease to escape. The neck of
the retort is corked, and when the vessel is cool, the coal is removed
and weighed. In case a platinum crucible is employed, it should have a
tight-fitting cover, and when gases cease to escape, the crucible is
quickly cooled by placing it in cold water.
Coal, or coke, includes of course the ash of the peat. This, being
variable, should be deducted, and the _ash-free coal_ be considered in
comparing fuels.
5.--The _density_ of peat-fuel may be ascertained by cutting out a block
that will admit of accurate measurement, calculating its cubic contents,
and comparing its weight with that of an equal bulk of water. To avoid
calculation, the block may be made accurately one or several cubic
inches in dimensions and weighed. The cubic inch of water at 60 deg. F.,
weighs 252-1/2 grains.
FOOTNOTES:
[10] The apparent specific gravity here means the weight of the
mass,--the air-filled cavities and pores included--as compared with an
equal bulk of water. The real specific gravity of the _peat itself_ is
always greater than that of water, and all kinds of peat will sink in
water when they soak long enough, or are otherwise treated so that all
air is removed.
[11] The "full" cubic foot implies a cubic foot having no cavities or
waste space, such as exist in a pile, made up of numerous blocks. If a
number of peat blocks be put into a box and shaken together, the empty
space between the more or less irregular blocks, may amount to 46 _per
cent._ of the whole; and when closely packed, the cavities amount to 30
_per cent._, according to the observations of _Wasserzieher_.
(_Dingler's Journal_, Oct., 1864, p. 118.) Some confusion exists in the
statements of writers in regard to this matter, and want of attention to
it, has led to grave errors in estimating the weight of fuel.
[12] The _waste space_ in peat and wood as commonly piled, is probably
included here in the statement, and is usually about the same in both;
viz.: not far from 40 _per cent._
[13] See note on the preceding page.
[14] _Der Torf, etc._, S. 43.
[15] See page 00.
[16] On account of the great convenience of the decimal weights and
measures, and their nearly universal recognition by scientific men, we
have adopted them here. The gramme = 15 grains; 5 degrees centigrade = 9
degrees Fahrenheit.
[17] Pliny, Hist. Nat. (Lib. XVI, 1) expresses his pity for the
"miserable people" living in East Friesland and vicinity in his day, who
"dug out with the hands a moor earth, which, dried more by wind than
sun, they used for preparing their food and warming their bodies:"
_captum manibus lutum ventis magis quam sole siccantis, terra cibos et
rigentia septembrione viscera sua urunt_.
As regards the "_misera gens_," it should be said that rich grain fields
and numerous flourishing villages have occupied for several centuries
large portions of the Duevel moor near Bremen.
[18] For further account and plans of this machine see Dingler's
Polytechnisches Journal, Bd. 176, S. 336.
[19] Described and figured in Bulletin de la Societe d'Encouragement,
August 1857, p. 513; also Dingler's Polytechnisches Journal, Bd. 146, S.
252.
[20] Berg- und Huettenmaennische Zeitung, 1859, Nr. 26.
[21] Henneberg's Journal fuer Landwirthschaft, 1858, S. 42.
[22] Henneberg's Journal fuer Landwirthschaft, 1858, p.p. 42 and 83.
[23] Dingler's Journal, Oct., 1864.
[24] Dingler's Polytechnisches Journal, Bd. 152, S. 272. See also,
Knapp, Lehrbuch der Chemischen Technologie, 3te Auflage, 1., 167.
[25] Der Torf; seine Bildung und Bereitungsweise, von Rudolph Gysser,
Weimar, 1864.
[26] Dingler's Journal, Bd. 165, S. 184.; und Bd. 172, S, 333.
[27] Scientific American, Feb. 10, 1866; also, Facts about Peat as Fuel,
by T. H. Leavitt, 2d Ed., Boston, p. 23.
[28] Dingler's Journal, Bd. 168, S. 306, und Bd. 172, S. 332.
[29] Described in Journal of the Society of Arts, 1860, p. 437.
[30] Bernemann & Kerl's Berg und Huettenmaennische Zeitung, 1862, 221.
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| Transcriber's Note: |
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| Typographical errors corrected in text: |
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| Page 6 Robert's changed to Roberts' |
| Page 24 Jaeckel changed to Jaeckel |
| Page 47 Poquonnock changed to Poquonock |
| Page 49 connexion changed to connection |
| Page 51 Poquonnock changed to Poquonock |
| Page 53 Poquonnock changed to Poquonock |
| Page 53 Russel changed to Russell |
| Page 62 subtances changed to substances |
| Page 67 Poquonnock changed to Poquonock |
| Page 89 5 changed to 4 |
| Page 89 Poquonnock changed to Poquonock |
| Page 90 Poquonnock changed to Poquonock |
| Page 91 Poquonnock changed to Poquonock |
| Page 116 artifical changed to artificial |
| Page 127 developes changed to develops |
| Page 149 Kneeding changed to Kneading |
| Page 165 The symbol looks like a D |
| lying on its back. |
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