HEATING POWER OF DIFFERENT KINDS OF FUEL.

Air-dry Wood 2800 " Peat 2500 3000 Perfectly dry Wood 3600 " " Peat 3000 4000 Air-dry Lignite or Brown Coal 3300 4200 Perfectly dry Lignite or Brown Coal 4000 5000 Bituminous Coal 3800 7000 Anthracite 7500 Wood Charcoal 6300 7500 Coke 6500 7600

4.—Modes of Burning Peat.

In the employment of peat fuel, regard must be had to its shape and bulk. Commonly, peat is cut or moulded into blocks or sods like bricks, which have a length of 8 to 18 inches; a breadth of 4 to 6 inches, and a thickness of 1-1/2 to 3 inches. Machine peat is sometimes formed into circular disks of 2 to 3 inches diameter, and 1 to 2 inches thickness and thereabouts. It is made also in the shape of balls of 2 to 3 inches diameter. Another form is that of thick-walled pipes, 2 to 3 inches in diameter, a foot or more long, and with a bore of one-half inch.

Flat blocks are apt to lie closely together in the fire, and obstruct the draft. A fire-place, constructed properly for burning them, should be shallow, not admitting of more than two or three layers being superposed. According to the bulkiness of the peat, the fire-place should be roomy, as regards length and breadth.

Fibrous and easily crumbling peat is usually burned upon a hearth, i. e. without a grate, either in stoves or open fire-places. Dense peat burns best upon a grate, the bars of which should be thin and near together, so that the air have access to every part of the fuel. The denser and tougher the peat, and the more its shape corresponds with that usual to coal, the better is it adapted for use in our ordinary coal stoves and furnaces.

5.—Burning of broken peat.



Broken peat—the fragments and waste of the cut or moulded blocks, and peat as obtained by plowing and harrowing the surface of drained peat-beds—may be used to advantage in the stair grate, fig. 1, which was introduced some years ago in Austria, and is adapted exclusively for burning finely divided fuel. It consists of a series of thin iron bars 3 to 4 inches wide, a, a, a, ... which are arranged above each other like steps, as shown in the figure. They are usually half as long as the grate is wide, and are supported at each end by two side pieces or walls, l. Below, the grate is closed by a heavy iron plate. The fuel is placed in the hopper A, which is kept filled, and from which it falls down the incline as rapidly as it is consumed. The air enters from the space G, and is regulated by doors, not shown in the cut, which open into it. The masonry is supported at u, by a hollow iron beam. Below, a lateral opening serves for clearing out the ashes. The effect of the fire depends upon the width of the throat of the hopper at u, which regulates the supply of fuel to the grate, and upon the inclination of the latter. The throat is usually from 6 to 8 inches wide, according to the nature of the fuel. The inclination of the grate is 40 to 45 deg. and, in general, should be that which is assumed by the sides of a pile of the fuel to be burned, when it is thrown up into a heap. This grate ensures complete combustion of fuel that would fall through ordinary grates, and that would merely smoulder upon a hearth. The fire admits of easy regulation, the ashes may be removed and the fuel may be supplied without checking the fire. Not only broken peat, but coal dust, saw dust, wood turnings and the like may be burned on this grate. The figure represents it as adapted to a steam boiler.

6.—Hygroscopic water of peat fuel.

The quantity of water retained by air-dried peat appears to be the same as exists in air-dried wood, viz., about 20 per cent. The proportion will vary however according to the time of seasoning. In thoroughly seasoned wood or peat, it may be but 15 per cent.; while in the poorly dried material it may amount to 25 or more per cent. When hot-dried, the proportion of water may be reduced to 10 per cent., or less.

When peat is still moist, it gathers water rapidly from damp air, and in this condition has been known to burst the sheds in which it was stored, but after becoming dry to the eye and feel, it is but little affected by dampness, no more so, it appears, than seasoned wood.

7.—Shrinkage.

In estimating the value and cost of peat fuel, it must be remembered that peat shrinks greatly in drying, so that three to five cords of fresh peat yield but one cord of dry peat. When the fiber of the peat is broken by the hand, or by machinery, the shrinkage is often much greater, and may sometimes amount to seven-eighths of the original volume.—Dingler's Journal, Oct. 1864, S. 68.

The difference in weight between fresh and dry peat is even greater. Fibrous peat, fresh from the bog, may contain ninety per cent. of water, of which seventy per cent. must evaporate before it can be called dry. The proportion of water in earthy or pitchy peat is indeed less; but the quantity is always large, so that from five to nine hundred weight of fresh peat must be lifted in order to make one hundred weight of dry fuel.

8.—Time of excavation, and drying.

Peat which is intended to be used after simply drying, must be excavated so early in the season that it shall become dry before frosty weather arrives: because, if frozen when wet, its coherence is destroyed, and on thawing it falls to a powder useless for fuel.

Peat must be dried with certain precautions. If a block of fresh peat be exposed to hot sunshine, it dries and shrinks on the surface much more rapidly than within: as a consequence it cracks, loses its coherence, and the block is easily broken, or of itself falls to pieces. In Europe, it is indeed customary to dry peat without shelter, the loss by too rapid drying not being greater than the expense of building and maintaining drying sheds. There however the sun is not as intense, nor the air nearly so dry, as it is here. Even there, the occurrence of an unusually hot summer, causes great loss. In our climate, some shelter would be commonly essential unless the peat be dug early in the spring, so as to lose the larger share of its water before the hot weather; or, as would be best of all, in the autumn late enough to escape the heat, but early enough to ensure such dryness as would prevent damage by frost. The peculiarities of climate must decide the time of excavating and the question of shelter.

The point in drying peat is to make it lose its water gradually and regularly, so that the inside of each block shall dry nearly as fast as the outside.

Some of the methods of hot-drying peat, will be subsequently noticed.

Summer or fall digging would be always advantageous on account of the swamps being then most free from water. In Bavaria, peat is dug mostly in July and the first half of August.

9.—Drainage.

When it is intended to raise peat fuel in the form of blocks, the bog should be drained no more rapidly than it is excavated. Peat, which is to be worth cutting in the spring, must be covered with water during the winter, else it is pulverized by the frost. So, too, it must be protected against drying away and losing its coherency in summer, by being kept sufficiently impregnated with water.

In case an extensive bog is to be drained to facilitate the cutting out of the peat for use as fuel, the canals that carry off the water from the parts which are excavating, should be so constructed, that on the approach of cold weather, the remaining peat may be flooded again to the usual height.

In most of the smaller swamps, systematic draining is unnecessary, the water drying away in summer enough to admit of easy working.

In some methods of preparing or condensing peat by machinery, it is best or even needful to drain and air-dry the peat, preliminary to working. By draining, the peat settles, especially on the borders of the ditches, several inches, or even feet, according to its nature and depth. It thus becomes capable of bearing teams and machinery, and its density is very considerably augmented.

10.—The Cutting of Peat.—a. Preparations.

In preparing to raise peat fuel from the bog, the surface material, which from the action of frost and sun has been pulverized to "muck," or which otherwise is full of roots and undecomposed matters, must be removed usually to the depth of 12 to 18 inches. It is only those portions of the peat which have never frozen nor become dry, and are free from coarse fibers of recent vegetation, that can be cut for fuel.

Peat fuel must be brought into the form of blocks or masses of such size and shape as to adapt them to use in our common stoves and furnaces. Commonly, the peat is of such consistence in its native bed, that it may be cut out with a spade or appropriate tool into blocks having more or less coherence. Sometimes it is needful to take away the surplus water from the bog, and allow the peat to settle and drain a while before it can be cut to advantage.

When a bog is to be opened, a deep ditch is run from an outlet or lowest point a short distance into the peat bed, and the working goes on from the banks of this ditch. It is important that system be followed in raising the peat, or there will be great waste of fuel and of labor.

If, as often happens, the peat is so soft in the wet season as to break on the vertical walls of a ditch and fill it, at the same time dislocating the mass and spoiling it for cutting, it is best to carry down the ditch in terraces, making it wide above and narrow at the bottom.

b. Cutting by hand.

The simplest mode of procedure, consists in laying off a "field" or plot of, say 20 feet square, and making vertical cuts with a sharp spade three or four inches deep from end to end in parallel lines, as far apart as it is proposed to make the breadth of the peats or sods, usually four to five inches. Then, the field is cut in a similar manner in lines at right angles to the first, and at a distance that shall be the length of the peats, say 18 to 20 inches. Finally, the workman lifts the peats by horizontal thrusts of his spade, made at a depth of three inches. The sods as lifted, are placed on a light barrow or upon a board or rack, and are carried off to a drying ground, near at hand, where they are laid down flatwise to drain and dry. In Ireland, it is the custom, after the peats have lain thus for a fortnight or so, to "foot" them, i. e. to place them on end close together; after further drying the "footing" is succeeded by "clamping," which is building the sods up into stacks of about twelve to fifteen feet long, four feet wide at bottom, narrowing to one foot at top, with a height of four to five feet. The outer turfs are inclined so as to shed the rain. The peat often remains in these clamps on the bog until wanted for use, though in rainy seasons the loss by crumbling is considerable.



Other modes of lifting peat, require tools of particular construction.... In Germany it is common to excavate by vertical thrusts of the tool, the cutting part of which is represented above, fig. 2. This tool is pressed down into the peat to a depth corresponding to the thickness of the required block: its three edges cut as many sides of the block, and the bottom is then broken or torn out by a prying motion.

In other cases, this or a similar tool is forced down by help of the foot as deeply into the peat as possible by a workman standing above, while a second man in the ditch cuts out the blocks of proper thickness by means of a sharp spade thrust horizontally. When the peats are taken out to the depth of the first vertical cutting, the knife is used again from above, and the process is thus continued as before, until the bottom of the peat or the desired depth is reached.

In Ireland, is employed the "slane," a common form of which is shown in fig. 3, it being a long, narrow and sharp spade, 20 inches by six, with a wing at right angles to the blade.



The peats are cut by one thrust of this instrument which is worked by the arms alone. After a vertical cut is made by a spade, in a line at right angles to a bank of peat, the slane cuts the bottom and other side of the block; while at the end the latter is simply lifted or broken away.

Peat is most easily cut in a vertical direction, but when, as often happens, it is made up of layers, the sods are likely to break apart where these join. Horizontal cutting is therefore best for stratified peat.

System employed in East Friesland.—In raising peat, great waste both of labor and of fuel may easily occur as the result of random and unsystematic methods of working. For this reason, the mode of cutting peat, followed in the extensive moors of East Friesland, is worthy of particular description. There, the business is pursued systematically on a plan, which, it is claimed, long experience[17] has developed to such perfection that the utmost economy of time and labor is attained. The cost of producing marketable peat in East Friesland in 1860, was one silver groschen=about 2-1/2 cents, per hundred weight; while at that time, in Bavaria, the hundred weight cost three times as much when fit for market; and this, notwithstanding living and labor are much cheaper in the latter country.

The method to be described, presupposes that the workmen are not hindered by water, which, in most cases, can be easily removed from the high-moors of the region. The peat is worked in long stretches of 10 feet in width, and 100 to 1000 paces in length: each stretch or plot is excavated at once to a considerable depth and to its full width. Each successive year the excavation is widened by 10 feet, its length remaining the same. Sometimes, unusual demand leads to more rapid working; but the width of 10 feet is adhered to for each cutting, and, on account of the labor of carrying the peats, it is preferred to extend the length rather than the width.

Assuming that the peat bed has been opened by a previous cutting, to the depth of 5-1/2 feet, and the surface muck and light peat, 1-1/2 feet thick, have been thrown into the excavation of the year before—a new plot is worked by five men as follows.

One man, the "Bunker," removes from the surface, about two inches of peat, disintegrated by the winter's frost, throwing it into last year's ditch.

Following him, come two "Diggers," of whom one stands on the surface of the peat, and with a heavy, long handled tool, cuts out the sides and end of the blocks, which are about seventeen by five inches; while the other stands in the ditch, and by horizontal thrusts of a light, sharp spade, removes the sods, each of five and a half inches thickness, and places them on a small board near by. Each block of peat has the dimensions of one fourth of a cubic foot, and weighs about 13 pounds. Two good workmen will raise 25 such peats, or 6-1/4 cubic feet, per minute.

A fourth man, the "Loader," puts the sods upon a wheel-barrow, always two rows of six each, one upon the other, and—

A fifth, the "Wheeler," removes the load to the drying ground, and with some help from the Bunker, disposes them flatwise in rows of 16 sods wide, which run at right angles to the ditch, and, beginning at a little more than 10 feet from the latter, extend 50 feet.

The space of 10 feet between the plot that is excavating, and the drying ground, is, at the same time, cleared of the useless surface muck by the Bunker, in preparation for the next year's work.

With moderate activity, the five men will lift and lay out 12,000 sods (3000 cubic feet,) daily, and it is not uncommon that five first-rate hands get out 16,800 peats (4200 cubic feet,) in this time.

A gang of five men, working as described, suffices for cutting out a bed of four feet of solid peat. When the excavation is to be made deeper, a sixth man, the "Hanker," is needful for economical work; and with his help the cutting may be extended down to nine and a half feet; i. e. through eight feet of solid peat. The cutting is carried down at first, four feet as before, but the peats are carried 50 feet further, in order to leave room for those to be subsequently lifted. The "Hanker" aids here, with a second wheel-barrow. In taking out the lower peat, the "Hanker" stands on the bottom of the first excavation, receives the blocks from the Diggers, on a broad wooden shovel, and hands them up to the Loader; while the Wheeler, having only the usual distance to carry them, lays them out in the drying rows without difficulty.

After a little drying in the rows, the peats are gradually built up into narrow piles, like a brick wall of one and a half bricks thickness. These piles are usually raised by women. They are made in the spaces between the rows, and are laid up one course at a time, so that each block may dry considerably, before it is covered by another. A woman can lay up 12,000 peats daily—the number lifted by 5 men—and as it requires about a month of good weather to give each course time (two days) to dry, she is able to pile for 30 gangs of workmen. If the weather be very favorable, the peats may be stacked or put into sheds, in a few days after the piling is finished. Stacking is usually practised. The stacks are carefully laid up in cylindrical form, and contain 200 to 500 cubic feet. When the stacks are properly built, the peat suffers but little from the weather.

According to Schroeder, from whose account (Dingler's Polytechnisches Journal, Bd. 156, S. 128) the above statements are derived, the peats excavated under his direction, in drying thoroughly, shrank to about one-fourth of their original bulk (became 12 inches x 3 inches x 3 inches,) and to one-seventh or one-eighth of their original weight.

c. Machines for Cutting Peat.

In North Prussia, the Peat Cutting Machine of Brosowsky, see fig. 4, is extensively employed. It consists of a cutter, made like the four sides of a box, but with oblique edges, a, which by its own weight, and by means of a crank and rack-work, operated by men, is forced down into the peat to a depth that may reach 20 feet. It can cut only at the edge of a ditch or excavation, and when it has penetrated sufficiently, a spade like blade, d, is driven under the cutter by means of levers c, and thus a mass is loosened, having a vertical length of 10 feet or more, and whose other dimensions are about 24 x 28 inches. This is lifted by reversing the crank motion, and is then cut up by the spade into blocks of 14 inches x 6 inches x 5 inches. Each parallelopipedon of peat, cut to a depth of 10 feet, makes 144 sods, and this number can be cut in less than 10 minutes. Four hands will cut and lay out to dry, 12,000 to 14,000 peats daily, or 3100 cubic feet. One great advantage of this machine consists in the circumstance that it can be used to raise peat from below the surface of water, rendering drainage in many cases unnecessary. Independently of this, it appears to be highly labor saving, since 1300 machines were put to use in Mecklenburg and Pomerania in about 5 years from its introduction. The Mecklenburg moors are now traversed by canals, cut by this machine, which are used for the transportation of the peat to market.[18]



Lepreux in Paris, has invented a similar but more complicated machine, which is said to be very effective in its operation. According to Herve Mangon, this machine, when worked by two men, raises and cuts 40,000 peats daily, of which seven make one cubic foot, equal to 5600 cubic feet. The saving in expense by using this machine[19] is said to be 70 per cent., when the peat to be raised is under water.

11.—The Dredging of Peat.

When peat exists, not as a coherent more or less fibrous mass, but as a paste or mud, saturated with water, it cannot be raised and formed by the methods above described.

In such cases the peat is dredged from the bottom of the bog by means of an iron scoop, like a pail with sharp upper edges, which is fastened to a long handle. The bottom is made of coarse sacking, so that the water may run off. Sometimes, a stout ring of iron with a bag attached, is employed in the same way. The fine peat is emptied from the dredge upon the ground, where it remains, until the water has been absorbed or has evaporated, so far as to leave the mass somewhat firm and plastic. In the mean time, a drying bed is prepared by smoothing, and, if needful, stamping a sufficient space of ground, and enclosing it in boards 14 inches wide, set on edge. Into this bed the partially dried peat is thrown, and, as it cracks on the surface by drying, it is compressed by blows with a heavy mallet or flail, or by treading it with flat boards, attached to the feet, somewhat like snow shoes. By this treatment the mass is reduced to a continuous sheet of less than one-half its first thickness, and becomes so firm, that a man's step gives little impression in it. The boards are now removed, and it is cut into blocks by means of a very thin, sharp spade. Every other block being lifted out and placed crosswise upon those remaining, air is admitted to the whole and the drying goes on rapidly. This kind of peat is usually of excellent quality. In North Germany it is called "Baggertorf," i. e. mud-peat.

Peat is sometimes dredged by machinery, as will be noticed hereafter.

12.—The Moulding of Peat.

When black, earthy or pitchy peat cannot be cut, and is not so saturated with water as to make a mud; it is, after raking or picking out roots, etc., often worked into a paste by the hands or feet, with addition of water, until it can be formed into blocks which, by slow drying, acquire great firmness. In Ireland this product is termed "hand-peat." In Germany it is called "Formtorf," i. e. moulded peat, or "Backtorf," i. e. baked peat.

The shaping is sometimes accomplished by plastering the soft mass into wooden moulds, as in making bricks.

13.—Preparation of Peat Fuel by Machinery, etc.

Within the last 15 years, numerous inventions have been made with a view to improving the quality of peat fuel, as well as to expedite its production. These inventions are directed to the following points, viz.: 1. Condensation of the peat, so as bring more fuel into a given space, thus making it capable of giving out an intenser heat; at the same time increasing its hardness and toughness, and rendering it easier and more economical of transportation. 2. Drying by artificial heat or reducing the amount of water from 20 or 25 per cent. to half that quantity or less. This exalts the heating power in no inconsiderable degree. 3. Charring. Peat-charcoal is as much better than peat, for use where intense heat is required, as wood charcoal is better than wood. 4. Purifying from useless matters. Separation of earthy admixtures which are incombustible and hinder draught.

A.—Condensation by Pressure.

Pressing Wet Peat.—The condensation of peat was first attempted by subjecting the fresh, wet material, to severe pressure. As long ago as the year 1821, Pernitzsch, in Saxony, prepared peat by this method, and shortly afterwards Lord Willoughby d'Eresby, in Scotland, and others, adopted the same principle. Simple pressure will, indeed, bring fresh peat at once into much smaller bulk; but, if the peat be fibrous and light, and for this reason require condensation, it is also elastic, and, when the pressure is relieved, it acquires again much of its original volume.

Furthermore, although pressure will squeeze out much water from a saturated well-ripened peat, the complete drying of the pressed blocks usually requires as much or more time than that of the unpressed material, on account of the closeness of texture of the surface produced by the pressure.

The advantages of subjecting fresh peat to pressure in the ordinary presses, it is found, are more than offset by the expense of the operation, and it is therefore unnecessary to give the subject further attention.

Fresh peat appears however to have been advantageously pressed by other mechanical means. Two methods require notice.

Mannhardt's Method, invented about the year 1858, has been practically applied on the large scale at Schleissheim, Bavaria. Mannhardt's machine consists of two colossal iron rolls, each of 15 feet diameter, and 6-1/2 feet length, geared into each other so as to revolve horizontally in opposite directions and with equal velocity. These rolls are hollow, their circumference consists of stout iron plate perforated with numerous small holes, and is supported by iron bars which connect the ends of the roll, having intervals between them of about one inch. Each roll is covered by an endless band of hair cloth, stretched over and kept in place by rollers. The rolls are operated by a steam engine of 12 horse power. The fresh peat is thrown into a hopper, and passing between the rolls, loses a considerable share of its water, issuing as a broad continuous sheet, which is divided into blocks by an arrangement presently to be described. The cloth, covering the rolls, must have great strength, sufficient porosity to allow water to pass it freely, and such closeness of texture as to retain the fine particles of peat. Many trials have led to the use of a fabric, specially made for the purpose, of goat's hair. The cloth for each pair of rolls, costs $160.

The peat at Schleissheim is about 5 feet in depth, and consists of a dark-brown mud or paste, free from stones and sticks, and penetrated only by fine fibers. The peat is thrown up on the edge of a ditch, and after draining, is moved on a tram-way to the machine. It is there thrown upon a chain of buckets, which deliver it at the hopper above the rolls. The rolls revolve once in 7-1/3 minutes and at each revolution turn out a sheet of peat, which cuts into 528 blocks. Each block has, when moist, a length of about 12 inches, by 5 inches of width and 1-1/4 inches of thickness, and weighs on the average 1-1/2 lbs. The water that is pressed out of the peat, falls within the rolls and is conducted away; it is but slightly turbid from suspended particles. The band of pressed peat is divided in one direction as it is formed, by narrow slats which are secured horizontally to the press-cloth, at about 5 inches distance from each other. The further division of the peat is accomplished by a series of six circular saws, under which the peat is carried as it is released from the rolls, by a system of endless cords strung over rollers. These cords run parallel until the peat passes the saws; thenceforth they radiate, so that the peat-blocks are separated somewhat from each other. They are carried on until they reach a roll, over which they are delivered upon drying lattices. The latter move regularly under the roll; the peats arrange themselves upon them edgewise, one leaning against the other, so as to admit of free circulation of air. The lattices are loaded upon cars, and moved on a tram-way to the drying ground, where they are set up in frames.

The peat-cake separates well from the press-cloths; but the pores of the latter become somewhat choked by fine particles that penetrate them. They are therefore washed at each revolution by passing before a pipe from which issue, against them, a number of jets of water under high pressure. The blocks, after leaving the machine, are soft, and require 5 or 6 days to become air-dry. When dry they are dense and of good quality, but not better than the same raw material yields by simple moulding. The capacity of the rolls, which easily turn out 100,000 peats in 24 hours, greatly exceeds at present that of the drying arrangements, and for this reason the works are not, as yet, remunerative. The rolls are, in reality, a simple forming machine. The pressure they exert on the peat, is but inconsiderable, owing to its soft pasty character; and since the pair of rolls costs $8000 and can only be worked 3 to 4 months, this method must be regarded rather as an ingenious and instructive essay in the art of making peat-fuel, than as a practical success. The persevering efforts of the inventor may yet overcome all difficulties and prove the complete efficacy of the method. It is especially important, that blocks of greater thickness should be produced, since those now made, pack together too closely in the fire.

Neustadt Method.—At Neustadt, in Hanover, a loose-textured fibrous peat was prepared for metallurgical use in 1860, by passing through iron rolls of ordinary construction. The peat was thereby reduced two-thirds in bulk, burned more regularly, gave a coherent coal, and withstood carriage better. The peat was, however, first cut into sods of regular size, and these were fed into the rollers by boys.

b. Pressing Air-dried Peat.

Some kinds of peat, when in the air-dry and pulverized state, yield by great pressure very firm, excellent, and economical fuel.

Lithuanian Process.—In Lithuania, according to Leo,[20] the following method is extensively adopted. The bog is drained, the surface moss or grass-turf and roots are removed, and then the peat is broken up by a simple spade-plow, in furrows 2 inches wide and 8 or 10 inches deep. The broken peat is repeatedly traversed with wooden harrows, and is thus pulverized and dried. When suitably dry, it is carried to a magazine, where it is rammed into moulds by a simple stamp of two hundred pounds weight. The broken peat is reduced to two-fifths its first bulk, and the blocks thus formed are so hard, as to admit of cutting with a saw or ax without fracture. They require no further drying, are of a deep-brown color, with lustrous surfaces, and their preparation may go on in winter with the stock of broken peat, which is accumulated in the favorable weather of summer. In this manufacture there is no waste of material.

The peat is dry enough for pressing when, after forming in the hands to a ball, it will not firmly retain this shape, but on being let fall to the ground, breaks to powder. The entire cost of preparing 1000 peats for use, or market, was 2 Thalers, or $1.40. Thirty peats, or "stones" as they are called from their hardness, have the bulk of two cubic feet, and weigh 160 lbs. The cost of preparing a hundred weight, was therefore, (in 1859,) four Silver-groschen, or about 10 cents.

The stamp is of simple construction, somewhat like a pile driver, the mould and face of the ram being made of cast iron. The above process is not applicable to fibrous peat.

c. Pressing Hot-dried Peat.

The two methods to be next described, are similar to the last mentioned, save that the peat is hot-pressed.

Gwynne's Method.—In 1853, Gwynne of London, patented machinery and a method for condensing peat for fuel. His process consisted, first, in rapidly drying and pulverizing the fresh peat by a centrifugal machine, or by passing between rollers, and subsequent exposure to heat in revolving cylinders; and, second, in compressing the dry peat-powder in a powerful press at a high temperature, about 180 deg. F. By this heat it is claimed, that the peat is not only thoroughly dried, but is likewise partially decomposed; bituminous matters being developed, which cement the particles to a hard dense mass. Gwynne's machinery was expensive and complicated, and although an excellent fuel was produced, the process appears not to have been carried put on the large scale with pecuniary success.

A specimen of so-called "Peat coal" in the author's possession, made in Massachusetts some years ago, under Gwynne's patent, appears to consist of pulverized peat, prepared as above described; but contains an admixture of rosin. It must have been an excellent fuel, but could not at that time compete with coal in this country.

Exter's Method.[21]



In 1856, Exter, of Bavaria, carried into operation on an extensive scale, a plan of preparing peat-fuel in some respects not unlike the last mentioned method. Exter's works, belonging to the Bavarian Government, are on the Haspelmoor, situated between Augsburg and Munich. According to Ruehlmann, who examined them at the command of the Hanoverian Government in 1857, the method is as follows:—1. The bog is laid dry by drains and the surface is cleared of bushes, roots, and grass-turf, down to good peat. 2. The peat is broken up superficially to the depth of about one inch, by a gang of three plows, propelled by a portable steam engine. 3. The peat is further pulverized by a harrow, drawn by a yoke of oxen. 4. In two or three days after harrowing, the peat is turned by an implement like our cultivator, this process being repeated at suitable intervals. 5. The fine and air-dry peat is gathered together by scrapers, and loaded into wagons; then drawn by rope connected with the engine, to the press or magazine. 6. If needful, the peat, thus collected, is further pulverized by passing it through toothed rollers. 7. The fine peat is now introduced into a complicated drying oven, see figures 5 and 6. It falls through the opening T, and is moved by means of the spirals along the horizontal floors O, O, falling from one to another until it emerges at Q. The floors, O, O, are made by wide and thin iron chambers, through which passes waste steam from an engine. The oven is heated further by hot air, which circulates through the canals K, K. The peat occupies about one hour in its passage through the oven and falls from Q, into the press, having a temperature of from 120 deg. to 140 deg.Fahrenheit. The press employed at Staltach is essentially the same as that now used at the Kolbermoor, and figured on p. 125. It is a powerful eccentric of simple construction, and turns out continuously 40 finished peats per minute. These occupy about one-fourth the space of the peat before pressing, the cubic foot weighing about 72 lbs. The peats are 7 inches long, 3 inches wide, and one half to three quarters of an inch thick, each weighing three quarters of a pound. Three presses furnish annually 180,000 cwt. of condensed peat, which is used exclusively for firing locomotives. Its specific gravity is 1.14, and its quality as fuel is excellent. Ruehlmann estimated its cost, at Haspelmoor in 1857, at 8-1/2 Kreuzers, or a little more than 6 cents per cwt., and calculated that by adopting certain obvious improvements, and substituting steam power for the labor of men and cattle, the cost might be reduced to 6-1/2 Kreuzers, or a little more than 4 cents per cwt.

Exter's method has been adopted with some modifications at Kolbermoor, near Munich, in Bavaria, at Miskolz, in Hungary, and also at the Neustadt Smelting Works, in Hanover. At the latter place, however, it appears to have been abandoned for the reasons that it could be applied only to the better kinds of peat; and the expense was there so great, that the finished article could not compete with other fuel in the Hanoverian markets.

Details of the mechanical arrangements at present employed on the Kolbermoor, are as follows: After the bog is drained, and the surface cleared of dwarf pines, etc., and suitably leveled, the peat is plowed by steam. This is accomplished in a way which the annexed cut serves to illustrate. The plot to be plowed, is traversed through the middle by the railway x, y. A locomotive a, sets in motion an endless wire-rope, which moves upon large horizontal pulleys o, o, stationed at either border of the land. Four gang plows b, b, are attached to the rope, and as the latter is set in motion, they break up the strip of peat they pass over, completely. The locomotive and the pulleys are then moved back, and the process is repeated until the whole field has been plowed. The plows are square frames, carrying six to eight shares and as many coulters.



The press employed at Kolbermoor, is shown in figs. 8 and 9. The hot peat falls into the hopper, b, c. The plunger d, worked in the cavity e, by an eccentric, allows the latter to fill with peat as it is withdrawn, and by its advance compresses it into a block. The blocks m, once formed, by their friction in the channel e, oppose enough resistance to the peat to effect its compression. In order to regulate this resistance according to the varying quality of the peat, the piece of metal g, which hangs on a pivot at o, is depressed or raised, by the screw i, so as to contract or enlarge the channel. At each stroke of the plunger a block is formed, and when the channel e is once filled, the peats fall continuously from its extremity. Their dimensions are 7 inches long, 3-1/2 wide, and 1-1/2 thick.



Several presses are worked by the same engine at the Kolbermoor, each of which turns out daily 200 to 300 cwt. of peats, which, in 1863, were sold at 24 Kreuzers (16 cents), per cwt.



C. Hodgson has patented in Great Britain a compressing-ram similar to Exter's, and works were put up at Derrylea, in Ireland, some years ago, in which Exter's process of manufacturing peat fuel appears to have been adopted.

Elsberg's Process.

Dr. Louis Elsberg, of New York City, has invented a modification of Exter's method, which appears to be of great importance. His experimental machine, which is in operation near Belleville, N. J., consists of a cylindrical pug-mill, in which the peat, air-dried as in Exter's method, is further broken, and at the same time is subjected to a current of steam admitted through a pipe and jacket surrounding the cylinder. The steamed peat is then condensed by a pair of presses similar to that just described, which are fed directly from the mill. In this way the complicated drying oven of Exter is dispensed with. Elsberg & Co. are still engaged in perfecting their arrangements. Some samples of their making are of very excellent quality, having a density of 1.2 to 1.3.

The pressing of air-dry peat only succeeds when it is made warm, and is, at the same time, moist. In Exter's original process the peat is considerably dried in the ovens, but on leaving them, is so moist as to bedew the hand that is immersed in it. It is, in fact, steamed by the vaporization of its own water. In Elsberg's process, the air-dry peat is not further desiccated, but is made moist and warm by the admission of hot steam. The latter method is the more ready and doubtless the more economical of the two. Whether the former gives a dryer product or not, the author cannot decide. Elsberg's peat occurs in cylindrical cakes 2 inches broad, and one inch in thickness. The cakes are somewhat cracked upon the edges, as if by contraction, in drying. When wet, the surface of the cakes swells up, and exfoliates as far as the water has penetrated. In the fire, a similar breaking away of the surface takes place, and when coked, the coal is but moderately coherent.

The reasons why steamed peat admits of solidification by pressure, are simply that the air, ordinarily adhering to the fibres and particles, is removed, and the fibres themselves become softened and more plastic, so that pressure brings them into intimate contact. The idea that the heat develops bituminous matters, or fuses the resins which exist in peat, and that these cement the particles, does not harmonize with the fact that the peat, thus condensed, flakes to pieces by a short immersion in water.

The great advantage of Exter's and Elsberg's method consists in avoiding what most of the others require, viz.: the expensive transportation and handling of fresh peat, which contains 80 to 90 per cent. of water, and the rapid removal of this excess of water before the manufacture. In the other methods the surplus water must be slowly removed during or after condensation.

Again, enough peat may be air-dried and stored during summer weather, to supply a machine with work during the whole year.

Its disadvantages are, that it requires a large outlay of capital and great expenditure of mechanical force. Its product is, moreover, not adapted for coking.

B.—Condensation without Pressure.

The methods of condensing peat, that remain to be described, are based upon radically different principles from those already noticed. In these, little or no pressure is employed in the operations; but advantage is taken of the important fact that when wet or moist peat is ground, cut or in any way reduced to a pulpy or pasty consistence, with destruction of the elastic fibres, it will, on drying, shrink together to a coherent mass, that may acquire a density and toughness much greater than it is possible to obtain by any amount of mere pressure.

The various processes that remain to notice are essentially reducible to two types, of which the French method, invented by Challeton, and the German, invented it appears by Weber, are the original representatives. The former method is only applicable to earthy, well-decomposed peat, containing little fibre. The latter was originally applied to fibrous moss-peat, but has since been adapted to all kinds. Other inventors, English, German, and American, have modified these methods in their details, or in the construction of the requisite machinery, rendering them more perfect in their execution and perhaps more profitable in their results; but, as regards the essential principles of production, or the quality of product, no advance appears to have been made beyond the original inventors.

a. Condensation of Earthy Peat.

Challeton's Method consists essentially in destroying the fibres, and reducing the peat by cutting and grinding with water to a pulp; then slowly removing the liquid, until the peat dries away to a hard coherent mass. It provides also for the purification of the peat from earthy matters. It is, in many respects, an imitation of the old Dutch and Irish mode of making "hand peat" (Baggertorf), and is very like the paper manufacture in its operations. Challeton's Works, situated near Paris, at Mennecy, near Montanges, were visited in 1856 by a Commission of the Agricultural Society of Holstein, consisting of Drs. Meyn and Luetkens, and also by Dr. Ruehlmann, in the interest of the Hanoverian Government. From their account[22] the following statements are derived.

The peat at Mennecy comes from the decay of grasses, is black, well decomposed, and occasionally intermingled with shells and sand. The moor is traversed by canals, which serve for the transport of the excavated peat in boats. The peat, when brought to the manufactory, is emptied into a cistern, which, by communicating with the adjacent canal, maintains a constant level of water. From this cistern the peat is carried up by a chain of buckets and emptied into a hopper, where it is caught by toothed cylinders in rapid revolution, and cut or torn to pieces. Thence it passes into a chamber where the fine parts are separated from unbroken roots and fibres by revolving brushes, which force the former through small holes in the walls of the chamber, while the latter are swept out through a larger passage. The pulverized peat finally falls into a cistern, in which it is agitated by revolving arms. A stream of water constantly enters this vessel from beneath, while a chain of buckets as rapidly carries off the peat pulp. All sand, shells, and other heavy matters, remain at the bottom of this cistern.

The peat pulp, thus purified, flows through wooden troughs into a series of basins, in which the peat is formed and dried. These basins are made upon the ground by putting up a square frame (of boards on edge,) about one foot deep, and placing at the bottom old matting or a layer of flags or reeds. Each basin is about a rod square, and 800 of them are employed. They are filled with the peat pulp to the top. In a few days the water either filters away into the ground, or evaporates, so that a soft stratum of peat, about 3 inches in thickness, remains. Before it begins to crack from drying, it is divided into blocks, by pressing into it a light trellis-like framework, having thin partitions that serve to indent the peat in lines corresponding to the intended divisions. On further drying, the mass separates into blocks at the lines thus impressed, and in a few days, they are ready to remove and arrange for further desiccation.

The finished peats from Challeton's works, as well as those made by the same method near Neuchatel, Switzerland, by the Messrs. Roy, were of excellent quality, and in the opinion of the Commission from Holstein, the method is admirably adapted for the purification and concentration of the heavy kinds of peat.

In Holstein, a French company constructed, and in 1857 worked successfully a portable machine for preparing peat on this plan, but were shortly restrained by legal proceedings. Of their later operations we have no information.

No data are at hand regarding the cost of producing fuel by Challeton's machinery. It is believed, however, that his own works were unremunerative, and several manufactories on his pattern, erected in Germany, have likewise proved unprofitable. The principle is, however, a good one, though his machinery is only applicable to earthy or pitchy, and not to very fibrous peat. It has been elsewhere applied with satisfactory results.

Simplified machinery for applying Challeton's method is in operation 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.



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.



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.



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.



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.



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.



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.



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.



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.



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.



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.



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.



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.