Brass guns and their charges.
The block-houses erected by the Hudson’s Bay Company, as depôts and forts in connection with the fur trade, usually have guns mounted in them. Brass field guns and howitzers are also at times to be met with at the border stations of wild countries, and it may, therefore, be well to know the charges and ranges of the ordinary kinds, which are as follows:
BRASS FIELD GUNS.
BRASS HOWITZERS.
Cartridges and wads for cannon.
Cartridges for either brass or iron guns are best made of some woollen material; trade serge or old blanketing answers very well for the purpose. Bags should be made a little less than the bore, and into these the charge of powder is to be poured. A piece of woollen thread, double worsted, or twine should now be used to close the end of the bag, after which it is to be passed two or three times round the bag, giving it at the same time a compact cylindrical form by rolling on a board or table under the hand. Passing the thread through the substance of the cartridge aids much in keeping its form and facilitates loading. A cartridge needle should be used to perform this operation. This needle can be easily made from a piece of stout copper or brass wire. Flatten out one end, drill or punch a hole in it to form the eye, and file the other end sharp for a point. Fourteen inches is a convenient length for a cartridge needle. It is said that a sailor’s wife enabled a British vessel to continue a long and desperate fight by pillaging the officers’ quarters of all the stockings she could find, and handing them up to be filled for cartridges. The intestines of animals, according to their size, would make as good cartridge cases as could be desired. Wads may be made of picked oakum twisted in a flat spiral to the proper size of the bore, when they are made to retain their shape by being secured here and there with fine twine passed through with the needle. In the absence of oakum, wooden wads may be made by first spokeshaving a stout pole to the size of the bore, and then sawing it up into convenient lengths.
Guns to unspike and repair.
Old guns which have been laid by will not uncommonly be found spiked, by having a common nail driven into the vent. If efficient tools are at hand this may be drilled out, if not, put a charge of powder in the gun, bore a gimlet hole in one of your wooden wads, through which pass a loosely-twisted string well impregnated with dissolved gunpowder, and afterwards dried. Cut the end of your prepared string just at the muzzle of the gun, light it, and get out of the way, when the explosion, which soon takes place, will not unfrequently expel the spike. A gun which has had its trunnions knocked off, with a view to rendering it useless, may be made nearly as effective as ever by cutting with the axeor adze a bed for it in a stout piece of log, of such a form that the cascabel of the gun and the breech end are rather more than half buried in solid wood. The log may now be trimmed off to convenient dimensions, and all made secure by a lashing of wet raw hide rope, which rests in a broad shallow notch cut in the log to receive it. The gun and its bed are thus, as the rope dries, held together by a material little less rigid than iron.
Priming cups, to make.
The bed log and gun may now be mounted by placing a very strong round bar of hard tough wood across the slide or carriage immediately below where the trunnions would have rested. This receives a deep semicircular notch, cut to exactly correspond with it on the under side of the bed log. The gun can now be elevated and depressed in the usual manner by placing wedges under the log. The common mode of priming a gun from a flask or horn, when there are no percussion or friction tubes to be obtained, is, to say the least of it, inconvenient and dangerous. It is far better to keep on hand a few priming cups. These are made as follows: From the joints of a bamboo cut a number of little cups, the bottoms being formed by the knots of the cane; in the centre of the bottom bore a hole, with a gimlet or red hot wire, large enough to admit a piece of marsh reed, hollow cane, weed stalk, or quill, about 3in. long, and small enough in diameter to pass down into the vent of the gun easily; stop the small end with a bit of melted sealing-wax; secure the large end in the cup by the same agency.
The cup becomes now a sort of funnel, through which common fine sporting powder should be poured until both tube and cup are full, when a piece of oiled paper is strained over the top of the cup like the head of a drum, and is tied fast with twine. When the gun is to be fired, the cartridge is pierced in the usual way with the priming wire. The tube of the priming cup is now to be inserted at the mouth of the vent, and pressed down until the bottom of the cup rests on the metal of the gun, when on the port fire or linstock being applied, the paper lid is instantly burned through, and the gun discharged. In windy weather, heavy tropical rains, or at night, these cups are extremely useful.
Makeshift firearms.
A cannon, of very tolerable efficiency for close quarters, and slug or bullet charges, may be made by boring a hole partly through a piece of tough strong log, with a pump auger; bore a vent with a gimlet, put on one or two hoops or rings of iron or raw hide, and the gun is ready for use. We have seen several of these, which were effectually used during the rebellion in Canada.
In 1838, at the siege of Herat, Mahomed Shah brought up a quantity of metal on the backs of camels, and had a heavy bronze gun cast, and completely finished before the town; and when the siege was raised the king had his gun sawn to pieces and taken to Teheran. Shah Abbas, of Ispahan, had a heavy piece of artillery, but said it would delay his march, and he would much rather carry metal on camels and cast artillery before the enemy’s town.
During the Indian mutiny, the rebels pulled down the telegraph-posts which had iron tube sockets fitted to them in order to keep off the white ants. These sockets were taken off, and vents drilled in them. They were then loaded with powder, and charges of slugs made from doubled up and hammered pieces of the telegraph wire. We have seen a piece of common iron gas-pipe, a piece of wood, and a few bits of sheet copper, converted into a very formidable matchlock pistol.
In our Australian boat voyage we had a small 1lb. swivel carronade. We jammed a pole about 6ft. long into the fork of the swivel, and had we met any of the Malay trepang fishers, who go in companies of a hundred or more, we should have made the swivel-bolt fast to the bowsprit just outside the stem of our boat, and, letting the trail rest on the mast thwart, have defended ourselves with heavy charges of musket bullets. Of course the fishers might have been friendly, or, if not, the knowledge that we had a gun would have made them so, and we should not in any case have been the aggressors.
The Zemboureks, or dromedary artillery.
Light guns mounted on dromedaries or camels are valuable for the defence of caravans, &c. The Afghans first used these in an emergency against the Persians. A number of pivoted arquebuses were mounted on the saddles of dromedaries, which were taught to kneel while the pieces were firedfrom their backs. The Persians, profiting by the lessons of their defeat, also organised a similar force, the guns weighing not more than 75lb. The saddle was originally constructed of two-forked branches connected by wooden bars, and if the gun was slightly overloaded the recoil would injure the fittings, and disturb the animal; but subsequently the saddle was much improved, and wheels were added, so that it might be taken from the animal’s back and used as a field gun. It will be seen that the staff of the bannerol carries a little tent, and this covers the ammunition bags. A skin of water hangs under the belly of the camel. The Persians have sought out with eagerness and perseverance the best form of artillery to be carried on the backs of animals; and, as it seems that dromedaries have been successfully imported into America and Australia, it may be of advantage to know that they are capable of being utilised in this way. Other animals, perhaps oxen, might be trained to carry smaller guns.
dromedary artillery
Very efficient common case shot can be made by filling empty preserved-meat tins with rifle or pistol balls. A bag of cooper’s iron hoop rivets is a very favourite charge among the South-Sea whalers. Round shot can be made as directed under the head “Lead, and its Uses.”
Grenades and rocket arrows.
Extempore grenades can be made from empty soda-water bottles or old ink jars. On one occasion we made a number from the latter vessels by filling them with a mixture of buck shot and strong sporting powder; stoppers of wood were then fitted by notching the upper ends, and fasteningthem down with wire, like the corks of champagne bottles, a gimlet hole was then bored in each, and a few inches of quick match put in. When the fuse has been lighted, these vessels are either hurled from the hand or fired from large powerful cross-bows, when they, by exploding in full flight or on the ground, cause no trifling confusion among an undisciplined enemy, a pack of wolves, or a sounder of hog in a cactus brake.
An unarmed merchantman was chased by a pirate galley; she hove to, and pretended to surrender, but two men stood at the gangway with a cask of powder. As soon as the long low open boat came alongside they threw it into her, and the cook, running out of the galley, threw a shovelful of hot coals after it. The ship forged ahead before the smoke had cleared away, and escaped, leaving the desperadoes to their fate.
Large arrows tipped with strong paper cases, such as are made for rockets, only choked at the bottom, become most formidable projectiles. The cases are partly filled with powder, a wad, with a hole in it, is rammed down on the charge, a quill is put in the hole, about thirty buck shot are deposited round the quill, which is filled with meal powder. The case and quill head are then capped with paper which has been soaked in dissolved gunpowder or nitre. Arrows thus made are to be fired from powerful hand-bows, after the match has been lighted. In the true rocket arrow the touchpaper is ignited just before the arrow is fixed in the bow, and it is shot just before the fire reaches the composition; the combustion then aids the flight rather than retards it. The head is strongly barbed, so that it may not easily be drawn from thatched roofs, &c.; the Chinese and Indian tribes often use these.
a gunpowder press
Gunpowder, to make.
It sometimes happens that the hunter or explorer has, like many members of the Algerian, Tartar, and Mongolian tribes, to turn gunpowder manufacturer. To make gunpowder three ingredients are requisite: viz., saltpetre (nitrate of potash), sulphur, and charcoal. The two former ingredients should form a part of the equipment of an expedition (see “Farrier’s Stores,”p. 84). Still, where such stores are not carried, sulphur and saltpetre are usually to be obtained, more or lesspure, from the natives of all but the most unfrequented and isolated countries. The saltpetre will require recrystallisation, which is carried out as follows: Take equal quantities, by measure, of the saltpetre and boiling water, stir them well about with a stick until all the lumps are thoroughly dissolved; strain the resulting fluid through a coarse cloth in order to get rid of sticks, chips, and stones, and set it aside to crystallise; when the process is complete drain the water from the crystals, set them to dry on a skin or a cloth. The sulphur, if in lumps as imported, will require purification by melting. This operation must be conducted over a very slow fire, and immediately the mass becomes liquid in the pot it should be put to stand for a few minutes in hot wood ashes in order that impurities may settle to the bottom. The neck of the vessel may then be held fast in a twisted stick, and the contents poured dexterously out into a convenient mould until the sediment at the bottom, which is useless, is left. Flour of sulphur will not require this treatment. The charcoal (see “Charcoal Burning,”p. 267) should, for gunpowder making, be prepared from some light, clean-grained wood. In this country willow, withy, alder, hazel, linden, &c., are held in high esteem for the purpose; but in wild countries the nearest approach to these within reach should be obtained. The three ingredients must be first separately ground, either in a native quern or stone handmill, between two conveniently-formed stones, or in an extempore pestle and mortar, until reduced to perfect powder, quite free from lumps or grit. The three powders are to be now weighed out carefully in the following proportions: One part sulphur, one part charcoal, and six parts saltpetre. Mix these on a skin pegged out on the ground, and rub the mixture together with the palms of the hands until most intimately and thoroughly blended; then, with an empty percussion-cap box or drinking cup, measure your mixture, and for every ten cups or boxes of powder put down a stone or make a mark, and for every mark put aside a cup full of warm water, so that you have just one-tenth of fluid. This you sprinkle with a bunch of feathers or grass, a little at a time, on the powders, until, by constant and persistent working and kneading, a smooth homogeneous paste is formed. Two well-selected stones much facilitate this stage of theprocess; one should be large and flat, the other water-rounded and oval; in fact, a water-worn pebble of about 2lb. weight. By sitting on the stretched skin with the flat stone between the legs, the water and sprinkler at the side, and the pebble between the hands, the paste can be effectually worked up; and it is well to bear in mind that on the perfect homogeneity of this paste depends, in great measure, the quality of the gunpowder.a gunpowder pressThe paste—or devil as it is sometimes called—being thoroughly elaborated, make square flat cakes of it 6in. square and 2in. thick, and wrap them compactly up in cotton cloth or old sheeting four or five times doubled; then stitch up a stout hide bag just large enough to contain all your cakes and their coverings when built in compactly one on the other, and sew up the opening; then, with a chisel, scoop out a cavity in the end of a log just deep enough to half bury your case of cakes; then, with the aid of a neighbouring tree, and a few suitable pieces of wood, which are easily fashioned with the axe, prepare such a press as is shown in the above illustration. The weight should be increased gradually, and the pressure intensified until the cakes are pressed into compact masses. The coverings are now to be removed, and then the process of coming begins, and the help of a corning sieve is required. This is made as follows: Make a wide stout hoop of any pliant wood, and over one of its edges stretch a head of parchment, like that of a banjo, nail or lace it on wet, and when dry it will become perfectly tight, like the head of a tambourine.Now, take a very small-sized key, file off the wards and bow, sharpen the lower edges round the tube with the file until it is converted into a sharp hollow punch. Turn your tambourine upside down on a smooth-faced log of suitable size, and, with a small hammer and your little punch, proceed to perforate the parchment until the head is covered with small round holes. Now fashion from any dry, hard, heavy wood a flat disc 1½in. thick and 4½in. in diameter; this, with the broken cake, is put in the sieve and rattled about forward and back until the small broken granular fragments are in numbers forced through the holes in the parchment, and fall on the skin stretched to receive them. It will be found that among the grains thus formed there will be a certain quantity of fine dust; this can be separated by sweeping the grains over a sloping board on which flannel has been stretched, the grains pass on, the dust remains amongst the fibres of the wool, and can be collected to work up again. The granules can now be placed in a little wooden box and shaken about until rubbed smooth against each other. To finish them off it is well to place a large sheet of iron, copper, tin, or any other metal over a pot of boiling-hot water, throw the now all-but-finished gunpowder on the plate and stir it about until completely dry. A clean frying-pan is by no means a bad instrument for powder drying; take care that it is only placed on hot water, and not subjected to fire heat, or a blow-up will probably follow. Too much caution cannot be used after the powder has been subjected to the granulating process; before that there is little to fear, after it a great deal.
SEARCHING FOR GOLD.
SEARCHING FOR GOLD.
Geology for travellers.
Metals, to identify.
Hints to gold searchers.
In travelling through little known or comparatively undescribed countries, it will be well for the experienced traveller to closely investigate and carefully study the geology of the region he is passing through; outcropping rocks and the stones of the river beds should be closely investigated. Sand should be gathered on the borders of the deep pools, dried, spread out on paper, and examined under the lens. Thus will the formation of inaccessible mountain regions be often brought to light. The winter ices and spring floods, by breaking up and disintegrating the rocks they flow through, gradually, by friction and the grinding power of water-moved boulders, reduce the detrituswhich accompanies them to sand, more or less ponderous according to the metallic elements of which it is formed. Thus, by the breaking up of quartz veins by the agencies just referred to, gold is released from its matrix to enrich the sands and shingle beds of certain rivers. Alluvial tin is in the same way set free in grains and nodules from the granitic or other formations in which it resides, and, water borne, travels onward until arrested by some deep pit or crevice in the river bed, where it remains until disturbed by floods of more than ordinary magnitude, or the pick and shovel of the miner. Our space will not admit of our dealing at length with the indications of gold or other metals, or of the regions in which the precious metals and gems are to be sought.Metals, to identify.We shall, therefore, content ourselves by giving a few plain, and we trust practical, hints for the finding and identification of such metals, stones, &c., as the traveller is likely to meet with. First in importance we class gold; and, although precarious and uncertain in the bulk of its deposits, is more generally distributed throughout the earth’s surface than any other metal.Hints to gold searchers.Clay slate formations, traversed by iron-stained quartz dykes, are well worth investigating; and most of the streams which flow through such formations will be found, on careful examination, more or less auriferous. In prospecting a stream, or river bed, choose localities where the stream, after a sharp descending run, has impinged against a perpendicular bank, forming an eddy before flowing onward. Dig away boldly all the top deposit until the bed rock is reached. Rout out all the depressions, crevices, and holes in this, scooping up all the clay, gravel, and grit they may contain. Place all this in convenient quantities in a broad shallow metal pan or dish, add water to it, rub it about briskly with the hand, pour away all the dirty water, add more, shake it about, give a sweeping rotatory motion to your pan, pick out all large lumps of stone or quartz, giving a sharp look at the latter; still add water, and work the pan until nothing but fine clear sand remains in it. A dexterous rolling, tilting motion is given by the initiated, which at once clears away the baser fragments, and reveals the “colour,” as the gold dust is called by the miners. A broad shovel is at times used somewhat in the same manner, the handle being held as shown in the full-page illustration “Searching for Gold,” when the process is called vanning.
mining tools
mining tools
Mining and miners’ tools.
To carry out a regular system of investigation among quartz reefs, mineral veins, and metalliferous rocks, certain tools and appliances will be needed—picks of Cornish pattern, such as is represented in the aboveillustration, sets of steel borers, with cockscomb ends, sets of steel gads or wedges, borer, steel and gad steel in bars, blasting powder, safety match in coils, some heavy hammers, a portable forge (such as ishere represented), set of smith’s tools, shovel blades, spare pick-heads, and hilts of ash, &c. When it is deemed requisite to blast a portionof rock, the borer and hammer are used much as shown in theannexed illustration. One man, sitting on the ground, holds the borer upright and turns it freely round, whilst his assistant strikes it with the hammer. A little water dropped from time to time down the hole keeps the bit cool, and facilitates the operation. As sludge collects, it is removed with a species of scraper, fashioned from the end of an iron bar. A small rod or stick, with its end fibres frayed and set up like a mop, is used for drying out the hole. Should it be in wet ground, where moisture remains in spite of swabbing out, a cartridge composed of tallowed cotton or oiled paper, may be used to inclose the powder in. According to the old-fashioned plan, which some miners still follow, a long pointed copper rod or needle was pressed into the charge after it had been rammed into the bottom of the hole. Round this rod clay, pulverised clay, slate, &c., was closely packed, and driven with a copper tamping rod until the hole was compactly filled up. The needle was now withdrawn, and a match, composed of a long marsh reed filled with mealed powder, thrust down the orifice until the charge was reached, when the upper end was held in its place by clay. A bit of rag, smeared with moistened powder, was attached to the head of the reed, which, when fired, burned long enough to afford time for the miners to shelter themselves from the effects of the explosion. Since the introduction of the so-called patent safety match, it has been with great advantage substituted for the reed; the burning of thismatch or fuse is generally so uniform, that it has only to be cut according to the distance between the hole and the place of shelter. Even this great improvement in the means of ignition falls very short of exploding by voltaic electricity, which should always, when practicable, be had recourse to. The wandering miner and explorer will, however, seldom be able to avail himself of its valuable aid, or the use of gun cotton or nitrate of glycerine, which agents have of late been much lauded as substitutes for gunpowder in mining operations.
It not unfrequently happens that diamonds and other precious stones are found in river beds, and such other localities as miners are in the habit of examining. We therefore offer a few hints and directions for the identification of these in their rough state, as given by Professor Tennant:
Precious Stones
Precious stones, to identify.
“Fig. 1 is an octahedron; Fig. 2 an octahedron having six planes on the edges; Fig. 3, dodecahedron with rhombic faces; Figs. 4, 5, and 6 are rarer forms. Out of 1000 diamonds I have generally found about one of the form of Fig. 6; about ten like Fig. 5; fifty like Fig. 4; and the remainder like 1, 2, 3, in about an equal proportion. With regard to the size and weight of diamonds, 500 out of 1000 which came in the same parcel were found smaller than Fig. 1, which is the exact size of a diamond weighing half a carat; 300 were of the size 3, 4, 5, and 6—none of these exceeded a carat in weight; eighty of the size 2 weighed a carat and a half; only one was as large as Fig. 16—this weighed 24 carats. The remainder varied from 2 to 20 carats, a carat being equal to three grains and one-sixth troy. Fig. 7 consists of a conglomerated mass of quartz pebbles rounded through having been water-worn, a crystal of diamond, the size of a small pea, and various grains of gold, the whole cemented together by oxide of iron. This specimen is peculiarly interesting at the present time, as showing the association of diamonds with gold. In 1844 a slave was searching for gold in the bed of a river in the province of Bahia, and discovered diamonds. It being a new locality for diamonds, 297,000 carats were collected in two years, which produced upwards of 300,000l.I see no reason why diamonds should not be found in Australia, Canada, California, as well as in those other gold districts from which they have hitherto been obtained. The value of the most inferior diamonds, unfit for jewellery, is 50l.per ounce. Could they be found in sufficient abundance to be sold at 5l.per ounce, the benefit to the arts would be incalculable. Not only would the seal engraver, watchmaker, lapidary, glazier, &c., be able to procure them at easier prices, but numerous substances would be rendered useful which at present cannot be profitably worked owing to the high price of diamonds.
“Figs. 8 to 11 represent four crystals of corundum. This substance is commonly found in six-sided prismatic crystals, and frequently terminated at each end by six-sided pyramids. When transparent, and of a blue colour, it is known in jewellery as the sapphire; when merely of a red colour, it is called Oriental ruby; and when this colour is of a rich depth, the stone is more valuable than even the diamond.
“Figs. 12 to 14. Three crystals of spinel-ruby. It is of various shades of red, and is easily distinguished from corundum by the peculiarity of its crystalline form and inferior hardness.
“Figs. 15 and 16. Crystals of garnet. These are chiefly found in the form of the rhombic dodecahedron; are occasionally of a beautiful red colour; when semi-transparent, are called by the jewellers “carbuncles.” They are of comparatively little value.
“Figs. 17 and 18. Two rhombic prisms of topaz. It is found in rivers, frequently with all the edges and angles of the original crystalworn off, and presenting a round appearance, in which state it is often mistaken for the diamond, owing to the colour and specific gravity of each being the same. It may, however, easily be distinguished from it by the difference of the hardness and fracture. The diamond yields readily to mechanical division parallel to all the planes of the regular octahedron, the topaz only at right angles to the axis of the crystal.
“Fig. 20. Tourmaline. A crystal having six sides, deeply striated in the longitudinal direction, and terminated by a three-sided pyramid; colour varying from black to brown and green. Transparent specimens are useful to the philosopher in experiments on polarised light.
“Fig. 21. Crystal of transparent quartz or “rock crystal,” frequently called a “diamond” in the mining districts, as “Bristol diamond,” a “Cornish diamond,” &c. The crystal represented by this figure was brought from California by a person who refused 200l.for it, under the impression that it was a real diamond, because it scratched glass and could not be scratched with a file. Its real value, however, is not more than 2s.6d.
“Fig. 22. Beryl, presents a six-sided prism, and is usually of a green colour.”
River pearls, to find.
When substances are found which are supposed to be precious stones, the file test should be at once applied; if the teeth of the instrument “bite,” as it is called, or cut into the substance, it will be at once fair to infer that some inferior mineral has been discovered. The bit of sapphire from the case may also be called into use, and if the stone you have found is of white colour, and a corner of your sapphire bites or scratches it, there is no hope of its being a diamond. If on weighing it the specific gravity of the specimen is found to be less than 3·9, it will not turn out to be a ruby or sapphire. The application of heat is another test, as if no electricity is manifested it will not turn out to be a gargoon or a topaz. If, on testing it on your piece of flint glass, the surface of that is bitten by the specimen, it will probably be found to be either rock crystal, quartz, or perchance beryl. The rivers of many countries, our own amongst the number, not unfrequently contain large mussel-like shells; these are the fresh-water pearl mussels (Unio margaritiferus), and the pearls which these at times contain areof considerable value, and well repay being looked for when the rivers are low.
“All is not gold that glitters.” Sulphuret of iron and yellow mica are not unfrequently mistaken by the inexperienced for gold, and we have not unfrequently had some little difficulty in convincing the sanguine discoverer of his error. Sulphuret of iron, pyrites, or the mundic of the miners, is a bright yellow glittering mineral, which sometimes has gold associated with it. The differences between it and gold are sufficiently marked. Strike the suspected fragment on a hard substance with a hammer, and if “mundic,” it at once becomes reduced to minute fragments, whilst gold would be only slightly flattened. Gold is malleable; mundic is not. Gold can be cut with the pocket-knife just as easily as copper; mundic resists the knife, turns its edge, and will strike fire against its back, giving out sulphurous fumes. Mundic, after being made red hot, is attracted by the magnet; gold never is. Hot nitric acid causes it to decompose with much effervescence, leaving such spangles of gold as it may contain free in the bottom of the test tube. Gold dust is readily taken up by quicksilver; mundic is not. Yellow mica is so much lighter than gold that its comparative want of ponderability should at once distinguish it; a small portion placed on an iron bar, and heated in the fire to redness becomes, on cooling, flakey and lustreless, whilst gold would remain unaltered; it floats on the surface of mercury, refusing to unite with it, whilst gold is immediately converted into an amalgam. Sulphuret of copper, or copper ore as it is usually called, breaks freely under the hammer, but can be cut easily with the knife, only instead of producing a solid metallic chip it crumbles into powder, just as soft stone or chalk would. Alluvial tin can in no case be mistaken for either gold, silver, or copper. It is dark coloured, breaks into powder under the hammer, and is exceedingly ponderous. With the so-calledrosinandwoodtin we cannot deal here, as the explorer is not very likely to find them. Minute fragments of stream tin are to be easily distinguished from small bits of iron ore by first heating them red hot, and then subjecting them to the magnet; iron will be attracted, tin will not.
smelting iron ore
Iron ore, to smelt.
Many wild countries produce iron ore of remarkable purity, and a number of native tribes, by a rough system of smelting, contriveto obtain enough metal for the manufacture of their weapons, implements, &c. The greater the purity of the metal, the less difficulty will be experienced in dealing with it. Should the explorer at any time be called on to smelt a little iron ore, he may proceed as follows: Build a turret-shaped furnace, proportioned to the quantity of ore to be treated, line it with ant-hill clay, or common clay and sand, leaving a hole in the front near the bottom, which has a temporary stopper of clay placed in it, and another orifice about 2ft. up the back for the air blast to enter at. Either a large pair of double bellows, compressible skin air-bags, such as we have before described, or blowing cylinders, such as are represented in the annexedillustration, must be set up at a convenient distance from the back of the furnace. These cylinders are used by the inhabitants of New Guinea instead of bellows, and answer remarkably well. They are composed of two hollow tree trunks, placed side by side; a wooden tube, which serves to let the air out, unites them; and a man or boy sits on the tops of the tubes, and works alternately up and down a couple of mop-shaped pistons, which are made from poles armed at the ends with bundles of fibre, feathers, or dry grass, so adjusted that they expand on being thrust down and collapse on being drawn up. As one piston man gets fatigued, another takes his place; thus a continuous stream of air is kept up. Whatever method of blastis decided on, it must be so arranged as to be continuous and powerful. When the interior of the furnace is quite dry, throw in a good quantity of well-burned charcoal; then a layer of split dry wood until it reaches about 1ft. above the entrance of the blast; then another layer of charcoal and dry cow dung a few inches deep; then sprinkle in loosely a layer of broken iron ore, mixed with a little limestone if you can get it; then another layer of charcoal and dry cow dung, and another of ore; and so on until the furnace is all but full, only one layer of wood being used. Now through the blast entrance introduce some well-ignited and glowing embers from your fire; put in the tube of your blast, which may be of baked clay; lute it fast in its place, so as to prevent any escape of air; and proceed to blow, when your furnace will soon be in a state of active ignition and glow. Keep up the blast steadily, and as the contents of the furnace sink down add to them from above layer by layer as before directed, until it is considered that enough metal has been cast in. So soon as it is thought probable that the iron has melted, a small portion of the clay of the tap-hole may be removed with an iron bar, when, if in a sufficiently fluxed condition, the iron will run freely out into long shallow pits dug to receive it. The iron thus procured is called bloom, and has to be heated in pieces in the forge fire, and thoroughly roasted and thumped about until it is soft and tough enough for general use. The natives do not as a rule wait for their iron to flow, but open the furnace when it cools down, and then drag out such bloom as may have settled to the bottom. Excellent steel is made from iron thus procured by the natives of the hill districts of India, by putting it in small earthen crucibles with charcoal, rice, chaff, peroxide of manganese, and green leaves. These pots are then luted down with clay, and placed in a clay furnace heated with dry cow dung and charcoal. Here they remain for a considerable time, when the fire is allowed to burn out; the pots are then, when cool, removed, and the steel taken out to be fashioned by the hand of the smith into any form required. We have used a great deal of both iron and steel prepared as above described, and found both of admirable quality.