AMADOU. The French name of the spongy combustible substance, called in Germanzunderschwamm, prepared from a species of agaric, theboletus igniarius, a kind of mushroom, which grows on the trunks of old oaks, ashes, beeches, &c. It must be plucked in the months of August and September. It is prepared by removing the outer bark with a knife, and separating carefully the spongy substance of a yellow brown colour, which lies within it, from the ligneous matter below. This substance is cut into thin slices, and beat with a mallet to soften it, till it can be easily pulled asunder between the fingers. In this state theboletusis a valuable substance for stopping oozing hemorrhages, and some other surgical purposes. To convert it into tinder it must receive a finishing preparation, which consists in boiling it in a strong solution of nitre; drying it, beating it anew, and putting it a second time into the solution. Sometimes, indeed, to render it very inflammable, it is imbued with gunpowder, whence the distinction of black and brown amadou.All the puff balls of the lycopodium genus of plants, which have a fleshy or filamentous structure, yield a tinder quite ready for soaking in gunpowder water. The Hindoos employ a leguminous plant, which they callsolu, for the same purpose. Its thick spongy stem, being reduced to charcoal, takes fire like amadou.
AMADOU. The French name of the spongy combustible substance, called in Germanzunderschwamm, prepared from a species of agaric, theboletus igniarius, a kind of mushroom, which grows on the trunks of old oaks, ashes, beeches, &c. It must be plucked in the months of August and September. It is prepared by removing the outer bark with a knife, and separating carefully the spongy substance of a yellow brown colour, which lies within it, from the ligneous matter below. This substance is cut into thin slices, and beat with a mallet to soften it, till it can be easily pulled asunder between the fingers. In this state theboletusis a valuable substance for stopping oozing hemorrhages, and some other surgical purposes. To convert it into tinder it must receive a finishing preparation, which consists in boiling it in a strong solution of nitre; drying it, beating it anew, and putting it a second time into the solution. Sometimes, indeed, to render it very inflammable, it is imbued with gunpowder, whence the distinction of black and brown amadou.
All the puff balls of the lycopodium genus of plants, which have a fleshy or filamentous structure, yield a tinder quite ready for soaking in gunpowder water. The Hindoos employ a leguminous plant, which they callsolu, for the same purpose. Its thick spongy stem, being reduced to charcoal, takes fire like amadou.
AMALGAM. When mercury is alloyed with any metal, the compound is called an amalgam of that metal; as, for example, an amalgam of tin, bismuth, &c.
AMALGAM. When mercury is alloyed with any metal, the compound is called an amalgam of that metal; as, for example, an amalgam of tin, bismuth, &c.
AMALGAMATION. This is a process used extensively in extracting silver and gold from certain of their ores, founded on the property which mercury has to dissolve thesemetals as disseminated in the minerals, and thus to separate them from the earthy matters. SeeMercury,Metallurgy, andSilver.
AMALGAMATION. This is a process used extensively in extracting silver and gold from certain of their ores, founded on the property which mercury has to dissolve thesemetals as disseminated in the minerals, and thus to separate them from the earthy matters. SeeMercury,Metallurgy, andSilver.
AMBER. (Succin, Fr.;Bernstein, Germ.) A mineral solid, of a yellow colour of various shades, which burns quite away with flame, and consists of carbon, hydrogen, and oxygen, in nearly the same proportions, and the same state of combination, as vegetable resin. Its specific gravity varies, by my trials, from 1·080 to 1·085. It becomes negatively and powerfully electrical by friction. When applied to a lighted candle it takes fire, swells considerably, and exhales a white smoke of a pungent odour; but does not run into drops. Copal, which resembles it in several respects, differs in being softer, and in melting into drops at the flame; and mellite, or honey-stone, which is a mineral of a similar colour, becomes white when laid on a red-hot coal.The texture of amber is resino-vitreous, its fracture conchoidal, and lustre glassy. It is perfectly homogeneous; sufficiently hard to scratch gypsum, and to take a fine polish. It is, however, scratched by calcareous spar. When amber is distilled in a retort, crystalline needles of succinic acid sublime into the dome, and oil of amber drops from the beak into the receiver. Fossil resins, such as that of Highgate, found in the London clay formation, do not afford succinic acid by heat; nor does copal. Amber is occasionally found of a whitish and brownish colour.The most interesting fact relative to this vegeto-mineral is its geological position, which is very characteristic and well determined. It is found almost uniformly in separate nodules, disseminated in the sand, clay, or fragments of lignite of the plastic clay, and lignite formation, situated between thecalcaire grossier(crag limestone) of the tertiary strata above, and the white chalk below. The size of these nodules varies from a nut to a man’s head; but this magnitude is very rare in true amber. It does not occur either in continuous beds, like the chalk flints, nor in veins; but it lies at one time in the earthy or friable strata, which accompany or include the lignites; at another, entangled in the lignites themselves; and is associated with the minerals which constitute this formation, principally the pyrites, the most abundant of all. The pieces of amber found in the sands, and other formations evidently alluvial, those met with on the sea-coasts of certain countries, and especially Pomerania, come undoubtedly from the above geological formation; for the organic matters found still adhering to the amber leave no doubt as to its primitive place. Amber does not, therefore, belong to any postdiluvian or modern soil, since its native bed is covered by three or four series of strata, often of considerable thickness, and well characterised; proceeding upwards from the plastic clay which includes the amber: these are, the crag limestone, the bone gypsum, with its marls, the marly limestone, the upper marl sandstone, which covers it, and, lastly, the freshwater or lacustrine formation, often so thick, and composed of calcareous and siliceous rocks.The amber bed is not, however, always covered with all these strata; and it is even rare to see a great mass of one of them above the ground which contains it; because, were it buried under such strata, it would be difficult to meet with such circumstances as would lay it spontaneously open to the day. But by comparing observations made in different places, relatively to the patches of these formations, which cover the amber deposits, we find that no other mineral formations have been ever seen among them except those above detailed, and thus learn that its geological locality is completely determined.The proper yellow amber, therefore, or the Borussic, from the country where it has been most abundantly found, belongs to the plastic clay formation, intermediate, in England, between the chalk and the London clay. It is sometimes interposed in thin plates between the layers of the lignites, but more towards the bark of the fibrous lignites, which retain the form of the wood, than towards the middle of the trunk of the tree; a position analogous to that of the resinous matters in our existing ligneous vegetables. The fibrous lignites which thus contain amber belong to the dicotyledinous woods. Hence that substance seems to have been formed during the life of the vegetable upon which it is now encrusted. It must be remembered that the grounds containing the amber are often replete with the sulphates of iron, alumina, and lime, or at least with the pyritous elements of these salts. Some specimens of amber have a surface figured with irregular meshes, indicating a sort of shrinkage from consolidation, and consequently a matter that was at one time fluid, viscid, or merely soft. From optical examination, Dr. Brewster has concluded amber to be of vegetable origin.The different bodies included in the amber, distinguishable from its transparence, demonstrate, indeed, in the most convincing manner, its primitive state of liquidity or softness. These bodies have long exercised the skill of naturalists. They are generally insects, or remains of insects, and sometimes leaves, stalks, or other portions of vegetables. Certain families of insects occur more abundantly than others. Thus thehymenoptera, or insects with four naked membranaceous wings, as the bee and wasp, and thediptera, or insects with two wings, as gnats, flies, gadflies, &c.; then come the spider tribe;somecoleoptera(insects with crustaceous shells or elytra, which shut together, and form a longitudinal suture down the back,) or beetles, principally those which live on trees; such as theelaterides, or leapers, and thechrysomelida. The lepidoptera, or insects with four membranaceous wings, and pterigostea covered with mail-like scales, are very rare in amber. We perceive from this enumeration, which results from the labours of Germar, Schweiger, &c., that the insects enveloped in this resinous matter are in general such as sit on the trunks of trees, or live in the fissures of their bark. Hitherto, it has not been found possible to refer them to any living species; but it has been observed in general that they resemble more the insects of hot climates than those of the temperate zones.The districts where amber occurs in a condition fit for mining operations are not numerous; but those in which it is met with in small scattered bits are very abundant. Its principal exploitation is in Eastern Prussia, on the coasts of the Baltic sea, from Memel to Dantzick, particularly in the neighbourhood of Konigsberg, along the shore which runs north and south from Grossdirschheim to Pillau, and in several other places near Dantzick.It is collected upon this coast in several ways; 1. In the beds of small streams which run near the villages, and in rounded fragments without bark, or in the sand-banks of rivers, in pieces thrown back by the sea, and rounded by the waves. 2. If the pieces thrown up by the waters are not numerous, the fishers, clothed in a leather dress, wade into the sea up to the neck, seek to discover the amber by looking along its surface, and seize it with bag nets, hung at the end of very long poles. They conclude that a great deal of amber has been detached from the cliffs by the sea, when many pieces of lignite (wood coal) are seen afloat. This mode of collecting amber is not free from danger, and the fishers, therefore, advance in troops, to lend each other aid in case of accident; but their success, even thus, is most precarious. 3. The third method of searching for amber is a real mining operation: it consists in digging pits upon the borders of the sandy downs, sometimes to a depth of more than 130 feet. 4. The last mode is by exploring the precipitous sea cliffs in boats, and detaching masses of loose soil from them with long poles terminating in iron hooks; a very hazardous employment. They search the cliffs with great care at the level, where the amber nodules commonly lie, and loosen the seams with their hooks; in which business the boats are sometimes broken against the precipices, or sunk by an avalanche of rubbish.Amber occurs in Sicily, disseminated in beds of clay and marl, which lie below the crag limestone. It is accompanied with bitumen; and, though a scanty deposit, it is mined for sale. The pieces are coated with a kind of whitish bark, present a variety of colours, and include many insects. Amber is found in a great many places in the sandy districts of Poland, at a very great distance from the sea, where it is mixed with cones of the pine. In Saxony it is met with in the neighbourhood of Pretsch and Wittemberg, in a bituminous clay mingled with lignite. At the embouchure of the Jenissey, in Siberia, it occurs likewise along with lignite; as also in Greenland.Fine amber is considerably valued for making ornamental objects, and the coarser kinds for certain uses in chemistry, medicine, and the arts. The oriental nations prize more highly than the people of Europe trinkets made of amber; and hence the chief commerce of the Pomeranian article is with Turkey. The Prussian government is said to draw an annual revenue of 17,000 dollars from amber. A good piece of a pound weight fetches 50 dollars. A mass weighing 13 pounds was picked up not long since in Prussia, for which 5000 dollars were offered, and which would bring, in the opinion of the Armenian merchants, from 30,000 to 40,000 dollars at Constantinople. At one time it was customary to bake the opaque pieces of amber in sand, at a gentle heat, for several hours, in order to make it transparent, or to digest it in hot rapeseed oil, with the same view; but how far these processes were advantageous does not appear.When amber is to be worked into trinkets, it is first split on a leaden plate at a lathe (seeGems,Cutting of), and then smoothed into shape on a Swedish whetstone. It is polished on the lathe with chalk and water, or vegetable oil, and finished by friction with flannel. In these processes the amber is apt to become highly electrical, very hot, and even to fly into fragments. Hence, the artists work the pieces time about, so as to keep each of them cool, and feebly excited. The men are often seized with nervous tremors in their wrists and arms from the electricity. Pieces of amber may be neatly joined by smearing their edges with linseed oil, and pressing them strongly together, while they are held over a charcoal fire. Solid specimens of amber, reported to have been altogether fused by a particular application of heat, are now shown in the royal cabinet of Dresden.A strong and durablevarnishis made by dissolving amber in drying linseed oil. For this purpose, however, the amber must be previously heated in an iron pot, over a clear red fire, till it soften and be semi-liquefied. The oil, previously heated, is to be now poured in, with much stirring, in the proportion of 10 ounces to the pound of amber;and after the incorporation is complete, and the liquid somewhat cooled, a pound of oil of turpentine must be added. Some persons prescribe 2 ounces of melted shellac, though by this means they are apt to deepen the colour, already rendered too dark by the roasting.The fine black varnish of the coachmakers is said to be prepared by melting 16 ounces of amber in an iron pot, adding to it half a pint of drying linseed oil, boiling hot, of powdered resin and asphaltum 3 ounces each: when the materials are well united, by stirring over the fire, they are to be removed, and, after cooling for some time, a pint of warm oil of turpentine is to be introduced.Theoil of amberenters into the composition of the old perfume calledeau de luce; and is convertible, by the action of a small quantity of strong nitric acid, into a viscid mass like shoemakers’ rosin, which has a strong odour of musk, and, under the name of artificial musk, has been prescribed, in alcoholic solution, as a remedy against hooping cough, and other spasmodic diseases.Acid of amber (succinic acid) is a delicate reagent, in chemistry, for separating red oxide of iron from compound metallic solutions.
AMBER. (Succin, Fr.;Bernstein, Germ.) A mineral solid, of a yellow colour of various shades, which burns quite away with flame, and consists of carbon, hydrogen, and oxygen, in nearly the same proportions, and the same state of combination, as vegetable resin. Its specific gravity varies, by my trials, from 1·080 to 1·085. It becomes negatively and powerfully electrical by friction. When applied to a lighted candle it takes fire, swells considerably, and exhales a white smoke of a pungent odour; but does not run into drops. Copal, which resembles it in several respects, differs in being softer, and in melting into drops at the flame; and mellite, or honey-stone, which is a mineral of a similar colour, becomes white when laid on a red-hot coal.
The texture of amber is resino-vitreous, its fracture conchoidal, and lustre glassy. It is perfectly homogeneous; sufficiently hard to scratch gypsum, and to take a fine polish. It is, however, scratched by calcareous spar. When amber is distilled in a retort, crystalline needles of succinic acid sublime into the dome, and oil of amber drops from the beak into the receiver. Fossil resins, such as that of Highgate, found in the London clay formation, do not afford succinic acid by heat; nor does copal. Amber is occasionally found of a whitish and brownish colour.
The most interesting fact relative to this vegeto-mineral is its geological position, which is very characteristic and well determined. It is found almost uniformly in separate nodules, disseminated in the sand, clay, or fragments of lignite of the plastic clay, and lignite formation, situated between thecalcaire grossier(crag limestone) of the tertiary strata above, and the white chalk below. The size of these nodules varies from a nut to a man’s head; but this magnitude is very rare in true amber. It does not occur either in continuous beds, like the chalk flints, nor in veins; but it lies at one time in the earthy or friable strata, which accompany or include the lignites; at another, entangled in the lignites themselves; and is associated with the minerals which constitute this formation, principally the pyrites, the most abundant of all. The pieces of amber found in the sands, and other formations evidently alluvial, those met with on the sea-coasts of certain countries, and especially Pomerania, come undoubtedly from the above geological formation; for the organic matters found still adhering to the amber leave no doubt as to its primitive place. Amber does not, therefore, belong to any postdiluvian or modern soil, since its native bed is covered by three or four series of strata, often of considerable thickness, and well characterised; proceeding upwards from the plastic clay which includes the amber: these are, the crag limestone, the bone gypsum, with its marls, the marly limestone, the upper marl sandstone, which covers it, and, lastly, the freshwater or lacustrine formation, often so thick, and composed of calcareous and siliceous rocks.
The amber bed is not, however, always covered with all these strata; and it is even rare to see a great mass of one of them above the ground which contains it; because, were it buried under such strata, it would be difficult to meet with such circumstances as would lay it spontaneously open to the day. But by comparing observations made in different places, relatively to the patches of these formations, which cover the amber deposits, we find that no other mineral formations have been ever seen among them except those above detailed, and thus learn that its geological locality is completely determined.
The proper yellow amber, therefore, or the Borussic, from the country where it has been most abundantly found, belongs to the plastic clay formation, intermediate, in England, between the chalk and the London clay. It is sometimes interposed in thin plates between the layers of the lignites, but more towards the bark of the fibrous lignites, which retain the form of the wood, than towards the middle of the trunk of the tree; a position analogous to that of the resinous matters in our existing ligneous vegetables. The fibrous lignites which thus contain amber belong to the dicotyledinous woods. Hence that substance seems to have been formed during the life of the vegetable upon which it is now encrusted. It must be remembered that the grounds containing the amber are often replete with the sulphates of iron, alumina, and lime, or at least with the pyritous elements of these salts. Some specimens of amber have a surface figured with irregular meshes, indicating a sort of shrinkage from consolidation, and consequently a matter that was at one time fluid, viscid, or merely soft. From optical examination, Dr. Brewster has concluded amber to be of vegetable origin.
The different bodies included in the amber, distinguishable from its transparence, demonstrate, indeed, in the most convincing manner, its primitive state of liquidity or softness. These bodies have long exercised the skill of naturalists. They are generally insects, or remains of insects, and sometimes leaves, stalks, or other portions of vegetables. Certain families of insects occur more abundantly than others. Thus thehymenoptera, or insects with four naked membranaceous wings, as the bee and wasp, and thediptera, or insects with two wings, as gnats, flies, gadflies, &c.; then come the spider tribe;somecoleoptera(insects with crustaceous shells or elytra, which shut together, and form a longitudinal suture down the back,) or beetles, principally those which live on trees; such as theelaterides, or leapers, and thechrysomelida. The lepidoptera, or insects with four membranaceous wings, and pterigostea covered with mail-like scales, are very rare in amber. We perceive from this enumeration, which results from the labours of Germar, Schweiger, &c., that the insects enveloped in this resinous matter are in general such as sit on the trunks of trees, or live in the fissures of their bark. Hitherto, it has not been found possible to refer them to any living species; but it has been observed in general that they resemble more the insects of hot climates than those of the temperate zones.
The districts where amber occurs in a condition fit for mining operations are not numerous; but those in which it is met with in small scattered bits are very abundant. Its principal exploitation is in Eastern Prussia, on the coasts of the Baltic sea, from Memel to Dantzick, particularly in the neighbourhood of Konigsberg, along the shore which runs north and south from Grossdirschheim to Pillau, and in several other places near Dantzick.
It is collected upon this coast in several ways; 1. In the beds of small streams which run near the villages, and in rounded fragments without bark, or in the sand-banks of rivers, in pieces thrown back by the sea, and rounded by the waves. 2. If the pieces thrown up by the waters are not numerous, the fishers, clothed in a leather dress, wade into the sea up to the neck, seek to discover the amber by looking along its surface, and seize it with bag nets, hung at the end of very long poles. They conclude that a great deal of amber has been detached from the cliffs by the sea, when many pieces of lignite (wood coal) are seen afloat. This mode of collecting amber is not free from danger, and the fishers, therefore, advance in troops, to lend each other aid in case of accident; but their success, even thus, is most precarious. 3. The third method of searching for amber is a real mining operation: it consists in digging pits upon the borders of the sandy downs, sometimes to a depth of more than 130 feet. 4. The last mode is by exploring the precipitous sea cliffs in boats, and detaching masses of loose soil from them with long poles terminating in iron hooks; a very hazardous employment. They search the cliffs with great care at the level, where the amber nodules commonly lie, and loosen the seams with their hooks; in which business the boats are sometimes broken against the precipices, or sunk by an avalanche of rubbish.
Amber occurs in Sicily, disseminated in beds of clay and marl, which lie below the crag limestone. It is accompanied with bitumen; and, though a scanty deposit, it is mined for sale. The pieces are coated with a kind of whitish bark, present a variety of colours, and include many insects. Amber is found in a great many places in the sandy districts of Poland, at a very great distance from the sea, where it is mixed with cones of the pine. In Saxony it is met with in the neighbourhood of Pretsch and Wittemberg, in a bituminous clay mingled with lignite. At the embouchure of the Jenissey, in Siberia, it occurs likewise along with lignite; as also in Greenland.
Fine amber is considerably valued for making ornamental objects, and the coarser kinds for certain uses in chemistry, medicine, and the arts. The oriental nations prize more highly than the people of Europe trinkets made of amber; and hence the chief commerce of the Pomeranian article is with Turkey. The Prussian government is said to draw an annual revenue of 17,000 dollars from amber. A good piece of a pound weight fetches 50 dollars. A mass weighing 13 pounds was picked up not long since in Prussia, for which 5000 dollars were offered, and which would bring, in the opinion of the Armenian merchants, from 30,000 to 40,000 dollars at Constantinople. At one time it was customary to bake the opaque pieces of amber in sand, at a gentle heat, for several hours, in order to make it transparent, or to digest it in hot rapeseed oil, with the same view; but how far these processes were advantageous does not appear.
When amber is to be worked into trinkets, it is first split on a leaden plate at a lathe (seeGems,Cutting of), and then smoothed into shape on a Swedish whetstone. It is polished on the lathe with chalk and water, or vegetable oil, and finished by friction with flannel. In these processes the amber is apt to become highly electrical, very hot, and even to fly into fragments. Hence, the artists work the pieces time about, so as to keep each of them cool, and feebly excited. The men are often seized with nervous tremors in their wrists and arms from the electricity. Pieces of amber may be neatly joined by smearing their edges with linseed oil, and pressing them strongly together, while they are held over a charcoal fire. Solid specimens of amber, reported to have been altogether fused by a particular application of heat, are now shown in the royal cabinet of Dresden.
A strong and durablevarnishis made by dissolving amber in drying linseed oil. For this purpose, however, the amber must be previously heated in an iron pot, over a clear red fire, till it soften and be semi-liquefied. The oil, previously heated, is to be now poured in, with much stirring, in the proportion of 10 ounces to the pound of amber;and after the incorporation is complete, and the liquid somewhat cooled, a pound of oil of turpentine must be added. Some persons prescribe 2 ounces of melted shellac, though by this means they are apt to deepen the colour, already rendered too dark by the roasting.
The fine black varnish of the coachmakers is said to be prepared by melting 16 ounces of amber in an iron pot, adding to it half a pint of drying linseed oil, boiling hot, of powdered resin and asphaltum 3 ounces each: when the materials are well united, by stirring over the fire, they are to be removed, and, after cooling for some time, a pint of warm oil of turpentine is to be introduced.
Theoil of amberenters into the composition of the old perfume calledeau de luce; and is convertible, by the action of a small quantity of strong nitric acid, into a viscid mass like shoemakers’ rosin, which has a strong odour of musk, and, under the name of artificial musk, has been prescribed, in alcoholic solution, as a remedy against hooping cough, and other spasmodic diseases.
Acid of amber (succinic acid) is a delicate reagent, in chemistry, for separating red oxide of iron from compound metallic solutions.
AMBERGRIS. (Ambregric, Fr.;Ambra, Germ.).—A morbid secretion of the liver of the spermaceti whale (physeter macrocephalus), found usually swimming upon the sea. It occurs upon the coasts of Coromandel, Japan, the Moluccas, and Madagascar, and has sometimes been extracted from the rectum of whales in the South Sea fishery. It has a gray-white colour, often with a black streak, or is marbled, yellow and black; has a strong but rather agreeable smell, a fatty taste, is lighter than water, melts at 60° C. (140° F.), dissolves readily in absolute alcohol, in ether, and in both fat and volatile oils. It contains 85% of the fragrant substance calledambreine. This is extracted from ambergris by digestion with alcohol of 0·827, filtering the solution, and leaving it to spontaneous evaporation. It is thus obtained in the form of delicate white tufts: which are convertible into ambreic acid by the action of nitric acid. Ambergris is used in perfumery.
AMBERGRIS. (Ambregric, Fr.;Ambra, Germ.).—A morbid secretion of the liver of the spermaceti whale (physeter macrocephalus), found usually swimming upon the sea. It occurs upon the coasts of Coromandel, Japan, the Moluccas, and Madagascar, and has sometimes been extracted from the rectum of whales in the South Sea fishery. It has a gray-white colour, often with a black streak, or is marbled, yellow and black; has a strong but rather agreeable smell, a fatty taste, is lighter than water, melts at 60° C. (140° F.), dissolves readily in absolute alcohol, in ether, and in both fat and volatile oils. It contains 85% of the fragrant substance calledambreine. This is extracted from ambergris by digestion with alcohol of 0·827, filtering the solution, and leaving it to spontaneous evaporation. It is thus obtained in the form of delicate white tufts: which are convertible into ambreic acid by the action of nitric acid. Ambergris is used in perfumery.
AMIANTHUS. A mineral in silky filaments, called alsoAsbestus.
AMIANTHUS. A mineral in silky filaments, called alsoAsbestus.
AMMONIA. A chemical compound, called alsovolatile alkali. This substance, in its purest state, is a highly pungent gas, possessed of all the mechanical properties of the air, but very condensable with water. It consists of 3 volumes of hydrogen and 1 of azote condensed into two volumes; and hence its density is 0·591, atmospheric air being 1·000. By strong compression and refrigeration it may be liquefied into a fluid, whose specific gravity is 0·76 compared to water 1·000.Ammonia gas is composed by weight of 82·53 azote and 17·47 hydrogen in 100 parts. It is obtained by mixing muriate of ammonia, commonly called sal ammoniac, with quicklime, in a retort or still, applying a moderate heat, and receiving the gas either over mercury for chemical experiments, or in water to make liquid ammonia for the purposes of medicine and the arts. Woulfe’s apparatus is commonly employed for this condensation.Ammonia is generated in a great many operations, and especially in the decomposition of many organic substances, by fire or fermentation. Urine left to itself for a few days is found to contain much carbonate of ammonia, and hence this substance was at one time collected in great quantities for the manufacture of certain salts of ammonia, and is still used for its alkaline properties in making alum, scouring wool, &c. When woollen rags, horns, bones, and other animal substances are decomposed in close vessels by fire, they evolve a large quantity of ammonia, which distils over in the form of a carbonate. The main source of ammonia now in this country, for commercial purposes, is the coal gas works. A large quantity of watery fluid is condensed in their tar pits, which contains, chiefly ammonia combined with sulphuretted hydrogen and carbonic acid. When this water is saturated with muriatic acid and evaporated it yields muriate of ammonia, or sal ammoniac, somewhat impure, which is afterwards purified by sublimation. SeeCarbonate of AmmoniaandSal Ammoniac.The soot of chimnies where coal is burned contains both sulphate and carbonate of ammonia, and was extensively employed, at one time, to manufacture these salts.In making water of ammonia on the great scale, a cast iron still should be preferred, and equal weights of quicklime and sal ammoniac should be brought to the consistence of a pap, with water, before the heat is applied. In this case, a refrigeratory worm or globe should be interposed between the adopter tube of the capital of the still and the bottles of Woulfe’s apparatus. The muriate of lime, or chloride of calcium, which is left in the still when the whole ammonia is expelled, is of no value. Water is capable of condensing easily about one third of its weight of ammonia gas, or 460 times its bulk. The following table of the quantity of ammonia in 100 parts by weight of its aqueous combinations, at successive densities, is the result of very careful experiments made by me, and recorded in the Philosophical Magazine for March, 1821.Table of Water of Ammonia or Volatile Alkali, by Dr. Ure.Waterof0·900.Ammo-niain100.Waterin100.Specificgravitybyexperi-ment.Meanspecificgravity.Equivalent primes.10026·50073·5000·90009525·17574·8250·90450·90452Wat. Am.9023·85076·1500·90900·9090924+76,6to18522·52577·4750·91330·913708021·20078·8000·91770·9183821·25+78·75,7to17519·87580·1250·92270·923087018·55081·4500·92750·9278019·1+80·9,8to16517·22582·7750·93200·9326417·35+82·65,9to16015·90084·1000·93630·9375015·9+84·1,10to15514·57585·4250·94100·9424114·66+85·34,11to15013·25086·7500·94550·9473713·60+86·40,12to14511·92588·0750·95100·9523811·9+88·1,14to14010·60089·4000·95640·9574411·2+88·8,15to1359·27590·7250·96140·96256307·95092·0500·96620·967748·63+91·37,20to1256·62593·3750·97160·972977+93,25to1205·30094·7000·97680·978266+94,30to1153·97596·0250·98280·983604·5+95·5,40to1102·65097·3500·98870·989003+97,60to151·32598·6750·99450·99447
AMMONIA. A chemical compound, called alsovolatile alkali. This substance, in its purest state, is a highly pungent gas, possessed of all the mechanical properties of the air, but very condensable with water. It consists of 3 volumes of hydrogen and 1 of azote condensed into two volumes; and hence its density is 0·591, atmospheric air being 1·000. By strong compression and refrigeration it may be liquefied into a fluid, whose specific gravity is 0·76 compared to water 1·000.
Ammonia gas is composed by weight of 82·53 azote and 17·47 hydrogen in 100 parts. It is obtained by mixing muriate of ammonia, commonly called sal ammoniac, with quicklime, in a retort or still, applying a moderate heat, and receiving the gas either over mercury for chemical experiments, or in water to make liquid ammonia for the purposes of medicine and the arts. Woulfe’s apparatus is commonly employed for this condensation.
Ammonia is generated in a great many operations, and especially in the decomposition of many organic substances, by fire or fermentation. Urine left to itself for a few days is found to contain much carbonate of ammonia, and hence this substance was at one time collected in great quantities for the manufacture of certain salts of ammonia, and is still used for its alkaline properties in making alum, scouring wool, &c. When woollen rags, horns, bones, and other animal substances are decomposed in close vessels by fire, they evolve a large quantity of ammonia, which distils over in the form of a carbonate. The main source of ammonia now in this country, for commercial purposes, is the coal gas works. A large quantity of watery fluid is condensed in their tar pits, which contains, chiefly ammonia combined with sulphuretted hydrogen and carbonic acid. When this water is saturated with muriatic acid and evaporated it yields muriate of ammonia, or sal ammoniac, somewhat impure, which is afterwards purified by sublimation. SeeCarbonate of AmmoniaandSal Ammoniac.
The soot of chimnies where coal is burned contains both sulphate and carbonate of ammonia, and was extensively employed, at one time, to manufacture these salts.
In making water of ammonia on the great scale, a cast iron still should be preferred, and equal weights of quicklime and sal ammoniac should be brought to the consistence of a pap, with water, before the heat is applied. In this case, a refrigeratory worm or globe should be interposed between the adopter tube of the capital of the still and the bottles of Woulfe’s apparatus. The muriate of lime, or chloride of calcium, which is left in the still when the whole ammonia is expelled, is of no value. Water is capable of condensing easily about one third of its weight of ammonia gas, or 460 times its bulk. The following table of the quantity of ammonia in 100 parts by weight of its aqueous combinations, at successive densities, is the result of very careful experiments made by me, and recorded in the Philosophical Magazine for March, 1821.
Table of Water of Ammonia or Volatile Alkali, by Dr. Ure.
AMMONIAC, gum-resin. This is the inspissated juice of an umbelliferous plant (thedorema armeniacum) which grows in Persia. It comes to us either in small white tears clustered together, or in brownish lumps, containing many impurities. It possesses a peculiar smell, somewhat like that of assafœtida, and a bitterish taste. It is employed in medicine. Its only use in the arts is for forming a cement to join broken pieces of china and glass, which may be prepared as follows: Take isinglass 1 ounce, distilled water 6 ounces, boil together down to 3 ounces, and add 11⁄2ounce of strong spirit of wine;—boil this mixture for a minute or two; strain it; add, while hot, first, half an ounce of a milky emulsion of gum ammoniac, and then five drams of an alcoholic solution of resin mastic. This resembles a substance sold in the London shops, under the name ofdiamond cement. The recipe was given me by a respectable dispensing chemist.
AMMONIAC, gum-resin. This is the inspissated juice of an umbelliferous plant (thedorema armeniacum) which grows in Persia. It comes to us either in small white tears clustered together, or in brownish lumps, containing many impurities. It possesses a peculiar smell, somewhat like that of assafœtida, and a bitterish taste. It is employed in medicine. Its only use in the arts is for forming a cement to join broken pieces of china and glass, which may be prepared as follows: Take isinglass 1 ounce, distilled water 6 ounces, boil together down to 3 ounces, and add 11⁄2ounce of strong spirit of wine;—boil this mixture for a minute or two; strain it; add, while hot, first, half an ounce of a milky emulsion of gum ammoniac, and then five drams of an alcoholic solution of resin mastic. This resembles a substance sold in the London shops, under the name ofdiamond cement. The recipe was given me by a respectable dispensing chemist.
AMORPHOUS.Without shape.Said of mineral and other substances which occur in forms not easy to be defined.
AMORPHOUS.Without shape.Said of mineral and other substances which occur in forms not easy to be defined.
ANALYSIS. The art of resolving a compound substance or machine into its constituent parts. Every manufacturer should so study this art, in the proper treatises, and schools of Chemistry or Mechanics, as to enable him properly to understand and regulate his business.Anchor
ANALYSIS. The art of resolving a compound substance or machine into its constituent parts. Every manufacturer should so study this art, in the proper treatises, and schools of Chemistry or Mechanics, as to enable him properly to understand and regulate his business.
Anchor
ANCHOR. (Ancre, Fr.;Anker, Germ.) An iron hook of considerable weight and strength, for enabling a ship to lay hold of the ground, and fix itself in a certain situation by means of a rope called the cable. It is an instrument of the greatest importance to the navigator, since upon its taking and keeping hold depends his safety uponmany occasions, especially near a lee shore, where he might be otherwise stranded or shipwrecked. Anchors are generally made of wrought iron, except among nations who cannot work this metal well, and who therefore use copper. The mode in which an anchor operates will be understood from inspection offig.6., where, from the direction of the strain, it is obvious that the anchor cannot move without ploughing up the ground in which its hook or fluke is sunk. When this, however, unluckily takes place, from the nature of the ground, from the mode of insertion of the anchor, or from the violence of the winds or currents, it is calleddragging the anchor. When the hold is good, the cable or the buried arm will sooner break than the ship will drive. Anchors are of different sizes, and have different names, according to the purposes they serve; thus there are,sheet,best bower,small bower,spare,stream, andkedge anchors. Ships of the first class have seven anchors, and smaller vessels, such as brigs and schooners, three.Parts of anchorThe manufacture of anchors requires great knowledge of the structure of iron, and skill in the art of working it. I shall give, here, a brief notice of the improved system introduced by Mr. Perring, clerk of the cheque at Plymouth, in which the proportions of the parts are admirably adapted to the strains they are likely to suffer. Infig.7.Ais theshank;B, thearmorfluke;C, thepalm;D, theblade;E, thesquare;F, thenut;G, thering;H, thecrown.Formerly the shank was made of a number of square iron rods, laid parallel together in a cylindrical form, and bound by iron hoops. When they were welded into one bar, the exterior rods could not fail to be partially burned and wasted by the strong heat. Mr. Perring abated this evil by using bars of the whole breadth of the shank, and placing them right over each other, hooping them and welding them together at two heats into one solid mass. To any one who has seen the working of puddled iron, with a heavy mill hammer, this operation will not appear difficult.He formed the crown with bars similarly distributed with those of the shank. His mode of uniting the flukes to the crown is probably the most valuable part of his invention. The bars and half the breadth of the anchor are first welded separately, and then placed side by side, where the upper half is worked into one mass, while the lower part is left disunited, but has carrier iron bars, orporters, as these prolongation rods are commonly called, welded to the extremity of each portion. The lower part is now heated and placed in the clamping machine, which is merely an iron plate firmly bolted to a mass of timber, and bearing upon its surface four iron pins. One end of the crown is placed between the first of these pins, and passed under an iron strap; the other end is brought between the other pins, and is bent by the leverage power of the elongated rods or porters.Thus a part of the arm being formed out of the crown gives much greater security that a true union of fibres is effected, than when the junction was made merely by a short scarf.The angular opening upon the side oppositeB H,fig.7., is filled with thechock, formed of short iron bars placed upright. When this has been firmly welded, the truss-piece is brought over it. This piece is made of plates similar to the above, except that their edges are here horizontal. The truss-piece is half the breadth of the arm; so that when united to the crown, it constitutes, with the other parts, the total breadth of the arms at those places.The shank is now shut upon the crown; the square is formed, and the nuts welded to it; the hole is punched out for the ring, and the shank is then fashioned.The blade is made much in the way above described. In making the palm, an iron rod is first bent into the approximate form, notching it so that it may more readily take the desired shape. To one end aporterrod is fastened, by which the palm is carried and turned round in the fire during the progress of the fabrication. Iron plates are next laid side by side upon the rod, and the joint at the middle is broken by another plate laid over it. When the mass is worked, its under side is filled up by similar plates, and the whole is completely welded; pieces being added to the sides, if necessary, to form the angles of the palm. The blade is then shut on to the palm, after which the part of the arm attached to the blade is united to that which constitutes the crown. The smith-work of the anchor is now finished.The junction, or shutting on, as the workmen call it, of the several members of an anchor, is effected by an instrument called amonkey, which is merely a mass of iron raised to a certain height, between parallel uprights, as in the pile engine or vertical ram, and let fall upon the metal previously brought to a welding heat.Themonkeyand thehercules, both silly, trivial names, are similar instruments, and are usually worked, like a portable pile engine, by the hands of several labourers, pulling separate ropes. Many other modes of manufacturing anchors have been devised, in which mechanical power is more extensively resorted to.The upper end of the shankF(fig.7.) is squared to receive and hold the stock steadily, and keep it from turning. To prevent it shifting along, there are two knobs or tenon-like projections. The point of the angleH, between the arms and the shank, is sometimes called the throat. The armB Cgenerally makes an angle of 56° with the shankA; it is either round or polygonal, and about half the length of the shank.Thestockof the anchor (fig.6.) is made of oak. It consists of two beams which embrace thesquare, and are firmly united by iron bolts and hoops, as shown in the figure. The stock is usually somewhat longer than the shank, has in the middle a thickness about one-twelfth of its length, but tapers at its under side to nearly one half this thickness at the extremities. In small anchors the stock is frequently made of iron; but in this case it does not embrace the anchor, but goes through a hole made in the square, which is swelled out on purpose.The weight of anchors for different vessels is proportioned to the tonnage; a good rule being to make the anchor in hundredweights one-twentieth of the number of tons of the burden. Thus a ship of 1000 tons would require a sheet anchor of 50 cwts. Ships of war are provided with somewhat heavier anchors.Several new forms and constructions of anchors were proposed under Mr. Piper’s patent of November, 1822, by the adoption of which great advantages as to strength were anticipated over every other form or construction previously made.The particular object was to preserve such a disposition of the fibres of the metal as should afford the greatest possible strength; in doing which the crossing or bending of the fibres at the junctions of the shank, flukes, and crown, where great strength is required, has been avoided as much as possible, so that the fibres are not disturbed or injured.In this respect most anchors are defective; for in connecting the shanks to the crown-pieces, the grain of the metal is either crossed, or so much curved, as to strain the fibre, and consequently induce a weakness where the greatest strength is required. And, further, the very considerable thicknesses of metal which are to be brought into immediate contact by means of the hammer in forging anchors upon the old construction, render it highly probable that faulty places may be left within the mass, though they be externally imperceptible. Mr. Piper’s leading principle was, that the fibre of the metal should run nearly straight in all the parts where strength is particularly required.AnchorFig.8.shows an anchor with one tumbling fluke, which passes through the forked or branched part of the shank. The lower part of this anchor, answering to the crown, has a spindle through it, upon which the fluke turns, and a pin is there introduced for the purpose of confining the fluke when in a holding position. This shank is formed of a solid piece of wrought iron, the fibres of which run straight, and at the crown holes are pierced, which merely bulge the metal without bending the fibres round so as to strain them. The arm and fluke, also, are formed of one piece punched through without curling or crossing the fibre, and the spindle which holds the arm to the crown is likewise straight. This spindle extends some distance on each side of the anchor, and is intended to answer the purpose of a stock; for when either of the ends of the spindle comes in contact with the ground, the anchor will be thrown over into a holding position; or an iron stock may be introduced near the shackle, instead of these projecting ends. In the descent of the anchor, the fluke will fall over towards that side which is nearest the ground, and will there be ready to take hold when the anchor is drawn forward.AnchorFig.9.is another anchor upon the same principle, but slightly varied in form from the last. In this the forked part of the shank is closer than in the former, and there are two arms or flukes connected to the crown-pieces, one of which falls into its holding position as the anchor comes to the ground, and is held at its proper angle by the other fluke stopping against the shank.AnchorFig.10.represents another variation in the form of these improved anchors, having two tumbling flukes, which are both intended to take hold of the ground at the same time. The shank is here, as before, made without crossing the grain of the iron, and the eyes for admitting the bolt at the crown and at the shackle are punched out of the solid, not formed by welding or turning the iron round. In this form a guard is introduced atthe crown, to answer the purpose of a stock, by turning the flukes over into a holding position. The arms and flukes are made, as before described, of the straight fibre of the iron punched through, and the flukes are fixed to the spindle, which passes through the crown-piece.AnchorFig.11.has a shank without any fork, but formed straight throughout; the guard here is an elongated frame of iron, for the same purpose as a stock, and is, with the tumbling flukes, fastened to the spindle, which passes through the crown of the anchor, and causes the flukes to fall into their holding position.The principles of these new anchors are considered to consist in shanks which are made of straight lengths of metal, and finished so that the fibres of the iron shall not be injured by cross-shuts or uncertain welding; also each arm and palm is made in one solid piece, and finished in straight lines, so that the fibres will not be altered, and the shaft-pin or spindle will also be in one straight line; and this is the improvement claimed. These anchors being made in separate pieces, give a great advantage to the workman to execute each part perfectly; for he will not have such heavy weights to lift when hot, which will render these anchors much stronger, with less weight; and if any accident should happen to them, any part may be taken separate from the others to be repaired, and several of those parts of the anchor which may be likely to break may be carried on board, in case of accident. This anchor is so contrived that one of thirty hundred weight may be taken to pieces and put together again, by one man, in twenty minutes; it may also be dismounted, and stowed in any part of the ship, in as little room as straight bars of iron, and speedily put together again.AnchorThe anchor (fig.12.) patented by Mr. Brunton, in February, 1822, has its stock introduced at the crown part, for the purpose of turning it over into a holding position. The shank is perforated through the solid, in two places, with elliptical apertures, for the purpose of giving it a greater stability, and more effectually resisting the strain to which the anchor may be subjected. The stock is a cylindrical iron rod, held at its extremities by lateral braces, which are bolted to the shank.Fig.12.shows the form of the anchor. The shank is seen upright, with one of the flukes projecting in its front; the horizontal iron stock is at bottom; and the oblique braces are bolted to both shank and stock. The ends of the stock, from the shoulder, are formed dove-tailed, and oval in the vertical direction, and are protruded through apertures in the braces, also oval, but in the horizontal direction, and counter sunk. When the ends of the stock have been thus introduced through the holes, the braces are securely bolted to the shank; the ends of the stock are then spread, by hammering into the counter-sunk holes of the braces, and by that means they are made firm.An anchor of this description is considered by the patentee to possess considerable advantage, particularly in point of stability, over the ordinary construction of anchors, and is economical, inasmuch as a less weight of metal will give, upon this plan, an equal degree of strength.An ingenious form of anchor was made the subject of a patent, by Lieutenant Rodgers, of the Royal Navy, in 1828, and was afterwards modified by him in a second patent, obtained in August, 1829. The whole of the parts of the anchor are to be bound together by means of iron bands or hoops, in place of bolts or pins.AnchorsFig.13.is a side view of a complete anchor, formed upon his last improved construction, andfig.14., a plan of the same;fig.15., an end view of the crown and flukes, or arms;fig.16.represents the two principal iron plates,a,a, of which the shank is constructed, but so as to form parts of the stump arms to which the flukes are to be connected.The crown piece is to be welded to the stump piece,c c,fig.16., as well as to theendlof the centre pieceh h, and the scarfsm mare to be cut to receive the arms or flukes. Previously, however, to uniting the arms or flukes with the stump arms, the crown and throat of the anchor are to be strengthened, by the application of the crown slabsn n,fig.16., which are to be welded upon each side of the crown, overlapping the end of the pillarh, and the throat or knees of the stump arms and the crown piece. The stump arms are then to be strengthened in a similar manner, by the thin flat piecesp p, which are to be welded upon each side. The palms are united to the flukes in the usual way, and the flukes are also united to the stump arms by means of the long scarfsm m. When the shank of the anchor has been thus formed, and united with the flukes, the anchor smith’s work may be said to be complete.AnchorsAnother of the improvements in the construction of anchors, claimed under this patent, consists in a new method of affixing the stock upon the shank of the anchor, which is effected in the following manner: infig.14.the stock is shown affixed to the anchor; infig.17.it is shown detached. It may be made either of one or two pieces of timber, as may be found most convenient. It is, however, to be observed that the stock is to be completed before fitting on to the shank. After the stock is shaped, a hole is to be made through the middle of it, to fit that part of the shank to which it is to be affixed. Two stock plates are then to be let in, one on each side of the stock, and made fast by counter sunk nails and straps, or hoops; other straps or hoops of iron are also to be placed round the stock, as usual.In place of nuts, formed upon the shank of the anchor, it is proposed to secure the stock by means of a hoop and a key, shown above and belowJ, infig.14.By this contrivance, the stock is prevented from going nearer to the crown of the anchor than it ought to do, and the key prevents it from sliding towards the shackle.Since fitting the stock to the shank of an anchor, by this method, prevents the use of a ring, as in the ordinary manner, the patentee says that he in all cases substitutes a shackle for the ring, and which is all that is required for a chain cable; but, when a hempen cable is to be used, he connects a ring to the usual shackle, by means of a joining shackle, as infigs.13.and14.Mr. Rodgers proposes, under another patent, dated July, 1833, to alter the size and form of the palms; having found from experience that anchors with small palms will not only hold better than with large ones, but that the arms of the anchor, even without any palms, have been found to take more secure hold of the ground than anchors of the old construction, of similar weight and length. He has, accordingly, fixed upon one-fifth of the length of the arm, as a suitable proportion for the length or depth of the palm. He makes the palms, also, broader than they are long or deep.
ANCHOR. (Ancre, Fr.;Anker, Germ.) An iron hook of considerable weight and strength, for enabling a ship to lay hold of the ground, and fix itself in a certain situation by means of a rope called the cable. It is an instrument of the greatest importance to the navigator, since upon its taking and keeping hold depends his safety uponmany occasions, especially near a lee shore, where he might be otherwise stranded or shipwrecked. Anchors are generally made of wrought iron, except among nations who cannot work this metal well, and who therefore use copper. The mode in which an anchor operates will be understood from inspection offig.6., where, from the direction of the strain, it is obvious that the anchor cannot move without ploughing up the ground in which its hook or fluke is sunk. When this, however, unluckily takes place, from the nature of the ground, from the mode of insertion of the anchor, or from the violence of the winds or currents, it is calleddragging the anchor. When the hold is good, the cable or the buried arm will sooner break than the ship will drive. Anchors are of different sizes, and have different names, according to the purposes they serve; thus there are,sheet,best bower,small bower,spare,stream, andkedge anchors. Ships of the first class have seven anchors, and smaller vessels, such as brigs and schooners, three.
Parts of anchor
The manufacture of anchors requires great knowledge of the structure of iron, and skill in the art of working it. I shall give, here, a brief notice of the improved system introduced by Mr. Perring, clerk of the cheque at Plymouth, in which the proportions of the parts are admirably adapted to the strains they are likely to suffer. Infig.7.Ais theshank;B, thearmorfluke;C, thepalm;D, theblade;E, thesquare;F, thenut;G, thering;H, thecrown.
Formerly the shank was made of a number of square iron rods, laid parallel together in a cylindrical form, and bound by iron hoops. When they were welded into one bar, the exterior rods could not fail to be partially burned and wasted by the strong heat. Mr. Perring abated this evil by using bars of the whole breadth of the shank, and placing them right over each other, hooping them and welding them together at two heats into one solid mass. To any one who has seen the working of puddled iron, with a heavy mill hammer, this operation will not appear difficult.
He formed the crown with bars similarly distributed with those of the shank. His mode of uniting the flukes to the crown is probably the most valuable part of his invention. The bars and half the breadth of the anchor are first welded separately, and then placed side by side, where the upper half is worked into one mass, while the lower part is left disunited, but has carrier iron bars, orporters, as these prolongation rods are commonly called, welded to the extremity of each portion. The lower part is now heated and placed in the clamping machine, which is merely an iron plate firmly bolted to a mass of timber, and bearing upon its surface four iron pins. One end of the crown is placed between the first of these pins, and passed under an iron strap; the other end is brought between the other pins, and is bent by the leverage power of the elongated rods or porters.
Thus a part of the arm being formed out of the crown gives much greater security that a true union of fibres is effected, than when the junction was made merely by a short scarf.
The angular opening upon the side oppositeB H,fig.7., is filled with thechock, formed of short iron bars placed upright. When this has been firmly welded, the truss-piece is brought over it. This piece is made of plates similar to the above, except that their edges are here horizontal. The truss-piece is half the breadth of the arm; so that when united to the crown, it constitutes, with the other parts, the total breadth of the arms at those places.
The shank is now shut upon the crown; the square is formed, and the nuts welded to it; the hole is punched out for the ring, and the shank is then fashioned.
The blade is made much in the way above described. In making the palm, an iron rod is first bent into the approximate form, notching it so that it may more readily take the desired shape. To one end aporterrod is fastened, by which the palm is carried and turned round in the fire during the progress of the fabrication. Iron plates are next laid side by side upon the rod, and the joint at the middle is broken by another plate laid over it. When the mass is worked, its under side is filled up by similar plates, and the whole is completely welded; pieces being added to the sides, if necessary, to form the angles of the palm. The blade is then shut on to the palm, after which the part of the arm attached to the blade is united to that which constitutes the crown. The smith-work of the anchor is now finished.
The junction, or shutting on, as the workmen call it, of the several members of an anchor, is effected by an instrument called amonkey, which is merely a mass of iron raised to a certain height, between parallel uprights, as in the pile engine or vertical ram, and let fall upon the metal previously brought to a welding heat.
Themonkeyand thehercules, both silly, trivial names, are similar instruments, and are usually worked, like a portable pile engine, by the hands of several labourers, pulling separate ropes. Many other modes of manufacturing anchors have been devised, in which mechanical power is more extensively resorted to.
The upper end of the shankF(fig.7.) is squared to receive and hold the stock steadily, and keep it from turning. To prevent it shifting along, there are two knobs or tenon-like projections. The point of the angleH, between the arms and the shank, is sometimes called the throat. The armB Cgenerally makes an angle of 56° with the shankA; it is either round or polygonal, and about half the length of the shank.
Thestockof the anchor (fig.6.) is made of oak. It consists of two beams which embrace thesquare, and are firmly united by iron bolts and hoops, as shown in the figure. The stock is usually somewhat longer than the shank, has in the middle a thickness about one-twelfth of its length, but tapers at its under side to nearly one half this thickness at the extremities. In small anchors the stock is frequently made of iron; but in this case it does not embrace the anchor, but goes through a hole made in the square, which is swelled out on purpose.
The weight of anchors for different vessels is proportioned to the tonnage; a good rule being to make the anchor in hundredweights one-twentieth of the number of tons of the burden. Thus a ship of 1000 tons would require a sheet anchor of 50 cwts. Ships of war are provided with somewhat heavier anchors.
Several new forms and constructions of anchors were proposed under Mr. Piper’s patent of November, 1822, by the adoption of which great advantages as to strength were anticipated over every other form or construction previously made.
The particular object was to preserve such a disposition of the fibres of the metal as should afford the greatest possible strength; in doing which the crossing or bending of the fibres at the junctions of the shank, flukes, and crown, where great strength is required, has been avoided as much as possible, so that the fibres are not disturbed or injured.
In this respect most anchors are defective; for in connecting the shanks to the crown-pieces, the grain of the metal is either crossed, or so much curved, as to strain the fibre, and consequently induce a weakness where the greatest strength is required. And, further, the very considerable thicknesses of metal which are to be brought into immediate contact by means of the hammer in forging anchors upon the old construction, render it highly probable that faulty places may be left within the mass, though they be externally imperceptible. Mr. Piper’s leading principle was, that the fibre of the metal should run nearly straight in all the parts where strength is particularly required.
Anchor
Fig.8.shows an anchor with one tumbling fluke, which passes through the forked or branched part of the shank. The lower part of this anchor, answering to the crown, has a spindle through it, upon which the fluke turns, and a pin is there introduced for the purpose of confining the fluke when in a holding position. This shank is formed of a solid piece of wrought iron, the fibres of which run straight, and at the crown holes are pierced, which merely bulge the metal without bending the fibres round so as to strain them. The arm and fluke, also, are formed of one piece punched through without curling or crossing the fibre, and the spindle which holds the arm to the crown is likewise straight. This spindle extends some distance on each side of the anchor, and is intended to answer the purpose of a stock; for when either of the ends of the spindle comes in contact with the ground, the anchor will be thrown over into a holding position; or an iron stock may be introduced near the shackle, instead of these projecting ends. In the descent of the anchor, the fluke will fall over towards that side which is nearest the ground, and will there be ready to take hold when the anchor is drawn forward.
Anchor
Fig.9.is another anchor upon the same principle, but slightly varied in form from the last. In this the forked part of the shank is closer than in the former, and there are two arms or flukes connected to the crown-pieces, one of which falls into its holding position as the anchor comes to the ground, and is held at its proper angle by the other fluke stopping against the shank.
Anchor
Fig.10.represents another variation in the form of these improved anchors, having two tumbling flukes, which are both intended to take hold of the ground at the same time. The shank is here, as before, made without crossing the grain of the iron, and the eyes for admitting the bolt at the crown and at the shackle are punched out of the solid, not formed by welding or turning the iron round. In this form a guard is introduced atthe crown, to answer the purpose of a stock, by turning the flukes over into a holding position. The arms and flukes are made, as before described, of the straight fibre of the iron punched through, and the flukes are fixed to the spindle, which passes through the crown-piece.
Anchor
Fig.11.has a shank without any fork, but formed straight throughout; the guard here is an elongated frame of iron, for the same purpose as a stock, and is, with the tumbling flukes, fastened to the spindle, which passes through the crown of the anchor, and causes the flukes to fall into their holding position.
The principles of these new anchors are considered to consist in shanks which are made of straight lengths of metal, and finished so that the fibres of the iron shall not be injured by cross-shuts or uncertain welding; also each arm and palm is made in one solid piece, and finished in straight lines, so that the fibres will not be altered, and the shaft-pin or spindle will also be in one straight line; and this is the improvement claimed. These anchors being made in separate pieces, give a great advantage to the workman to execute each part perfectly; for he will not have such heavy weights to lift when hot, which will render these anchors much stronger, with less weight; and if any accident should happen to them, any part may be taken separate from the others to be repaired, and several of those parts of the anchor which may be likely to break may be carried on board, in case of accident. This anchor is so contrived that one of thirty hundred weight may be taken to pieces and put together again, by one man, in twenty minutes; it may also be dismounted, and stowed in any part of the ship, in as little room as straight bars of iron, and speedily put together again.
Anchor
The anchor (fig.12.) patented by Mr. Brunton, in February, 1822, has its stock introduced at the crown part, for the purpose of turning it over into a holding position. The shank is perforated through the solid, in two places, with elliptical apertures, for the purpose of giving it a greater stability, and more effectually resisting the strain to which the anchor may be subjected. The stock is a cylindrical iron rod, held at its extremities by lateral braces, which are bolted to the shank.
Fig.12.shows the form of the anchor. The shank is seen upright, with one of the flukes projecting in its front; the horizontal iron stock is at bottom; and the oblique braces are bolted to both shank and stock. The ends of the stock, from the shoulder, are formed dove-tailed, and oval in the vertical direction, and are protruded through apertures in the braces, also oval, but in the horizontal direction, and counter sunk. When the ends of the stock have been thus introduced through the holes, the braces are securely bolted to the shank; the ends of the stock are then spread, by hammering into the counter-sunk holes of the braces, and by that means they are made firm.
An anchor of this description is considered by the patentee to possess considerable advantage, particularly in point of stability, over the ordinary construction of anchors, and is economical, inasmuch as a less weight of metal will give, upon this plan, an equal degree of strength.
An ingenious form of anchor was made the subject of a patent, by Lieutenant Rodgers, of the Royal Navy, in 1828, and was afterwards modified by him in a second patent, obtained in August, 1829. The whole of the parts of the anchor are to be bound together by means of iron bands or hoops, in place of bolts or pins.
Anchors
Fig.13.is a side view of a complete anchor, formed upon his last improved construction, andfig.14., a plan of the same;fig.15., an end view of the crown and flukes, or arms;fig.16.represents the two principal iron plates,a,a, of which the shank is constructed, but so as to form parts of the stump arms to which the flukes are to be connected.
The crown piece is to be welded to the stump piece,c c,fig.16., as well as to theendlof the centre pieceh h, and the scarfsm mare to be cut to receive the arms or flukes. Previously, however, to uniting the arms or flukes with the stump arms, the crown and throat of the anchor are to be strengthened, by the application of the crown slabsn n,fig.16., which are to be welded upon each side of the crown, overlapping the end of the pillarh, and the throat or knees of the stump arms and the crown piece. The stump arms are then to be strengthened in a similar manner, by the thin flat piecesp p, which are to be welded upon each side. The palms are united to the flukes in the usual way, and the flukes are also united to the stump arms by means of the long scarfsm m. When the shank of the anchor has been thus formed, and united with the flukes, the anchor smith’s work may be said to be complete.
Anchors
Another of the improvements in the construction of anchors, claimed under this patent, consists in a new method of affixing the stock upon the shank of the anchor, which is effected in the following manner: infig.14.the stock is shown affixed to the anchor; infig.17.it is shown detached. It may be made either of one or two pieces of timber, as may be found most convenient. It is, however, to be observed that the stock is to be completed before fitting on to the shank. After the stock is shaped, a hole is to be made through the middle of it, to fit that part of the shank to which it is to be affixed. Two stock plates are then to be let in, one on each side of the stock, and made fast by counter sunk nails and straps, or hoops; other straps or hoops of iron are also to be placed round the stock, as usual.
In place of nuts, formed upon the shank of the anchor, it is proposed to secure the stock by means of a hoop and a key, shown above and belowJ, infig.14.By this contrivance, the stock is prevented from going nearer to the crown of the anchor than it ought to do, and the key prevents it from sliding towards the shackle.
Since fitting the stock to the shank of an anchor, by this method, prevents the use of a ring, as in the ordinary manner, the patentee says that he in all cases substitutes a shackle for the ring, and which is all that is required for a chain cable; but, when a hempen cable is to be used, he connects a ring to the usual shackle, by means of a joining shackle, as infigs.13.and14.
Mr. Rodgers proposes, under another patent, dated July, 1833, to alter the size and form of the palms; having found from experience that anchors with small palms will not only hold better than with large ones, but that the arms of the anchor, even without any palms, have been found to take more secure hold of the ground than anchors of the old construction, of similar weight and length. He has, accordingly, fixed upon one-fifth of the length of the arm, as a suitable proportion for the length or depth of the palm. He makes the palms, also, broader than they are long or deep.