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bone in a circuitous course, enters the cavity of the tympanum, and passing quite across it, is transmitted through the glenoid fissure to a salivary gland under the lower jaw. The object of this singular but uniform course of the chorda tympani is not well understood.

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serves to prevent the entrance of insects and to keep the skin soft. When secreted too abundantly, it is often a cause of deafness, and should be removed as a foreign body by means of a syringe and a solution of soap in warm water. The commonest kind of ear-ache is that caused by inflamDeafness arising from closure of the Eustachian tube mation of this passage, and is generally followed by a has been sometimes cured by dilating that canal by in- copious and foetid secretion poured out by the ceruminous struments passed for that purpose into its outer expanded follicles. If this last long, deafness is sometimes the result extremity through the nostrils, or from the back of the from thickening of the membrane, and has been removed, throat; or by injecting fluids into it by means of a syringe as well as that arising from closure of the Eustachian tube, with a small curved pipe. This latter plan has also been by puncturing the membrane. This part is sometimes successful in curing deafness arising from chronic inflam- ruptured by the spasmodic action of the tensor muscle mation, or morbid secretion within the tympanum. Sup- caused by loud sounds, or by driving air up the Eustachian puration within that cavity, or in the mastoid cells, some- tube in a forcible expiration, as in blowing the nose viotimes results from high inflammation, and has been at-lently. This accident is not followed by the degree of deaftended with fatal consequences by spreading to the bones of the cranium, or along the nerves to the brain, or its placed from the fenestra ovalis: the other ossicula may be ness that might be expected, unless the stapes becomes dismembranes. Cases of this kind generally originate, as we have already stated, in cold with sore throat, and are found lost with comparative impunity for obvious reasons. to occur chiefly in scrofulous habits. Fig. 6.

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Fig. 5.

a

Fig. 5. This is not to be considered as a correct delineation of the organ, being intended only as a diagram, to give a general idea of the relative situations of the several parts. a, superior semi-circular canal; b, posterior ditto;

c, external ditto; d, scala tympani of the cochlea opened, to show r, the fenestra rotunda, entering the tympanum under the promontory; e, Eustachian tube; f, membrana tympani; g, vestibule, not laid open; m, meatus auditorius externus; n, meatus internus, terminating in two fovea.

Fig. 6. View of the pinna, or auricle. The cartilaginous prominences are, a, helix; b, anti-helix; d, tragus; e. anti-tragus: the lobe or lobulus, g. contains no cartilage, being composed only of skin and a fatty cellular tissue. The depressions are c, the scapha or scaphoid (boat-like) fossa; and f, the concha, a term often used to denote the whole appendage of which it is the most important part.

The concha, or pinna, or auricle (for by all these names
the outer appendage of the ear is known), consists of several
resembling an ear-trumpet in different animals. In man
pieces of elastic cartilage expanded in a form more or less
it serves the purpose of collecting the sonorous vibrations
and directing them into the meatus externus much less per-
fectly than in many other animals, which are also provided
with muscles for directing it to the source of sound, which
in man are but rudimentary. It is marked with various
prominences and hollows, of which the names are given in
the figure. It does not seem necessary to describe them
more particularly. The cartilages are bound by ligaments
by a smooth and closely adherent skin.
to the neighbouring prominences of bone, and are covered

porpoises, &c.) are unprovided with this part of the organ;
It may be observed that the aquatic mammalia (whales,
and have a very narrow but long and curved meatus ex-
ternus, passing obliquely into the surface of the head, and in
some instances capable of being closed by a flap of movable
skin to exclude the water.
cochlea is imperfect, the scale making but one turn and
In these animals also the
a half round the modiolus.

3. The external ear consists of the meatus auditorius externus (fig. 5, m) and concha. The former, commencing from the membrana tympani, is an osseous canal in the first part of its course in the adult, and then becomes nothing more than a tubular continuation of the expanded cartilage of the concha, or outer appendage of the ear. It is lined throughout with a delicate skin, covered by thin cuticle, which also covers the outer surface of the membrane. skin, and opening through it on the surface, are numerous Beneath the glandular follicles which secrete the ear-wax or cerumen. In the foetus and new-born infant there is hardly any appearance of this tube; the membrane of the tympanum being close to the surface of the head, stretched upon the inner margin of a bony ring (annulus auditorius) which afterwards increases in length and becomes a tube. In the adult the length of the whole tube may be nearly an inch; but from the obliquity of the membrane, which faces a little downwards, it is longer below than above. Its direction from the membrane is outwards and a little backwards, and it is slightly convex upwards, and rather narrower in the middle than elsewhere. The last mentioned peculiarity is the reason why it is so much easier to introduce beads and other round bodies (as children are apt to do) than to get them out. This however must always be done as soon as possible purpose through the ear, sometimes set with pendant jewels, EAR-RING; a ring hung from a hole, perforated for that when such an accident happens; for the presence of the pearls, or other precious stones. The word is Anglo-Saxon, foreign body sometimes excites great inflammation and ear-hring. swelling, and may lead to very serious consequences. The been worn in almost all countries by women, from the Ornaments of this sort, large or small, have most easy method and the least painful is to direct a strong earliest ages; but more rarely by the men. stream of warm water into the tube with a syringe, which says that the men, in many instances, wore them as amu commonly succeeds immediately if resorted to before there lets. In the Latin of the middle age ear-rings are termed is much swelling. Other means will readily suggest them- pendentes, from the more common form of the ornaments selves; but if resorted to, they should be very tenderly used, usually attached to the ring itself. Sir Richard Hoare, in for the part is extremely sensitive, especially the membrane his antient Wiltshire, describes the ear-rings of a British itself, to rough contact. The wax, which is very bitter, female found in one of the barrows of that county, P. C., No. 561.

Blainville, Comp. Anat.; Bell's Anatomy; Grant's Out(Scarpa, de Auditu; Soemmering, ditto; Breschet, ditto; lines.)

Montfaucon

VOL. IX.-2 I

EARL. The title of count or earl, in Latin comes, is the most antient and widely spread of the subordinate or subject titles. This dignity exists under various names in almost every country in Europe. By the English it is called earl, a name derived to us from the ealderman of the Anglo-Saxons and the eorle of the Danes. By the French it is called comte, by the Spaniards conde, and by the Germans graf, under which generic title are included several distinct degrees of rank,-landgraves, or counts of provinces, palsgraves, or counts palatine, of which there are two sorts, markgraves, or counts of marches, or frontiers, (whence marchio, or marquess), burghgraves, or counts of cities, counts of the empire, counts of territories, and several others. [COUNT; BARON.]

As to the English earls,-after the battle of Hastings, William the Conqueror, as it is well known, recompensed his followers with grants of the lands of the Saxon nobles who had fallen in the battle, to be held of himself as strict feuds; and having annexed the feudal title of earl to the counties of the Saxon earls (with whom the title was only official), he granted them to his principal captains.

These earldoms were of three kinds, all of which were by tenure. The first and highest was where the dignity was annexed to the seisin or possession of a whole county, with 'jura regalia.' In this case the county became a county palatine, or principality, and the person created earl of it acquired royal jurisdiction and seigniory. In short, a county palatine was a perfect feudal kingdom in itself, but held of a superior lord. The counties of Chester, Pembroke, Hexham, and Lancaster, and the bishopric of Durham, have, at different times, been made counties palatine; but it does not appear that the title of earl palatine was given to the most antient and distinguished of them, viz., the earl of Chester, before the time of Henry II., surnamed Fitz-Empress, when the title of palatine was probably introduced from the empire. The earls of Chester created barons and held parliaments, and had their justiciaries, chancellors, and barons of their exchequer. This county palatine reverted to the crown in the reign of Henry III. The second kind of earls were those whom the king created earls of a county, with civil and criminal jurisdiction, with a grant of the third part of the profits of the county court, but without giving them actual seisin of the county. The third kind was where the king erected a large tract of land into a county, and granted it with civil and criminal jurisdiction to be held per servitium unius comitatus.

Under the early Norman kings, all earls, as well as barons, held their titles by the tenure of their counties and baronies; and the grant, or even purchase, with the licence of the sovereign of an earldom or a barony, would confer the title on the grantee or purchaser; but with the solitary exception of the earldom of Arundel, earldoms by tenure have long since disappeared, and in late times the title has been conferred by letters patent under the great seal. Earls have now no local jurisdiction, power or revenue, as a consequence of their title, which is no longer confined to the names of counties or even of places; for several earls, as Earl Spencer, Earl Grey, and others, have chosen their own names, instead of local titles.

The coronet of an English earl is of gold surmounted with pearls, which are placed at the extremity of raised points or rays, placed alternately with foliage. The form of their creation, which has latterly been superseded by the creation by letters patent, was by the king's girding on the sword of the intended earl, and placing his cap and coronet on his head and his mantle on his shoulders. The king styles all earls, as well as the other ranks of the higher nobility or peerage, his cousins. An earl is entitled right honourable, and takes precedence next after marquesses, and before all viscounts and barons. When a marquess has an earldom, his eldest son is called earl by courtesy; but notwithstanding this titular rank, he is only a commoner, unless he be summoned to the House of Lords by such title. So the eldest sons of dukes are called earls where their fathers have an earldom but no marquisate, as the duke of Norfolk, &c.

EARL MARSHAL OF ENGLAND, one of the great officers of state, who marshals and orders all great ceremonials, takes cognizance of all matters relating to honour, arms, and pedigree, and directs the proclamation of peace The curia militaris, or court of chivalry, was formerly under his jurisdiction, and he is still the head of

and war.

the heralds' office, or college of arms. Till the reign of Richard II., the possessors of this office were styled simply Marshals of England: the title of Earl Marshal was bestowed by that king in 1386 on Thomas Lord Mowbray, Earl of Nottingham. The office is now hereditary in the family of Howard, and is enjoyed by the duke of Norfolk. (Chamberlaine's State of England. Dallaway's Inquiries into the Origin and Progress of Heraldry in England, 4to., Glouc. 1793, pp. 93-95.)

EARSHELL. [HALIOTIDE.]

EARTH (Astronomy). In the language of astronomers, the earth is rarely treated as a planet. All the phenomena connected with its motion are seen in the apparent motion of the SUN, to which article we therefore refer.

EARTH, CONTROVERSY ON THE MOTION OF THE. [MOTION OF THE EARTH.]

EARTH, DENSITY OF THE. The fundamental experiment of Cavendish for the determination of this astronomical element being likely to be shortly repeated, it is advisable to defer this article: see therefore WEight of the EARTH.

EARTH, FIGURE OF THE. [GEODESY.]

EARTH. The old chemists imagined that all material substances were ultimately resolvable into four simple bodies, viz. air, fire, water, and earth, which were therefore called the four elements. This term is still occasionally employed in a more restricted sense, as when mention is made of earthy salts, &c. It is now universally admitted, that the bodies called earths are compounds of oxygen and a base, and in fact that they are mostly metallic oxides. The principal earths are alumina [ALUMINUM], barytes [BARIUM], glucina [GLUCINUM], lime [CALCIUM], magnesia [MAGNESIUM], silica [SILICIUM], strontia [STRONTIUM], yttria [YTTRIUM], zirconia [ZIRCONIUM].

EARTH-NUTS are either the fruit of certain plants which bury it below the ground after the flowering is past, as the Arachis hypogæa, Lathyrus amphicarpos, and others, or else the subterranean tubercles of fleshy-rooted plants, such as Bulbocastanum, Cyclamen, Lathyrus tuberosus, Apios tuberosa, and the like.

EARTHENWARE. The art of moulding earthen vessels for domestic use appears to have been practised in the earliest ages, and undoubtedly has been known among the rudest nations. The most antient records allude to the potter's wheel, and we have proof that great skill had been acquired in the manufacture of porcelain of a superior quality in China and in Japan at a very remote date. The little figures, covered with a fine deep-blue glaze, which are deposited with Egyptian mummies, and numerous jars, some specimens of which may be seen in the British Museum, show that in Egypt likewise the art was antiently practised; and indeed we see in Egyptian paintings representations of vessels (presumed to be earthen) which closely resemble those made in Egypt at present, and also the representations of the manufacturing process itself. (Library of Entertaining Knowledge, Egypt, ii. 179.) [COOLERS.] It has been supposed that the Britons understood the pot ter's art before the Roman occupation of this island, since urns of earthenware have been found in barrows in different parts of the kingdom; but other writers affirm, though we believe without proof, that our ancestors were in those days supplied with such articles by the Phoenicians. Vestiges of considerable Roman potteries have been discovered in many parts of this island, particularly in Staffordshire; and there is an interesting account by Governor Pownal (Archæologia, 5th vol., p. 282, &c.) of the discovery of numerous vessels of pottery which were fished up in the Queen's Channel, near Margate. It was for some time supposed that a Roman trading vessel, freighted with pottery, had been wrecked at this place; but on a more particular examination of the spot, called by the fishermen Puddingpan Sand, Roman bricks cemented together, apparently the ruins of a building, were likewise discovered, and on farther investigation it was found that an island existed formerly on this spot on which there had been a large pottery established by the Romans. Many of the earthen pans were recovered in a perfect state, and several of them had the name of Attilianus neatly impressed upon them. The island has long since disappeared, but specimens of the manufacture carried on there were frequently drawn up during the last century in the nets of the Kentish fishermen.

In newly-discovered countries it has been found that the use of earthen vessels is familiar among people otherwise

little acquainted with the arts of civilized life. Vases have been found among the aboriginal Indians on the Mosquito shore which were preserved as memorials of antiquity; and there is strong evidence for believing that these vessels were the manufacture of the country in which they were found, since the remains of antient potteries have been discovered at a considerable distance up the Black River on that coast. In the United States of North America also fragments of pottery made by the native Indians have often been dis-production of cameos and all subjects required to be shown covered.

Although earthenware may be considered as a general term applicable to all utensils composed of earthen materials, it is usual to distinguish such utensils more particularly into three different kinds; namely,-pottery, earthenware, and porcelain. Under the first of these terms are classed the brown stone-ware made into jugs, &c., the red pans and pots in common use, porous vessels, &c. [POTTERY.] Porcelain is distinguished from earthenware as being a semi-vitrified compound, in which one portion remains infusible at the greatest heat to which it can be exposed, while the other portion vitrifies at a certain heat, and thus intimately combines with and envelops the infusible part, producing a smooth, compact, shining, and semi-transparent substance, well known as the characteristic of true porcelain. [PORCELAIN.] At present our notice will be confined to earthenware as used in its distinctive meaning.

saltes: a white and cane coloured porcelain biscuit, both smooth and of a wax-like appearance; and another white porcelainous biscuit, distinguished as jasper, having in general all the properties of the basaltes, with a very important addition, the capability of receiving through its whole substance from the admixture of metallic oxides, the same colours as those oxides communicate to glass or enamel in fusion. This peculiar property renders it applicable to the in bas-relief, as the ground can be made of any colour while the raised figures are of the purest white. Mr. Wedgwood likewise invented a porcelain biscuit nearly as hard as agate, which will resist the action of all corrosive substances, and is consequently peculiarly well adapted for mortars in the chemist's laboratory.

The principal ingredients employed in the composition of all kinds of pottery are clay and flint. The nature of the clay used in the manufacture is of great importance, and so also is the combining of it with a due proportion of flint. The clay principally used in the English potteries is obtained from Dorsetshire and Devonshire; that from the former county is brought from the Isle of Purbeck, and is considered superior to the Devonshire clay. It is of two kinds, distinguished as brown clay and blue clay. The clay from Devonshire is likewise of two distinct qualities, and known as black clay and cracking clay. All these clays are of good working quality, and burn extremely white, being free from any impregnation of iron: the blue clay is considered the best. Another description of clay, superior to either of the former, was first discovered in Cornwall by Mr. Cookworthy, in 1768, and is commonly denominated China clay, because similar in its properties to the porcelain earth of China. It is very white and unctuous, and on investigation has been found to be formed by the gradual disintegration of the felspar of granite. This Cornwall clay is prepared on the spot where it occurs. The partially decomposed granite is broken into small pieces, and thrown into a running stream, where the argillaceous parts are washed off and held suspended in the water, while the mica and quartz being heavier remain at the bottom. At the end of the stream the water is stopped by a dam, and the pure clay gradually subsides. When the whole has separated itself from the water, the latter is drawn off and the solid matter dug out in blocks, which are placed in a situation exposed to a free current of air, and when sufficiently dry are packed in casks for shipment in the state of a fine smooth white powder. Mr. Wedgwood found by analysis that this substance contains sixty parts of alumina and twenty parts of silica; it is infusible, and remains unaltered in the greatest heat of a porcelain furnace. The price of this material is much higher than that of the other English clay; but in the making of porcelain it is indispensable, and it is also used in some of the finer kinds of earthenware.

Until the beginning of the eighteenth century the manufacture of earthenware in this country was confined to a few objects of the coarsest description, and till nearly the close of the same century, the porcelain of China was still in common use on the tables of the wealthy, the home manufacture being confined to articles of the commonest domestic use. Earthenware was likewise largely imported from Holland, and superior kinds from Germany and France. English earthenware and porcelain are now not only brought into general use in this country, to the exclusion of all foreign goods, but earthenware is also largely exported to almost every part of the known world, and even to those countries where the art was previously prosecuted. M. Faujas de Saint Fond observes on this subject-'Its excellent workmanship, its solidity, the advantage which it possesses of sustaining the action of fire, its fine glaze impenetrable to acids, the beauty and convenience of its form, and the cheapness of its price, have given rise to a commerce so active and so universal, that in travelling from Paris to Petersburg, from Amsterdam to the furthest part of Sweden, and from Dunkirk to the extremity of the south of France, one is served at every inn upon English ware. Spain, Portugal, and Italy are supplied with it; and vessels are loaded with it for the East Indies, the West Indies, and the continent of America.' England is mainly indebted to Mr. Wedgwood for the extraordinary improvement and rapid extension of this branch of industry. Before his time our Preparation. In the preparation of the clay some labour potteries produced only inferior fabrics, easily broken or in- is required, before it is in a fit state to be combined with the jured, and totally devoid of taste as to form and ornaments. flint. It is first mixed with very pure water to the consistWedgwood's success was not the result of any fortunate dis-ence of cream: this work is called blunging, and in large covery accidentally made, but was due to patient investigation and unremitting efforts. He called upon a higher class of men than had usually been employed in this manufacture to assist in his labours, and in prosecuting his experiments he was guided by sound scientific principles. The early and signal success which crowned his first exertions only served as an additional motive for continuing his pursuit. One of the principal inventions of Mr. Wedgwood was his table ware, known at present as queen's ware, in consequence of the patronage of the queen, who commanded it to be thus designated. It is characterised as a dense and durable substance, covered with a brilliant glaze, and capable of bearing uninjured sudden alternations of heat and cold. From its first introduction, it was manufactured at so cheap a rate as to render it an article within the reach of all. Soon after, embellishments were introduced which very little enhanced the cost of the article; first, a coloured edge, or painted border was added to the queen's ware, and, lastly, printed patterns covering the whole surface, which at first exhibited very little taste, but by degrees reached the perfection which the art has now attained. Mr. Wedgwood's more beautiful inventions were a terra cotta, which could be made to resemble porphyry, granite, Egyptian pebble, and other beautiful stones of the silicious or crystalline kind: a black porcelainous biscuit, very much The fusible quality of felspar is owing to the presence of about an eighth part of potass. This alkali is separated by decomposition, and thus the fel resembling basalt in its properties, and therefore called ba-pat being deprived of it becomes infusible, as is the case with this China clay. 212

establishments is performed by means of machinery. The
result is a smooth pulp, which is then passed through a
series of sieves of increasing degrees of fineness, till at length
it is perfectly fitted to enter into the composition of the
ware. If the clay were moulded and dried without the ad·
dition of any other body it would certainly crack, as the eva.
poration of the water with which it is mixed, in order to ren-
der it sufficiently plastic for the potter's wheel, would cause
it to shrink in the proportion of one part in twelve in dry-
ing. In combination with silicious earth in proper propor-
tions, it bears the action of fire without cracking, while the
silica materially improves the whiteness of the ware.
The flints are prepared by being burnt in a kiln, and re-
moved while red-hot from the kiln and thrown into cold
water. By this operation their attraction of aggregation is
lessened, and the labour of grinding them is much facilitated.
They are then broken and ground to a very fine powder in
a mill constructed for the purpose, the original of which
was invented by Brindley. A quantity of water is thrown
into the mill with the flints, by which the process is quick-
ened and the health of the workmen is preserved, the finer
particles of flint being thus prevented from flying off and
mixing with the atmosphere which the workmen inhale.

The flints, when reduced to powder, are transferred from when sufficiently dry, to be joined to the vessel. For ornathe mill into another vessel, where more water is added, mental spouts, small ornaments, and other appendages of and the whole is violently agitated by mechanical means; the like nature, the clay is pressed in moulds, the particulaı the finer parts are in consequence held in suspension above, mode of doing which may be readily conceived. and in this state are passed into a reservoir, while the grosser When the vessels are sufficiently dry they have to be particles are left behind at the bottom of the vat. After submitted to the action of fire. For this purpose they are subsidence, the supernatant water is drawn off from the placed in deep boxes called seggars, made of a mixture of reservoir, and the pulverized flint is in a fit state for use. fire-clay and old ground seggars, and capable of sustaining It is considered of a proper fluidity for mixing with the the most intense degree of heat without being fused. The clay when a pint weighs 32 oz., while an equal measure of seggars are of various sizes, shapes, and depths, adapted to the diluted clay should weigh 24 oz. The proportions in the different pieces which they are to contain. In no case which the clay and flint are mixed vary with the quality of is one piece placed in or on another in the seggar, and all the clay, with the nature of the ware to be produced, and is so arranged that the heat may be equally applied to every also with the practice of each manufacturer. Parkes, in his part of each. The seggars, with their contents, are then Essay on the Making of Earthenware,' &c., though his disposed in the oven in such a way that the heat may be knowledge was obtained by a residence of some years at the distributed fairly throughout: they are built one layer on seat of manufacture, does not give any precise information the top of another until they reach nearly to the top of the on the subject, but states that flint forms a fourth, a fifth, oven, each seggar forming a cover to the one beneath it, or a sixth part by weight of the prepared paste. The dilu- and the upper seggar in each pile being always empty. tions of clay and flint being brought together in suitable The oven is of a cylindrical form, and very similar to the proportions, are intimately mixed by agitation, and passed, common kilns used for burning tiles. The process of while in a state of semi-fluidity, through different sieves, baking usually lasts from forty-eight to fifty hours, during whereby the whole becomes a smooth homogeneous mass. which time the heat is gradually increased, as it would be This mixture, technically called slip, is then very carefully injurious to the ware to apply a very high degree at first. evaporated, the mass being frequently stirred and turned To ascertain when the baking has been carried far enough, over lest a part should become improperly hardened while the workman uses tests of common Staffordshire fire-clay, the remainder continues too fluid. When the clay or paste the pyrometer of Wedgwood having been long laid aside. is removed from the slip-kiln, it is well incorporated toge- [PYROMETER.] When the appearance is considered satisther by beating it with wooden mallets, in order to expel factory the firing is discontinued, and the oven is suffered the air which it contains. The next operation is cutting it gradually to cool during twenty-four or thirty hours before into small pieces, which are thrown together again with all the contents are taken out. The ware in this state is called the strength of the workmen; and this process is continued biscuit. The glaze is now applied; the pieces are again until the mass is considered in a complete state of consist-placed in seggars, and conveyed to the glass-oven, where ence. When in this state it should be allowed to remain heat is applied to them of sufficient intenseness to fuse the for a considerable period before being used, since it be-glaze; but the heat must by no means be so great as that comes more intimately united by time than by any mechanical means.

The paste, when taken for use, undergoes the process of slapping, which is similar in its effect to the last operation, and should incorporate the whole mass so completely, that wherever it is cut, it should exhibit a perfectly smooth and uniformly close appearance. The clay, being thus prepared, is now in a fit state for forming into ware. The processes for this purpose are of three different kinds-throwing, pressing, and casting, which are respectively employed according to the form of the article required.

The operation of throwing is performed upon a machine called a potter's lathe, and is used in shaping vessels which have a circular form. By this means the thrower moulds the clay into the form which he desires; and when finished to his satisfaction, he removes his work to a board or shelf, where it is left to dry partially; and when in a particular state of hardness, called the green state, well known to the operator, the vessel is in proper order for being further smoothed and shaped in the turning-lathe, and for being furnished with handles, spouts, or any other addition. The turning-lathe is similar to that used by the turner in wood, and by means of it rings, rims, &c. are formed on the vessels. For making dishes, plates, and other similar shallow vessels, a plaster mould is used, which is placed on the block at the top of the upright spindle of the lathe, and the workman continues the process in nearly a similar manner as in throwing. When sufficiently dry to be taken from the mould, the edges are pared with a sharp knife, and the vessels are placed in piles and left to harden, preparatory to their being baked.

A machine called an engine-lathe, which has a horizontal movement backwards and forwards, in addition to the rotary motion, is used in giving to earthenware a milled edge. Handles, spouts, &c. are fixed on the vessels as soon as they are taken out of the turning-lathe. They are affixed by means of slip, with which the parts designed to come in contact are moistened: in a short time, when dry, the union of the parts is found to be perfect. Handles, &c. are made by pressure in a small metallic cylinder, which has an aperture in the centre of its bottom, to which plugs of various shaped orifices are fitted. There is likewise a piston, so fixed as to be worked by a screw up and down the cylinder. The cylinder, being filled with clay, the piston is inserted, and forces the clay through the orifice at the bottom, and consequently gives it the same form as the aperture through which it was pressed. Being then cut into lengths and bent to the desired shape, the clay is ready,

to which the biscuit has previously been exposed, as the glaze would crack or peel off if the vessels were liable to any further shrinking.

The glaze generally used for common kinds of earthen ware is a compound of litharge and ground flints, in the proportion of ten pounds of the first to four pounds of the latter This method of glazing is however highly objectionable on account of its injurious effects on the health of the workman, while the lead being soluble by acids, makes a most pernicious glaze for vessels which are used for containing many articles of prepared food. Glazes for porcelain and the finer kinds of earthenware are generally made with white lead, ground flints, ground flint-glass, and common salt. But almost every manufacturer uses a peculiar glaze of his own, the manner of making which he keeps in as much mystery as possible. Some glazes are made without the admixture of any lead, and in the whole of the better glazes this ingredient enters in so small a quantity as not to be injurious. The manner of applying the glaze is, to reduce the ingredients to powder, mix them with water to the consistence of cream, and then merely dip the pieces into the preparation and withdraw them immediately, taking care that all the parts have been wetted with the glaze.

When the earthenware is to be printed it undergoes this process previously to glazing. It is thus performed:-the landscape or pattern is engraved upon copper, and the desired colour being mixed with linseed-oil, is laid on the plate, and impressions are taken off on tissue-paper, in the manner usually employed by copper-plate printers. The paper, wet with the colour, has then all the blank parts cut away, leaving only the pattern entire, which is applied lightly to the ware when in the state of biscuit. It is then rubbed with a piece of woollen cloth, and rolled tightly in the form of a cylinder, till the colour is pressed sufficiently into the ware. In this state the whole is left for an hour, when it is placed in a cistern of water, so that the paper becomes sufficiently moistened to peel off readily, having transferred to the biscuit the colour and impression which it had received from the copper-plate. When the pieces thus printed are sufficiently dry they are placed in an oven and exposed to a gentle heat, in order to dissipate the oil: they are then in a fit state to receive the glaze. Till within the last few years, blue produced from the oxide of cobalt was the only colour employed, but at present many other colours are printed with equal facility.

The art of painting on earthenware more particularly applies to porcelain: the description of the colours used, which are all metallic oxides, and the manner of applying

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produced in the ground. The latter are frequently more than a foot in width, and sometimes water gushes out of them like a fountain.

them, therefore more properly belong to the article under that head, as well as the method of gilding porcelain. Gold and silver lustre ware is commonly of an inferior quality. The metallic oxides used for this purpose are intimately Nothing makes such an awful impression on the senses mixed with some essential oil, and then brushed entirely as an earthquake. The earth is violently convulsed, heaving over the surface of the vessel: the heat of the enamelling up and down in a manner hardly conceivable by those who oven dissipates the oxygen, and restores the oxides to their have not witnessed it. The tottering buildings, the crashing metallic state, but with their brilliancy somewhat diminished. of the timbers of the roofs, and the falling of the tiles, comThe principal seat of the manufacture of earthenware in pletely distract the senses. Fear drives men from their England is in Staffordshire, about a mile from the borders houses; but they do not always find safety out of doors. No of Cheshire. This district, known as The Potteries,' ex-person can stand without support: people cling to one tends through a distance of more than seven miles, in which another, to trees, or to posts. Some throw themselves on there are towns and villages so thickly built and so close the ground; but the motion of the earth is so violent that to each other that to a stranger the whole appears one large they are obliged to stretch out their arms on each side to straggling town. There are likewise extensive manufac- prevent themselves from being tossed over. Animals are tures of earthenware and porcelain in Yorkshire, and equally alarmed. They stand with their legs spread out Worcestershire. There are establishments for making the and their heads down, trembling violently. The air itself commoner kinds of ware in many parts of the kingdom. seems to participate in the convulsion, for the birds fly In the evidence given by Mr. Wedgwood before a com- about wildly. Meanwhile the sea retires from the shore; mittee of the Privy Council in 1785, it is stated that the but after a few minutes it returns in a high wave, which manufacturing part alone in the Potteries and their im- advances like a watery wall with incredible velocity, and mediate vicinity gives bread to 15,000 or 20,000 people; covers all those tracts which are not more than fifty feet above yet this is but a small part when compared with the whole high-water mark. It rushes back with equal velocity. This number of those who depend upon it. A very great num- motion of the sea is repeated as long as the shocks of the ber of persons are employed in raising the raw material earthquake are violent. Vessels sailing along a coast conand the coals for fuel, in the conveyance of these materials vulsed by an earthquake feel also a motion quite different to the Potteries, and in the re-conveyance of the finished from that produced by gales or currents. The loss of life goods to every part of England and to the different ports by earthquakes is sometimes considerable. It is chiefly where they are shipped for foreign consumption. produced by the falling of the buildings when the shock is so unexpected that the inhabitants have not time to escape. In some cases the overflowing of the sea has been fatal to a great number of persons. People have also been swallowed up by the fissures caused by earthquakes.

The number of pieces of earthenware of English manufacture exported, and the real value of the same in each year, from 1831 to 1835, were as follows:

Pieces.

Value.

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1835 45,893,446 540,421

Earthquakes are generally preceded and sometimes attended by a subterraneous noise, which is compared by some to that of a very heavy artillery waggon rolling quickly over a stone pavement at a distance; by others, to the echo of distant thunder in a mountainous country. It is worthy of remark that this noise is sometimes heard without any earthquake taking place, as in 1784 at Guanaxuato, in Mexico, and that it has been as audible in places situated at a con

Shipments of these goods are made to every country with which Great Britain has any trading relations. The exports in 1835 were sent to various quarters in the following pro-siderable distance from the seat of the earthquake as in portions:

Pieces.

Northern Europe, chiefly to Ger

many and the Netherlands

7,214,515

Southern Europe, chiefly Portugal,

Spain, and Italy

3,293,870

Africa

855,695

Asia, chiefly East India Company's territories, islands of the Indian

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£65,716 Considerable changes may be produced on the surface 42,726 of the globe by earthquakes. It is said that by the earth10,160 quake of 1783 in Calabria some mountains changed their relative positions to one another; but this fact is not well established. It is, however, beyond all doubt that the 30,563 coast of Chile has undergone a considerable change by 246,220 earthquakes during the last fifteen years. In 1822 the coast, north of Valparaiso, to the extent of fifty miles, was raised 6,706,156 74,183 nearly three feet above its former level; in some places the 5,369,103 42,123 rocks on the shore were raised four feet. In 1825 the island of S. Maria (near 37° S. lat.) was upheaved nine feet, so 2,059,943 24,537 that the southern port of this island has almost been de332,082 4,193 stroyed, and the soundings round the island have diminished a fathom and a half every where. Pieces 45,893,446 £540,421 EARTHQUAKES are the most terrific of all natural phænomena. The solid surface of the globe is put in motion by them, and assumes an appearance which in some cases may be compared with the sea when agitated by the

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The least dangerous of these phænomena are those which by the Creoles of South America are called Tremblores, a term which may be translated by tremors. The surface of the earth is put in a trembling motion, by which such objects as are not well supported are thrown to the ground, and even walls are split, but the damage does not extend farther. Life is safe, and property but slightly injured. These tremors are by far the most common kind of earthquakes, and occur in some countries of South America, especially in Chile, almost every day, at least in certain seasons. The terremotos of the Creoles, or proper earthquakes, give to the surface either horizontal oscillations, not dissimilar to the waves of an agitated sea, or they consist in violent perpendicular upliftings, so that it would seem as if repeated explosions were exerting their force against the roof of a subterraneous cavern, threatening to burst it open and to blow into the air every thing placed over it. By these earthquakes walls are overthrown, and fissures are

The single shocks of an earthquake last from a few seconds to two or three minutes. Sometimes they follow one another at short intervals. It is remarkable that generally either the first or one of the first shocks is the most violent, and that they afterwards gradually decrease in force. Sometimes they return for several days, and even weeks; and in some places, as at Copiapò, in Chile, they are of daily occurrence.

Earthquakes are sometimes experienced over an immense tract of country. The last earthquake in Chile (in 1835) was felt at all places between the Island of Chiloe (40° S. lat.) and Copiapò (27° S. lat.); consequently over thirteen degrees of latitude. It extended from the Ísland of Juan Fernandez to the town of Mendoza, on the east side of the range of the Andes, over ten degrees of longitude. But when earthquakes extend over such an immense tract of country, some districts are always convulsed with greater violence, and these may be considered as the centre of the earthquake. The farther a place is removed from these centres, the less violent, as a general rule, are the shocks.

We know little, or rather nothing, of the origin or cause of earthquakes. It may, however, be considered as certain that they are due to the same agency which produces volcanic eruptions. These eruptions are frequently preceded

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