He took the name of Varius from Sextus Varius Marcellus, weights are small, this extension is proportional to the who was his mother's husband. increase of tension. The apparatus is that employed by S'gravesande. ELAM. [ELYMAIS.] ELAPS. [VIPERIDE.] ELASMOTHE'RIUM. [PACHYDERMATA.] ELASTICITY (λaorns, a spring). When the form of a body is affected by the pressure of another extraneous to it, the re-acting force by which it sustains or tends to remove that pressure is its elasticity. The term has been very loosely used in the most current works, which, instead of furnishing an exact and general idea of this force, are, in general, limited to the phenomena exhibited by elastic solid bodies; and to this imperfect notion of elastic force we are to attribute the discrepancies of treatises, some of which used to represent water as perfectly inelastic, some (as the more modern treatises) as perfectly elastic. The cause of elasticity then belongs to the theory of molecularity, its effects in aggregate masses to mechanics. The equilibrium of the molecules of solid bodies is almost completely dependent on their own mutual actions and quantity of heat. These forces determine certain mean places for the constituent particles, to which points of stable equilibrium they tend to return when removed a little from them by an external force. This removal may be such as to effect in the mass either compression or extension, inflexion or torsion, and therefore their elastie foree is capable of being exhibited in all these ways. It is demonstrated in fluids only by their compressibility, while in gases it arises as a predominant living force which would refuse any position of equilibrium to the constituent particles without external pressure, and is proportional to such pressure uniformly exercised. When a uniform elastic string is suspended vertically it will be stretched by its own weight. The tension varies from point to point, and is every where proportional to the portion of the string of which it supports the weight. If y be When heat is applied to a solid elastic body, that is, when a portion of the stretched string corresponding to a portion its temperature is raised, the particles seek a different posi-a of the same unstretched, and y + ▲ y, x +▲r, another tion of equilibrium more remote from each other than corresponding pair of portions greater than the former, and before. But while this heat is much below that necessary a the whole length of the string in its natural state, the for friction, or for destroying the fibrous formation of organ- extension Ay-Ax of the element Ax is proportional to ized matter, the stability of the removable particles is but the weight of the remaining portion a-x-Ax of the little affected, and experiment shows that there is scarcely string; hence if g denote the weight of a unit of the string, any change of elasticity. In fluids the compressibility obtains and the index of elasticity peculiar to the substance, we a greater range, while in gases, where no countervailing dy force of attraction is sensible, the increase of temperature is have ultimately [DIFFERENTIAL CALCULUS] 1accompanied by a proportional increase of elastic force. ge(a-x), and therefore by the rules of the Integral Calculus X2 y - x = ge (ax -), to which no arbitrary constant need be added, because y commences at the same point with : if we now make x = a, we find that g .as expresses the extension of the entire string. Amongst bodies whose elasticity is very apparent, we may enumerate glass, ivory, caoutchouc, sponges, and fibrous substances, as beams, muscles, and artificial webs, some gums, steel, and all the gases and vapours. In gases and vapours its effects may be produced to any extent, but they are limited in solids by their softness and facility of fusion, as in wax, lead, &c.; by their absorption of moisture, as in elay, feathers, catgut, straw; or by their friability, as in glass, dry resins, and copper or iron which have been exposed to a stream of ammoniacal gas. 2 e 2 dx Similar principles may be easily applied to determine the form of an elastic string suspended from two points, and stretched by its own weight; but in this case the curve which differs from the common catenary cannot be considered as accurately determined without taking into account the elasticity of inflexion as well as that of extension. The mere mathematical problem may be seen in most mechanical treatises. (Whewell's Mechanics; Poisson, Mécanique; consult also Lagrange, Mec. Analytique, for the method of introducing the condition of elasticity in a system at rest.) An important practical branch of this subject, on the strength of beams, which has been much advanced by Mr. Peter Barlow, and the more recent experiments of Mr. Eaton Hodgkinson, of Manchester, we reserve for a future article. [STRENGth of Beams.] Suppose an elastic string, or lamina, to be fixed at one end, and at the other stretched by a force T, which will also represent its tension; if this force be increased by a small quantity t, an additional length I would be given to the string, or lamina; the whole tension now is T+t, and if we again add a force t, since the physical condition of the body is sensibly the same as before, the same length / will again be added, and generally the additional extension should be proportional to the additional tension: this law is, however, only approximative, for it is manifest that a force tending to produce either extension or contraction may be applied which would cause the body to break, and near these limits the law would vary considerably from When a uniform elastic string, fixed at one extremity simple proportionality. Let a horizontal elastic lamina AB and stretched by a force applied at the other extremity, is be fixed by a screw at A, and having been stretched by a abandoned to itself, it will return to its original form after known weight G at B, let it be screwed also at that point, a series of contractions and expansions, the force which when its tension will evidently be equal to the weight ap- solicits each point being proportional to its distance from pended; let the beam DE of a balance F be sustained at D, its original place, though the successive oscillations go the middle of AB through a drilled orifice d, and be at- on rapidly diminishing in extent in consequence of the retached to a string passing over the fixed pulley C, which sistances encountered. The same law applies to the disstring also sustains a weight P, which is an exact counter-placements of the molecules of elastic fluids and gases. poise to the weight of the scale and beam so that they may For the laws of the mutual impact of elastic bodies see produce no deflection of themselves in AB; then if a small IMPACT. If a body is attached to an elastic string, which weight be put into the scale, the lamina ADB will be bent at the other extremity is fixed, and be projected in any into the form AdB, with a deflection Dd from its original direction, the resolved part of the centrifugal force which position, which may be estimated with greater accuracy by acts in the direction of the length of the string tends to a hand QR attached to the pulley. An extension AɗB – stretch it, and the centripetal force will be proportional to ADB will thus be produced, as well as an increase of ten-re, r being the length of the stretched and c of the sion, which may then be compared by the common laws of unstretched string: this force is attractive when r is greater statics; and the experiments show that as long as the added than e, and repulsive when less. Hence if we conceive a circle, of which the centre is the fixed point, and the radius equal to c, the portions of the orbit described externally to the circle are concave, and those internally are convex relative to the centre of the circle, and there are as many points of contrary flexion [CURVE] as intersections of the trajectory and circle. Neither the law of the periodic times nor the form of the orbit is similar to those belonging to the earth and planets: the supposition, therefore, that attraction between the great masses which compose the solar system is conducted through the medium of interposed and invisible elastic strings is unfounded. When an elastic string, fixed at one end is bent by a weight or other force applied at a given point, the elasticity of inflexion acts normally at each point of the curve, and is some function of the curvature at that point. It is usual to suppose it proportional to the simple curvature. On this supposition the figure of an elastic lamina in a vertical position, fixed at its lower point and bent by a small weight applied at the top, may be determined. This problem has been treated by Euler, Lagrange, and Poisson. The English reader may find the varieties of the elastic curve discussed in the appendix to Whewell's Mechanics. The elastic force of a twisted string follows a law precisely similar to that of one which is only stretched: the latter is proportional to the extension, the former to the torsion. Thus, if a cylindrical elastic thread, fixed at one extremity, be twisted by a force applied perpendicularly to its length, any straight line taken along the surface of the cylinder will be converted into a helix; and with a double torsion the circular arc through which each point has been removed from its original place is doubled. And since the circular arc may be subdivided into any number of equal arcs, the successive resistances of the elasticity to the additional torsions are equal, supposing each preceding resistance to be sustained. Therefore the accumulated force of torsion is proportional to the angle through which an index would move if fixed at any point perpendicularly to the length of the cylinder, or in the prolongation of its radius. but this law has limits as well as that for the elasticity of extension; for the torsion may be continued until a strain is produced, when there will of course be an accompanying diminution of elastic force. Let A B represent an elastic string, suspended vertically G B A E cylinder, perpendicularly to the radius, the constant n signs; and since d t2 δ d Ꮎ is the common accelerating force on all the particles dm at a unit distance, we need only take the sum of the products rm, which is easily found in this case by the rules of the integral calculus, and is called the moment of inertia of the cylinder. Representing it by M K, where M is the mass of the cylinder and K its radius of gyration, we have the equation— dt was Now, we can determine the constants by the circumstances of the origin of the motion; for when t = 0, we have d Ꮻ supposed the initial torsion was a, or FBC, and then nothing. Hence we have a = A sin. B; o=A cos. B: π The value of is therefore extherefore A2=a3, B= 2' pressed at any time by a cos. (ct). When the cylinder makes half an oscillation the elastic thread is then perfectly free from torsion; and if T be the time of an entire oscillation, since 0 then vanishes, we find that the successive oscillations are of the same duration, and that the square of the time of one oscillation varies directly as the moment of inertia, and inversely as the force of torsion, estimated at a given distance from the string. The suspended body may be any other as well as the cylinder we have supposed, with manifestly the same results. For instance, in Coulomb's torsion balance it consists of a needle of gum-lac attached perpendicularly to the string, as BF in the above figure, and a small weight at B to steady the string; the law of the times of oscillation above found is sufficient to give the force of torsion in all cases if we know it in one. It is thus that Coulomb used his balance in finding the law of electrical attractions and repulsions; the electrised ball acted on, being attached to the end of the needle of gum-lac, was subjected to the joint action of electrical and elastic forces. [ELECTRICITY.] from the point A, and attached at B to a cylindrical body of their great resistance to compression, is extremely The range of the elastic force of fluids, in consequence DE, of which the axis BC is in the direction of the string limited, and therefore few ordinary phænomena of nature produced, the string being primitively in an untwisted state. Let the cylinder be turned round its axis through siderable depths in the ocean must produce a corresponding are dependent on this cause. The great pressure at conan angle FBG, or a, which measures the torsion generated increase of density in the lower strata, if it is not in a great in AB, and also the elastic force tending to bring the sys-measure compensated by the increase of temperature. tem back to its original state. Let the restraining force be now removed, and the cylinder, abandoned to itself, will return to its original place after a series of isochronous oscillations, which are gradually diminished by the resistance of the air and by the internal resistances of the molecules of AB during the processes of being twisted and untwisted. Let &m stand for an element of the cylinder, situated at a distance r from its axis, and 0 the angle of torsion, at the elastic force of gases: or, which is the same, under a But an increase of temperature produces an increase of time after the commencement of this motion; then d Ꮎ given pressure it expands the gas into a greater volume. is the angular velocity; and therefore the linear velocity this increase of volume is proportional sensibly to the addidt Between the temperature of melting ice and boiling water of mis-r? ; the accelerating force or ratio of the in-us was well established by the experiments of Gay-Lussac tional temperature, measured by a mercurial thermometer, but by the more recent experiments of MM. Dulong and degrees of the mercurial and gas thermometers no longer Petit, it appears that at much higher temperatures the correspond; for the expansions of the mercury might be de dt d Ꮎ any crements of velocity and time is -r; the force of torsion, being proportional to the angle e, may be represented by no applied at a distance unity from the axis of the There exists one simple and uniform law for the elastic forces of dry air and all the gases. From the experiments of Boyle, Mariotte, and Dalton, it is established, that the elasticity, which is proportional to the pressure, is inversely as the volume, and therefore directly as the density, when the temperature is constant. expected to become irregular when it tends to gaseify, and In such experiments it is essential that the gas should be perfectly dry; for if not, the elastic force obtained will be that of dry air plus that of the contained aqueous vapours. For most observations on the latter we are indebted to the researches of Dalton, who observed that when the inside of a barometer is moistened, the elastic force of the vapours, occupying the space which is a vacuum in ordinary barometers, causes a depression in the column of mercury proportional to itself. When a space is saturated with aqueous vapour or steam, the elasticity remains the same when the volume is diminished, the only effect of compression being to convert the surplus portion into water. The contrary holds generally in gases, as we have seen that their elasticity is inversely as their volume; but it is probable that with very high pressures, such as that employed by Mr. Faraday to liquefy carbonic acid gas, there exists a limit for each, beyond which it is impossible to render them more elastic by compression. Moreover, the ratio of the elastic force of dry gas at the temperature of boiling water to that at the freezing point is by no means the same as in aqueous vapours; but at very high temperatures it seems probable that similar ratios would approximate. The following is a table of the elastic forces of the latter, corresponding to degrees of the centigrade thermometer: The third column is given incorrectly in Biot's Physique; and it follows from inspection that the elastic force of steam increases nearly in a geometrical progression when the temperature is increased in arithmetical; from which property steam has now become a great mechanical agent. When vapours are mixed with each other at the same temperature and in the same space, the elastic force of the compound is the sum of the separate elasticities, provided this sum is not sufficiently great to render any of the vapours liquid, and provided these vapours have no chemical affinity. The vibrations of elastic bodies belong to the subject of acoustics, to which we refer, and to the head VIBRATION. Beside the authorities already quoted in this article, see Pouillet, Physique,' and Manchester Transactions.' ELATEA. [PHOCIS.] ELATE'RIDE, a family of Coleopterous insects belonging to the section Sternoxi (Latreille), and, according to Linnæus, constituting the Elater. genus The insects of this family are of a lengthened form; the head is, in nearly all cases, deeply inserted into the thorax: the thorax is usually of the same width as the elytra, or nearly so, longer than broad, and the posterior angles are acute, and most frequently produced into a pointed spinelike process: the elytra are long and narrow, cover the abdomen, and their external margins are often nearly parallel. The antennæ are of moderate length, either filiform, serrated, or pectinated, and when the insect is at rest they are deposited in two grooves on the under side of the thorax; at least such is the case in very many of the species. The legs are short and rather slender, and the femora and tibiæ are generally compressed. These beetles are found upon flowers and upon the leaves of trees and plants; some species however are most frequently met with upon the ground. When upon any elevated situation, if approached, they apply the legs and antennæ close to the body, and allow themselves to fall to the ground; if they fall upon their back they regain their natural position by a leap, which is always accompanied by a snapping noise similar to that which may be made by the finger-nails. When about to leap, they bend the thorax backwards, so that the body is arched, or rather forms an angle, the insect then resting upon the apex of the abdomen and the fore part of the thorax. The leap appears to be effected by the sudden relaxation of the muscular effort which kept the thorax bent backwards, there being a peculiarity in its structure which causes it to spring forwards. Even in a dried specimen, upon attempting to bend the thorax back, we found considerable resistance; but when allowed, it suddenly assumed its natural position, which is a slight inclination forwards. There is a strong spine, it must be observed, on the under part of the thorax, at its base, which, when the thorax is in its usual position, is deposited in a groove; and it is said that the leap is performed principally by means of this spine, which is at the time forcibly pressed against the margin of the hollow into which it sinks suddenly, as if by a spring. From this opinion we are inclined to differ; for upon removing the spine we found not the slightest alteration in that natural spring in the thorax which we before mentioned. Not however having at this moment the means of investigating the subject, it would be premature to venture any further remarks. The larvæ of the Elateridae feed most generally upon vegetable substances: rotten wood affords food to many; others live in the ground, and feed upon the roots of plants: one of them (the larva of Elater striatus of Fabricius) is said to attack the roots of the wheat, and when in great numbers, to do much injury*. These larvæ are long, rather slender, generally cylindrical, and covered with a tough skin: the head and terminal joint of the body are of a corneous texture; the latter is very variable in form, and is often depressed and produced into two bluntly-pointed processes: the former is furnished with the usual parts, such as jaws or mandibles, maxillæ, palpi, labrum, labium, and antennæ. The three segments which constitute the thorax are each furnished with a pair of short legs. Of the insects included by Linnæus under the generic name of Elater, and others of similar general characters which have been discovered since that naturalist's time, there are upwards of five hundred species enumerated, and as these species (which are now regarded as constituting a family) are divided into about sixty genera, it will be impossible, consistent with the plan of this Cyclopædia, to enter into the detail of their characters. We will therefore confine ourselves to some of the more important;-in fact to those which are given by Latreille in the Règne Animal:' these are as follows:-Galba, Eucnemis, Adelocera, Lissomus, Chelonarium, Throscus, Cerophytum, Cryptostoma, Nematodes, Hemeripus, Stenicera, Elater (proper), and Camphylus. These genera are divided by Latreille into two sections, in the first of which the antennæ are lodged (when the insect is at rest) within two grooves situated on the under side of the thorax. The genus This section includes the six first genera. The species are all from Brazil. The genus Eucnemis Genus Adelocera (Latreille). Here the antennæ are filiform; the joints of the tarsi are simple, and the anterior legs, when contracted, are received into lateral cavities in the under part of the thorax. Lissomus (Dalman.) The species of this genus have A larva of one of the Elaterid (which there were good reasons for believing was that of Elater æneus) we have found more than once feeding upon worms. 1 little cushion-like lobes on the under side of each joint of the tarsi. In the genus Chelonarium (Fabricius) the form approaches to an oval, the second and third joints of the antennæ are larger than the following and of a flattened form, and these alone are received into the sternal grooves. The head is almost hidden by the thorax, which is semicircular, and the anterior legs are larger than the rest. All the species are from South America. Genus Throscus (Latreille). This genus is readily distinguished by the antennæ being terminated by a treejointed knob the penultimate joint of each tarsus is bifid; the mandibles are simple. The species of Throscus are very minute. Throscus dermestoides, an insect not uncommon in this country, is about one-eighth of an inch in length, of a brown colour, and obscurely covered with an ashy pubescence. The second section of the Elateridæ comprises those species in which the antennæ are free, or not lodged within grooves on the under part of the thorax. Cerophytum (Latreille). The principal characters of this genus are: terminal joint of the palpi larger than the following, and almost securiform; tarsi with the four basal joints short and triangular, the penultimate joint bilobed; antennæ serrated in the female, and in the male branched internally. The Cerophytum Elateroides (Latreille), an European species, affords an example of this genus. Cryptostoma (Dejean). Tarsi simple, small, and slender; anterior extremity of the præsternum projecting beneath the head; the apex of the third and seven following joints of the antennæ prolonged; mandibles unidentate; maxillæ with a single lobe; palpi very short. Cryptostoma denticornis (Lat.), the only species known, is from Cayenne. Nematodes (Latreille). Body nearly linear; antennæ with the basal joint elongated; each of the five following joints in the form of a reversed cone; the remaining joints almost perfoliate, with the exception of the last, which is oval. Species of this genus have been found in Europe and North America. Hemerhipus (Latreille). In this genus the parts of the mouth are exposed, i. e., not as in the two last genera, hidden by the projecting process of the præsternum; the antennæ are flabellate at the apex in the males. All the species of this genus are extra-European. In the genus Ctenicera (Latreille) the antennæ are pectinated in the males, and deeply serrated in the females. The Ctenicera pectincarnis, an insect common in some parts of this country, affords an example of this genus. This species is rather more than half an inch in length, and of a brilliant metallic green or copper-like colour: the female is larger and broader than the male. truded from the thorax: the antennæ are inserted beneath a frontal projection on each side, and the body is long and almost linear. One species of this genus is found in England, the Campylis dispar, which is of a yellowish colour. In some specimens the head, legs, and antennæ are black, and sometimes the elytra are black with a broad pale margin. ELATE'RIUM. [MOMORDICA.] ELATMA or YELATMA, the chief town of the most northerly circle in the Russian government of Tambof in Great Russia. It is situated at the confluence of the Myksha and Oka, on the left bank of the latter, in 55° 5' N. lat., and 42° 34′ E. long. Elatma is an old town, and contains ten churches, eight of wood and two of stone, several government buildings, about 800 houses and thirty-four wooden stores, and about 6000 inhabitants. It has manufactures of linens, vitriol, and sulphur, and a considerable trade in grain, hemp, wax, and honey, chiefly with Moscow, and the provinces on the banks of the Volga, to which parts the Oka gives the means of ready access. The extensive iron works of Yeremshink, which employ nearly a thousand hands, are in its immediate neighbourhood. ELBA, the Ilva of the Romans, called Athalia (Alaλía) by Strabo, p. 223, is an island in the Mediterranean sea, near the coast of Tuscany, and divided from it by the channel of Piombino, which is about five miles broad in its narrowest part opposite the town of Piombino, which lies on the main land. The shape of Elba is very irregular; its length is about eighteen miles, from 10° 6' to 10° 25' E. long., and its greatest breadth, which is on its east side, is about ten miles, from Cape Calamita 42° 43' to Cape Vito 42° 52′ N. lat.; but in its west part it is six miles broad, and towards the middle of its length it is only three, owing to the coast being indented by gulfs both from the north and south. Its area is about 154 square miles. The island is mountainous; the highest summit, Monte della Capanna, in its west part, is 3600 feet above the sea. The mountains are mostly naked, but the lower ridges and the valleys between are planted with the vine, olive, and mulberry, and other fruit trees. The island produces also some wheat and Indian corn, vegetables, and water melons. Wine, both white and red, is made in considerable quantities; some of it, especially the red sort, is very good, and forms an article of exportation. There is also a kind of muscadel, or dessert wine. Horned cattle and horses are rather scarce, but there are plenty of sheep, goats, pigs, and asses. the tunny fishery yields a considerable profit. The salt Fish is plentiful on the coast, and pans on the sea-shore produce about 50,000 cwts. of salt yearly. Elba is rich in iron, which is of the best quality, and was worked in the time of the Romans. a mountain, near Rio on the east coast, which is almost enIt is found in tirely a mass of ore, about two miles in circumference, and and the ore yields from 50 to 75 per cent. of pure metal. 500 feet in height. About 120 miners are employed in it, to the mainland to be smelted, as it was when Strabo wrote. Owing to the scarcity of fuel the ore is embarked and taken The annual quantity of metal raised is about 40,000 cwts. The other mineral productions of Elba are loadstone, alum, vitriol, and marble of various kinds. The population of Elba is about 13,500, of which Porto Ferrajo, the capital, has about 3000. Porto Ferrajo lies on the north coast of the island, and is strongly fortified with two citadels on the hill above it, churches, one hospital, and a lazzaretto. It is the residence and has an excellent harbour. The town has two parish of the cancelliere, or political governor for the whole island, which is included in the province of Pisa; it has a garrison and military commander, a civil and criminal court, from which appeals are laid before the ruota, or high court of Grosseto. From Porto Ferrajo a good road, five miles in length, made by Napoleon, leads to Porto Longone on the east coast for vessels. The castle of Porto Longone is on a steep hill, of the island, on a deep bay, where there is good anchorage and is regularly fortified. The town or village is small, and reckons about 1000 inhabitants. The other principal villages in the island are Rio, Marciana, Campo, and Capo Liveri. The, island of Elba has acquired considerable ceIn the genus Campylus (Fischer) the eyes are more pro-dence of Napoleon after his first abdication, from May, lebrity in our times, on account of it having been the resiminent than in the other Elateride, and the head is pro- 1814, to the 26th of February, 1815, when he set sail for Other insects having the same power of emitting a light by night are duchy of Tuscany. The mountains of Elba form a conspiCannes. From that time it has been annexed to the grand cuous object as seen from Leghorn, which is about fifty VOL. IX.-2 U In the genus Elater, as now restricted, the antennæ are simply serrated. The Elater aneus of Linnæus will serve to illustrate this genus. This species, which is common in some parts of England, is generally found under stones on hills of but little elevation, and which are more or less covered with heath. It is about three quarters of an inch in length, and most commonly of a brilliant green colour; some specimens however are blue, and others are of a brassy or bronze bue. The Elater noctilucus, according to Latreille, also belongs to this genus. This species is well known in South America, where it is called the fire-fly.* It is rather more than an inch in length, of a brown colour, and covered with an ashy down on each side of the thorax there is a round glossy yellow spot. These spots emit by night a light so brilliant as to enable a person to read by it, and it is a common practice to place several of the insects together in a glass jar or bottle for this purpose. This insect (with upwards of twenty other species, all of which emit light by night) is now included in Illiger's genus Pyrophorus. The species of this genus are, some of them, from each of the following localities:-Brazil, Peru, Buenos Ayres, Chile, Cuba, St. Domingo, and Guiana. undoubtedly confounded with the present species under the name of the fire-fly. P. C., No. 572 miles north of the nearest point of the island. (Neigebaur, I comes navigable for large ships. Its mouth lies north of Gemälde Italiens; Pini, Osservazione sulle Miniera di Cuxhaven, about 85 miles below Hamburg. Ferro dell' Isola dell' Elba.) The Elbe first flows through a deep narrow valley to Josephstadt, the right bank being much higher than the left. This valley widens gradually until the Elbe has passed Nimburg, between Kollin and Brandeis, where it again be comes contracted. From Nimburg to Raudnitz, south of Theresienstadt its banks are lower, but from the last town until it reaches Lowositz they are much more elevated, and thence, as far as to Pirna in Saxony its bed lies in a deep confined valley. From Pirna the heights on its left bank subside, whilst those on its right accompany the Elbe at a little distance until it has passed Dresden and Meissen. From thence to Torgau a succession of low hills run parallel to both banks, and there entirely disappear. A range of hills approaches the left bank at Dömitz, and occasional heights the right bank near Wittenberg. From the mouth of the Saale until a little above Magdeburg the banks are flat, but in this part high hills command them at several points. From Magdeburg the Elbe flows through a level Bleckede on its left and about Altona on its right bank, where the adjacent ground rises to gentle elevations. In the lower parts of its course, namely, between Harburg on its left bank, and Hamburg and Altona on its right, the Elbe is divided into several arms by five large and seven small islands; these arms, however, unite again in a single channel at Blankenese, about five miles below Hamburg. The whole length of the Elbe is about 710 miles, and it is navigable for about 470 miles. Its mean depth is 10 feet and its average breadth 900 feet, but it widens at some points to 1000 feet and more, and near its mouth to several miles. The height of this river above the level of the sea is as follows: near its source 4151 feet; at Königsgrätz 618; at Melnik 426; at Schandau 320; at Pirna 287; at Dresden 262; at Wittenberg 204; at Magdeburg 128; at Tangermünde 87; at Losenrade 48; at Dömitz 26; at Hitzacker 19; at Bieckede 11, and at Boitzenburg 9 feet. ELBE, The, one of the largest rivers in Europe, flows like the Weser entirely within Germany. It originates in the confluence of a number of rivulets and brooks which fall down the western side of the Schneekoppe, or Snowcap, one of the highest mountains in the Riesengebirge, or Giant mountains, of Bohemia, and in that part of them which separates Bohemia from Silesia. Some writers refer the source of this river to the Weissbach (Whitebrook), which springs from the White Meadow, at the foot of the Schneekoppe; others to the Elbe or Narvor Meadow, where eleven springs, called the Wells of the Elbe, are said to rise, and uniting in one stream, which takes the name of the Elbe or Mädelbrunn, fall over a lofty precipice into what is termed the Elbgrund, or region of the Elbe. Here the stream is increased by the Seifen and other rivulets which join it below Krausensbaude, whence it runs towards Hohenelbe under the universally admitted designation of the Elbe. From Hohenelbe, a mountain town in the north-country into the North Sea, except between Hitzacker and eastern circle of Bidschow, in Bohemia, it flows south-east to Arnau, thence south-west into the circle of Königsgrätz, where it is joined by the Aupa near Yarowitz, the Metau at Josephstadt, and the Adler or Orlitz at Königsgrätz, and afterwards passes into the circle of Chrudim, whence, after receiving the Chrudimka at Pardubitz, it takes a westerly direction. Having passed Elbe-Teinitz, below which it is joined by the Dobrowa, and skirting the northern extremity of the circle of Czaslau, it traverses the most north-eastern part of that of Kaurzim, where it flows past Kolin, and there winding to the north-west re-enters the circle of Bidschow, and crosses its south-westerly districts past Podicbrad. It now pursues a course due west along the southern border of the circle of Bunzlau, re-enters that of Kaurzim, flows north-west from Taurzim past Brandeis, above which it receives the Iser and Elbe-Kostoletz, to Melnik, in the south-western extremity of the circle of Bunzlau, where it is increased by the waters of the Moldau, and from which place (in 50° 20' N. lat. and 14° 28′ E. long.) it has an unobstructed navigation to its mouth. From Melnik it forms the boundary for a short distance between the circles of Rakonitz and Leitmeritz, then winds southwards to Kaunnitz, and after entering the last-mentioned circle by again flowing north-westwards from Kaunnitz, is joined by the Eger a few miles above the town of Leitmeritz. From this place it flows northwards to Aussig, takes a winding easterly course past Tetschen where it receives the Pulznitz, bends gradually north-westwards, quits Bohemia near Hernkretschen, or Hirniskretschen, and enters the kingdom of Saxony. At this point the Elbe is 355 feet in width. It thence takes a north-westerly course past Schandau, between which place and Dresden it passes through the Lusatian and Ohre Mountains of Saxony, then flows to Pirna, Dresden, Meissen, Riesa, and Strehla, and enters Prussian Saxony at Loesnitz, about seven miles above Mühlberg. Its whole length from the south-eastern to the northern frontiers of Saxony is between 70 and 75 miles. From Mühlberg its course is north-westerly to Torgau, and thence to Wittenberg, above which it receives the Black Elster; here it takes a westerly direction, leaves for a while the Prussian states, traverses the Duchy of Anhalt from Koswig ELBERFELD, a circle in the eastern part of the county past Dessau to Barby, during its passage through which it or administrative circle of Düsseldorf in the Prussian proreceives the Saale and Mulde, and thence turning north- vince of the Rhine. It contains an area of about 125 wards, re-enters those states above Aacken, receives the Ohre, square miles, three towns (Elberfeld, Gemarke or BARMEN, and flows on to Magdeburg until it reaches the point be- and Mettmann, with about 2100 inhabitants), one marketlow Sandow, where it is joined by the Havel. Here it again village, 21 villages, and 135 hamlets, and has a population of has a north-westerly direction, forming first the boundary about 93,500; which is an increase of 22,750 since the year between Brandenburg and Prussian Saxony till it passes 1816. About one-fifth are Roman Catholics, and the Schneckendorf, and next for a short distance between Bran- remainder Protestants. The circle is traversed in all parts denburg and Hanover: thence it separates Hanover from by offsets of the Sauerland hills, and is well wooded. ExMecklenburg until it enters the north-eastern districts of tensive beds of alum lie between Velbert and Langenberg that kingdom between Dömitz and Hitzacker. After tra- in the northern part of the circle, where a number of alum versing them as far as Boitzenburg, it divides the Hano- works are established. Elberfeld is watered by the Ruhr, verian dominions from the duchies of Lauenburg and Hol- Wipper or Wupper, Düssel, and 26 minor streams and stein and the Hamburg territory, until it discharges itself brooks. The soil is in general but of middling quality into the North Sea. Altogether it traverses Hanover or some of the more elevated districts it is light, and calcu forms its north-eastern boundary for about 120 miles. Be-lated for the cultivation of rye, oats, and potatoes only low Winsen, which lies to the south-east of Harburg in In the others, wheat, rye, barley, oats, peas, and flax are Hanover, the Ilmenau falls into it, and below Neuhauss raised. There are excellent meadow and grazing lands. somewhat above Altona, but on the left bank like the for- The vicinities of Elberfeld, Barmen, Hardenberg, and Kron mer, the Oste. From Hamburg and Altona downwards to enberg are crowded with manufactories of cotton yarn Glückstadt in Holstein and thence to the North Sea it be- and cloths, silks, woollens, linens, ribbons, lace, velvets, There are 35 bridges across the Elbe between its source and Torgau, below which town the communication between both banks is by ferries. The principal bridges are those at Leitmeritz, which is of wood and stone, and 823 feet in length; Brandeis; Dresden, of stone, 1420 feet long and 36 broad; Meissen; Torgau; Wittenberg, of stone and wood, 1000 feet long; and Magdeburg, where there are three wooden bridges, one across the Old Elbe 76 roods long; another across the main arm of the river, 24 roods; and the third across a side arm 20 roods long. The waters of the Elbe are increased by the confluence of 17 rivers and upwards of 70 minor streams. Between the years 1801 and 1835 its depth has decreased nearly 8 inches at Dresden, and about 18 at Magdeburg. In Bohemia, where less attention has been paid the clearing of woodlands and drainage of swamps and marshes than in the territories through which the Saale, Mulde, and Black Elster flow, the diminution has been far less. The basin is estimated to occupy about 58,800 miles, and lies between 50° 2′ and 53° 54' N. lat., and 8° 41' and 16° 12' E. long. This river is well stocked with fish, particularly salmon, eels, and sturgeons. |