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αγαθος becomes αγαθον to agree with ανδρα, and αγαθην to 3. Πελοπι from Πελου, Πελοπος, 8 proper name, governed agree with yuvaika.. Compare the declensions of adjectives in the dative case by noav; to Pelops there were, that is, and nouns combined in the fourth and sixth lesson.
Pelops had; Ατρευς (g. εως), Atreus; θυεστης (g. ου), Thyestes. As a general rule, a transitive verb, or a verb which has an Observe that the English y represents the Greek v. object after it, has that object in the accusative case, as in the 4. παρ' for παρα, against, παρ' ελπιδα, contrary to their expecsentence just given-ανδρα αγαθον θαυμαζω. Many verbs, how-tations ; ελπιδα, acc. sing. from η ελπις (g. ελπιδος), hope ; ever, put their object in some other case; some require the geni- why has the plural adjective olla the verb in the singular ? tive, and some the dative. Examples have already appeared. When two nouns come together in a state of dependence from xovorov, a diminutive of xpvoos, gold, and so denoting
6. τροπος, ου, ο, 8 turning, disposition και χρήσια, neut., pl., the dependent noun is put in the genitive case: e.g., 041E5-golden ornaments, jewels. ανδρος του Φιλιππου ην υιος, Alexander was the son of Philips where Pilet tov is in the genitive case because it is in sense
6. τεττιγες, grasshoppert, from o τεττιξ (g. πττίγος) ; ευφωνοι, dependent on vios.
pleasing in sound, nom. pl., from evowvos (ev and owin, a When two verbs come together in a state of dependence, the third person plural, passive voice, present tense, from heyw,
voice), an adjective of two terminations ; leyovrai, are said, the dependent verb is put in the infinitive mood: 1.8., I say; it governs avai, to be, in the infinitive mood. βουλομαι υδωρ πινέιν, I wish to drink water; where πινειν 18 governed in the infinitive mood by Boulouai, the former being
7. μυρμηκων, gen. pl. governed by βιος, from o μυρμης, in sense dependent on the latter.
μυρμηκος, αη ant; μελισσων, gen. pl. governed by βιος, from
μελισσα, ης, η, ο δδε και πολυπονος, ον (from πολυς and πονος), RECAPITULATORY EXERCISES FROM THE GREEK CLASSICS. laborious. 1. Μια χελιδων εαρ ου ποιει. 2. Παντα ο χρονος προς φως
8. γιγνωσκει (from γιγνωσκω, I know), indicative mood, active άγει.
3. Πελοπι υιοι ησαν Ατρευς και θυεστης. 4. Πολλα voice, third person singular agreeing with its subject, or ανθρωποις παρ' ελπιδα γιγνεται. 5. Γυναιξι κοσμος ο τροπος
nominative φωρο φωρ, φωρος, o, a thiefs λυκος, ου, ο, α wolf. (sc εστιν) ου τα χρυσια. 6. Οι τεττιγες ευφωνοι λεγονται
9. χρησις, εως, ή, κος και οργανον, ου, το, 4 means, our organ. 7. Μυρμηκων και μελισσων βιος πολυπονος εστι. 8.
10. ανευ, without ; τυφλον, from τυφλος, η, ον, διnd; the
adjective is in the neuter gender, denoting disparagement, a Γιγνωσκει φωρ τον φωρα και λυκος λυκον. 9. Ου κτησις αλλ' η δίind thing; διχα, separate from; ελλιπες, from ελλιπης, ες, χρησις των βιβλιων οργανον της παιδειας εστιν. 10. Η μεν | defective (from λειπω, I leave). φυσις ανευ μαθησεως τυφλον, ή δε μαθησις διχα φυσεως ελλιπες. 11. προστιθει, αdds, from προστιθημι, Ι αα και επιστημη, ης, ή, 11. Ο χρονος τω γηρα προστιθει την επιστημην. 12. Πολλα. | understanding. ησαν αι της βουκερω Ιούς πλαναι. 13. Ανης ανδρα και πολις | that from βόυς and κερα; Ιους, Io, from Iω, ούς, πλαναι, wan
12. βουκερω, λανίng the horns of an ow, from βουκερως, ω, and πολιν σωζει. 14. Επαμεινωνδας ως αληθως εν ανδρασιν ανηρ | derings, from πλανη, ης, ή. ην. 15. Γερων γεροντι γλωσσαν ήδιστης έχει, παις παιδι, και 14. αληθως, truly; ως αληθως, very truly. γυναικι προσφορών γυνη. 16. Παντες οι των αριστων Περσων 15. ήδιστης, 8eetest, the superlative degree of ήδυς, Sweet ; παιδες επι ταις βασιλεως θυραις παιδευονται. 17. Ξιφος προσφορον, pleasant, from προσφορος, ον, conducive to (προς and τιτρωσκει σωμα, τον δε νουν λογος. 18. Η φρονησις μεγιστον
φερω). εστιν αγαθον. 19. Πολεως ψυχη οι νομοι. 20. Η τυραννις | tive of αγαθος.
16. αριστων, the best, that is, noble, from αριστος, 8 εuperlaαδικιας μητηρ εστιν. 21. Ο δειλος της πατριδος προδοτης 17. Ξιφος, ους, τo, a sword; τιτρώσκει, wounds, from τιτρώσκω,
22. Οι αγαθοι ανδρες θεων εικονες εισιν. 23. Οι I wound. Νομαδες των Λιβυων ου ταις ημέραις, αλλα ταις νυξιν αριθ- 18. μεγιστον, the greatest, superlative from μεγας, great. μούσιν. 24. Χαλεπον εστι λεγειν πρ ος γαστερα, στα ουκ 20. τυραννις, ίδος, ή, usurped power, tyranny και αδικιας, ο έχoυσαν. 25. Ηφαιστος τω πoδε χωλος ην. 26. 'H Mndela injustice (a privative, and dun, right, justice). γραφεται το παιδε δεινον υποβλεπουσα. 27. Ηθους βασανος
21. δειλος, η, ον, cowardly, ο δειλος, the coward; προδοτης, εστιν ανθρωποις χρονος. 28. Οι οφεις τον ιον εν τοις οδουσιν
ov, ó, a betrayer, traitor.
22. εικονες, ιmages ; εικων, ονος, o, an image. εχουσιν. 29. “Ο Παρνασσος μεγα και συσκιον ορος εστιν.
23. Nομαδες, εhe nomads, or wandering tribes, from νομας, Εν βοιωτια δυο εστιν επισημα ορη, το μεν Ελικων καλουμενον, αδος, and that from νεμω already explained; αριθμoυσιν, they ετερον δε Κιθαιρων. 31. Ο Νειλος εχει παντοια γενη ιχθυων. number, from 'αριθμεω, I number, our arithmetic. 32. Tιμα τους γονείς. 33. Αναχαρσις την αμπελον ειπε τρεις 24, έχουσαν, λανng, present participle from εχω, I have; it φερειν βοτρυς τον πρωτον, ηδονης' τον δευτερον, μεθης: τον | agrees with γαστερα,
25. Ηφαιστος, Vulcan ; χωλος, η, ον, lame. τριτον, αηδιας. 34. Πονος ευκλειας πατηρ (sc. εστιν). 35.
26. Μήδεια, ας, ή, Medεα; υποβλεπουσα, 8cooling , from υτο, Ωκεανου και Τηθυος παις ην Ιναχος. 36. Οι τεττιγες σιτουνται under, and βλεπω, 1 took. την δροσον. 37. Κλεανθης εφη τους απαιδευτους μονη τη 27. ηθους, of character, from το ήθος και βασανος, ου, ή, a touchμορφη των θηριων διαφερειν. 38. Αναχαρσις ονειδιζομενος οτι stone, test. Σκυθης ην, ειπε, τω γενει αλλ' ου το τροπο. 39. Κολαζονται
28. Όφις, οφεως, o, a serpent ; ιος, ου, α άart, sting. εν αδου παντες οι κακοι, βασιλεις, δουλοι, σατραπαι, πενητες,
29. Παρνασσος, Parnassus, 8 mountain of Phocis, on whis πλουσιοι, πτωχοι. 40. Αί Φορκου θυγατερες γραιαι ησαν εκ | and σκια, α ελαάε.
was Delphi ; QUOKLOS, ov, overhang with clouds, from ovv, with γενετης. 41. Ζηνων εφη, δειν τας πολεις κοσμειν ουκ αναθη
30. επισημος, ον, distinguished, remarkable, from επι, μασιν, αλλα ταις των οικουντων αρεταις.
(here an intensive), and onua, a sign, whence our semaphore, In giving the vocabulary of these recapitulatory exercises, that is, a telegraph ; 'Elixwv, Helicon ; Kelapwr, Cithaeron; I shall take each sentence in the order in which it stands, kalovjevov, called, named, participle agreeing with to, that is, because the learner will here need more aid than he has opos ; &repos, a, ov, other, the other. hitherto received.
33. Ανάχαρσις, Anacharsis ; ειπε, εαid; ηδονης depends on VOCABULARY TO THE EXERCISES FROM THE CLASSICS. βοτρυς και μεθη, ης, ή, intoxication; αηδια (from α, not, and ηδυς, 1. Μια, ome, from the numeral είς, μια, έν, one; χελιδων, sueet), diogust.
34. ευκλεια, ας, ή, glory, distinction. nom. sing., ferm., agreeing with μια και χελιδων, χελιδονος, α
35. Ωκεάνος, ου, ο, Ocednus, Ocean considered as a divinity; swallow. 2. See note.*
Τηθυς, ος, η, Tethys, a sea-goddess.
36. σιτεομαι, I feed on; δροσος, ου, ή, dou. This sentence contains nothing that the student ought not to
37. Κλεανθης, Cleanthes ; εφη, said; απαιδευτος, ον, untaught, know. I therefore leave him to the knowledge he has, or may uneducated; popon, ns, , form; diapepw, I differ. have, already attained, and so in future shall I do without giving 38. Oveidi'w, I reproach, Anacharsis being reproached ; Exv0ns, notice thereof,
a Scythian. 1
39. Kolašw, I punish; ev qdov, oopy is understood, in the force also exhibits very variable effects, according to the elevaabode of Hades, in hell; oatpanns, ou, ó, a satrap or governor tion of the temperature of bodies. In certain cases, by separaof a province; nevns, ntos, poor ; atwxos, , ov, begging ; ting, the particles and diminishing cohesion, heat produces oi atwxoi, beggars.
combinations. For example, between sulphur and oxygen 40. Ypala, y, old, an old woman, grey-haired.
the affinity is without effect at the ordinary temperature, 41. deiv, that it was necessary, proper ; avadnja, tos, To, an while at a high temperature these bodies combine and produce offering, public monument, from ava, up, and riêmur, I place; a fixed compound called sulphurous acid. In other cases, on TWV OLKOVVTWY of their inhabitants, from oikew, I inhabit, com- the contrary, heat destroys combinations, by communicating pare oικoς and οικια.
to their elements unequal expansibility. Hence
many metallic oxides are decomposed by the action of heat. (To be continued).
Adhesion is the molecular attraction exhibited in bodies which stick together by contact. Two plates of glass, for
example, when placed in contact with a weight upon them, ON PHYSICS OR NATURAL PHILOSOPHY. adhere so strongly that they cannot be separated without
breaking, after the weight is removed. The force of adhesion No. VII.
acts between solids and liquids, and between solids and gases.
Adhesion between solids is not merely the effect of atmoMOLECULAR FORCES.
spheric pressure, for its action is exhibited in a vacuum. This Nature of Molecular Forces—The phenomena which bodies force increases in proportion to the degree of the smoothness constantly exhibit lead to the conclusion that their particles of the surfaces in contact, and to the length of the duration are always under the action of two opposite forces, one of of contact; for the resistance to their separation is greater in which tends to make them attract, and the other to repel, one proportion to the time that their contact has continued. Moreanother. The first, which is called molecular attraction, varies over, adhesion between solid bodies independent of their in the same body only with the distance of the particles ; the thickness-a fact which indicates that the molecular attraction second, which is produced by heat, varies with the inten- acts at indefinitely small distances. sity of the agent and with the distance of the particles. From When solid bodies are immersed in water, alcohol, and most the mutual relation of these forces, and from the disposition other liquids, they are found covered with a coat of the liquid and arrangement which they give to the particles, arise the when taken out of it; and this is simply the effect of adhesion. different states of bodies, namely, solid, liquid, and gaseous. Adhesică is produced between solids and gases, similar to
Molecular attraction only acts at distances incalculably that vetween solids and liquids. Thus, if we immerse a plate small. Its effect is nothing at any sensible distance, a property of glass or of metal in water, we perceive air-bubbles floating which distinguishes it from gravity and universal gravitation, on the surface. Now, in this case the water does not penewhich act at all distances. We are ignorant of the precise trate the pores of the plate, but the air-bubbles arise only laws according to which molecular attraction operates. from the expulsion of the air which surrounded the plate like According to the manner in which it is viewed, it receives the the coating of a liquid. A series of phenomena proceeding different names of cohesion, affinity, and adhesion.
from molecular attraction, under the names capillary attracCohesion is the force which unites similar particles of matter tion, endosmose, absorption, and imbibition, shall be brought under to each other, that is, matter of the same kind, as for instance our notice in the sequel. two particles of water, or two particles of iron. This force is almost nothing in gases, sensible in liquids, and very great in
PARTICULAR PROPERTIES OF SOLIDS. solids. Its intensity is diminished when the temperature of a Having explained to the student the principal properties of body is raised, while the repulsive force arising from heat is matter common to solids, liquids, and gases, we shall in this increased. Hence, when solid bodies are heated, they ulti- lesson treat of some particular properties of solids; such as mately become liquid, and even pass from this state into the the elasticity of traction, the elasticity of torsion, the elasticity of aeriform or gaseous state.
flexure, tenacity, ductility, and hardness. Cohesion varies not only with the nature of the bodies, but also with the arrangement of their particles. To the modifica- the nature of elasticity in general, and referred chiefly to that
Elasticity of Traction. In our second lesson we explained tions which cohesion undergoes in different circumstances are developed by pressure. In solids, however, elasticity is deveto be attributed the different qualities of tenacity, ductility, loped also by traction or extension, by twisting or torsion, and and hardness.
by flexure or bending. In liquids, taken in large quantity, gravity overcomes cohesion. Hence liquids, constantly yielding to the action of
In ascertaining the laws of the elasticity of traction, M. gravity, and assuming no particular form of their own, take Savart employed an apparatus represented in fig. 18. This always that of the vessels in which they are contained. In small
Fig. 18, drops of liquids, however, cohesion overcomes gravity, and they assume the spherical or spheroidal form. This may be seen in the drops of dew suspended on the leaves of plants ; and the same phenomenon is observed when a liquid is poured on a plane horizontal surface and does not wet it, as mercury upon wood. The same experiment can be made with water, if the surface be previously rubbed or sprinkled with a light powder, such as lamp-black, &c.
Affinity is the attraction which takes place between heterogeneous substances; in water, for instance, which is composed of two atoms of hydrogen to one of oxygen, it is affinity which unites these two bodies ; but it is cohesion which unites two particles of water. Hence, it is evident that in compound bodies cohesion and affinity act together, while in simple bodies it is only cohesion that unites the particles. Affinity is the form of attraction to which we refer all the combinations and decompositions of chemistry.
Every cause which tends to weaken cohesion increases affinity. The latter is, in fact, increased by the state of division in a body; it is also increased by the liquid or the gaseous state of a body. This force is particularly developed by a body when it is disengaged from combination with another body and isolated or left free to yield itself to the action of other bodies for which it may have an affinity. This
apparatas consists of a wooden stand, from the top of which the angle of torsion is inversely proportional to the fourth are suspended the rods or wires on which the experiments are powers of the diameters. made. At their lower extremity is fixed a scale-pan for hold- Elasticity of Flexure.-All solids cut into thin lamina or ing the weights used in determining the force of traction, and plates, and fixed at one of their extremities, when more or less two points A, B, are marked, between which the exact distance bent from their natural position, return to that position as soon is measured, by means of a cathetometer, before the scale-pan as the force which bent them is removed. This property is very is loaded.
evident in tempered steel, caoutchouc, wood, and paper. CerA cathetometer or vertical measurer, as the derivation from the be extended to a very great length, or be made extremely
tain bodies can be bent only at a very small angle, unless they Greek implies, is a brass scale divided into inches and fractions thin. For example, glass cannot be bent unless it be formed of an inch, placed upon a stand which is brought exactly into of very thin laminæ about a foot in length, or be reduced to a the vertical position by adjusting screws at the bottom. On this very fine thread. In the latter state it becomes so flexible, scale there is placed å sliding telescope sight, exactly at right that it can be formed into waving plumes, or woven into angles to the vertical, which carries a vernier capable of cloth. measuring to fractions of an inch, each one hundredth part of the former. By fixing this telescope sight successively at the
Numerous applications of the elasticity of torsion are to be points A and B, as seen in the figure, we obtain by means of seen in the construction of bows, cross-bows, watch-springs, the graduated scale the exact distance between these two carriage-springs, spring-balances, and dynamometers, or instru. points. Now by loading the scale-pan with weights, and ments for measuring the intensity of forces, chiefly of animal again measuring the distance between the points A and B, we power. The elasticity of hair, wool, and feathers is employed ascertain the amount of elongation or extension arising from in the construction of mattresses, cushions, and other pieces of the traction of the weights.
domestic furniture, By experiments conducted in this manner, it has been found Whatever may be the species of elasticity under considera80 long as the limit of elasticity has not been exceeded, that tion, as we have formerly remarked, there is always a limit to the traction or extension of rods and wires is regulated by the its action; that is, a degree of molecular displacement beyond three following laws :
which the elastic bodies are fractured, or rendered incapable Ist. Metal rods and wires have their elasticity of extension of reassuming their original form. Owing to several causes, perfect; that is, they resume exactly their original length as this limit is variable. For instance, the elasticity of several soon as the force of traction ceases,
metals is increased by hardening them; that is, by bringing 2nd. In the same substance, and having the same diameter, their particles more closely together, as in wire-drawing, the extension or elongation is proportional to the force of plate-rolling, or hammering. Some substances, as steel, traction and to the length.
cast iron, glass, &c., become more elastic and at the same time 3rd. In rods or wires of the same length and of the same harder by the process of tempering, which consists in cooling material, but of unequal diameter, the extensions or elonga- a metal suddenly after it has been raised to a high temperations are in the inverse ratio of the squares of the diameters. ture.
Both calculation and experiment prove, that when bodies Elasticity, on the contrary, is diminished by the process of are extended by traction, their volume or bulk is increased. annealing, which consists in bringing bodies to a lower tempera
Elasticity of Torsion.—The laws of the torsion of metal wires ture than that required for tempering, and then slowly cooling and threads of various substances were first ascertained by them. It is by this process that the elasticity of springs is M. Coulomb, a French philosopher, who died in 1806. In his graduated at pleasure. researches on this subject he employed an apparatus called the In the operation of tempering, steel and cast iron acquire a balance of torsion ; this is composed of a fine metallic wire or great degree of hardness, and it is chiefly for this purpose that thread, fastened to a stand at its upper extremity, and tempering is employed. All cutting instruments are made of stretched vertically by a weight, to the centre of which is tempered steel. But there are some bodies upon which temattached a horizontal pointer or index, Below this is placed pering produces an entirely opposite effect. Thus the combi& graduated circle or dial-plate, attached to the stand by a nation of metals called tam-tam, which is composed of one part bliding piece and tangent-screw; the centre of this circle, which of tin to four parts of copper, becomes ductise and malleable is exactly under the centre of the index, is so adjusted as to when it is suddenly cooled ; on the contrary it becomes hard be exactly under the direction of the wire or thread produced and brittle like glass when slowly cooled. Sulphur exhibits when it is in the vertical position. Now, if the index be the same phenomenon; when cooled slowly, it is hard and turned round, out of its position of equilibrium, by the amount brittle; but when cooled suddenly, it becomes soft and ductile of a certain angle, which is called the angle of torsion, the force like wax; but it does not continue in this state. necessary to put the index in this new position is called the
Glass presents a curious phenomenon of tempering in what force of torsion. When this turning round of the indes takes are called Dutch tears or Prince Rupert's drops, names given to place, the particles of the wire or thread which were before small globules of glass, in the shape of tears, which in a state situated in the straight line parallel to its length or axis, are of fusion are dropped into cold water. Glass being a bad now situated in a spiral round it. If the limit of elasticity conductor of heat, the central parts of these globules are still has not been exceeded, the particles have a tendency to return in a state of fusion when the parts in contact with the water to their original position, and this tendency is verified by their have become solid. From this, it follows
that their molecular actual return to it, as soon as the force of torsion is removed; forces being unable to resume the state of stable equilibrium, but they do not remain in this position. For, in consequence the globules become so brittle that fracture at a single point of of their acquired velocity, they pass this position, and produce their surface is sufficient to make them burst in pieces with a torsion in a contrary direction; thus the equilibrium is again loud noise, and at once fall into powder. As glass undergoes disturbed, and the wire revolving now on itself, the index does the real process of tempering when too suddenly cooled, the not point to zero on the dial-plate until after a certain num-brittleness of newly-made articles is diminished by annealing ber of oscillations on both sides of this point.
them over a fire, from which they are very slowly withdrawn. By means of this apparatus Coulomb proved that when the
Tenacity is the resistance which bodies oppose to their amplitudes of the oscillations do not exceed a certain number extension by traction. In order to determine the amount of of degrees, these oscillations are regulated by the following this force in different bodies, they are formed into cylindric laws :
or prismatic rods, and subjected, in the direction of their 1st. They are very sensibly isochronous, that is, performed length, to the traction of a weight of so many pounds as are in equal times.
sufficient to determine the force of rupture or separation of 2nd. In the same wire the angle of torsion is proportional their particles, to the force of torsion.
Tenacity is directly proportional to the force which produces 3rd. In wires of the same diameter, and with the same force transverse section of the rods or prisms employed in resisting
the rupture, and inversely proportional to the area of the of torsion, the angle of torsion is proportional to their length. the strain. According to numerous experiments upon metals,
4th. In wires of the same length, and with the same force, the force necessary to produce rupture is nearly triple of that
which corresponds to the limit of elasticity. Tenacity
Woods. diminishes with the duration of traction. It is found that, Box................
tons, after a certain period, metallic and other rods give way under Ash..
8 smaller loads than those which would produce immediate Teak
7 rupture ; and in all cases, the resistance of bodies to traction
Beech ................... is less than their resistance to pressure.
Oak... Tenacity varies not only in different bodies, but also in those which are composed of the same matter, and in equal quantity
Pear according to their difference in form. In rods of equal sec
Mahogany tional area, the prismatic form possesses less power of resistance
Elm than the cylindric. In a given quantity of matter, the hollow
6 cylinder possesses a greater power of resistance than the solid
6 cylinder, and the maximum of tenacity in the former takes Ductility. This is a property which many bodies possess, and place when the outer diameter is to the inner one in the ratio it consists in their power to change their form under various of 11 to 5.
degrees of pressure or traction. In some bodies, as clay and In the same body, the form has the same influence on the wax, a very slight force is sufficient to produce a change in their resistance to pressure that it has on the resistance to traction. but in metals, strong force is required, as in hammering, wire
form; in others, as glass and rosin, it is necessary to add heat; Hence, a hollow cylinder, of equal matter and altitude, has a greater power of resistance to pressure than a solid one; denominated malleability when it is produced by the operation
drawing, and laminating or reducing to plates. Ductility is whence it follows that the bones of animals, the feathers of of the hammer. The most malleable metal is lead; the most birds, the stalks of grass and of a great number of plants, being ductile in laminating is gold; and in wire-drawing, is platihollow, present a greater resistance to rupture by pressure num. The great ductility of platinum enabled Wallaston to or traction than if they were solid, the mass of matter being produce wires of this metal not exceeding the thirty-thou. the same,
sandth part of an inch in diameter. This was effected by coverTenacity, as well as elasticity, varies in the same body ing a platinum wire of about one-hundredth of an inch in According to the direction in which force is applied. In wood, diameter with a coating of silver until the diameter of the for example, the tenacity and elasticity are greater in the compound wire was about of an inch in thickness ; then by direction of the fibres than in any crossing direction. This drawing this wire until its diameter was as fine as possible, the difference is, in general, manifested in all bodies whose contex- two metals were equally extended by the process ; and lastly, ture is not the same in all directions. Yet M. Savart dis- by dipping the wire in nitric acid, the silver was dissolved covered, by means of ingenious experiments on the sonorous and the platinum wire remained, exhibiting the extraordi. vibrations of bodies, that a difference in this respect existed in nary degree of fineness above mentioned. A thousand yards of a number of bodies whose contexture was completely homo- this wire would weigh only about three-quarters of a grain ; geneous ; such as zinc, lead, brass, glass, resinous bodies, &c. and a quantity equal in bulk to a common die would reach He also discovered this difference in certain directions perpen- from London to Vienna. dicular to each other, which he called axes of stronger and Hardness. This property of matter is the resistance which weaker elasticity. M. Savarç attributed this modification of bodies present to "scratching or abrasion by other bodies. these properties to a symmetrical arrangement which the This property is only relative, that is, a substance may be particles of bodies tend always to assume when they are slowly hard with reference to one body and soft with regard to cooled. It is of the greatest importance, in the arts of con- another. The relative hardness then consists in this, that one struction, to take into consideration the limits of the tenacity body can be made to scratch or abrade another without being
and compressibility of materials. In suspension-bridges, for itself capable of being scratched or abraded by the other. The instance, the stability of the structure chiefly depends on the hardest of all bodies is the diamond, for it will scratch all tenacity of the rods which support the road-way. The follow- bodies, but cannot be scratched by any. After the diamond ing table exhibits the weights in tons on the square inch in hardness follow the sapphire, the ruby, the rock-crystal, which certain bodies can support in vertical traction before the flint, the stone, &c. Metals in a state of purity are generupture, or in other words, the limit of direct cohesion or rally soft. Lead can be scratched with the nail
. The processes tenacity.
which increase their elasticity also increase their hardness; such
as tempering, annealing, &c. 'Alloys or mixtures are harder Metals.
Weights. than metals. Thus in jewellery and in coining, the hardness Wrought iron wire, from do to go from 60 to 91 tona.
of gold and silver is increased by alloying them with copper. inch diameter
The hardness of bodies does not increase in proportion to Ditto, ito inch diameter
their resistance to pressure. Glass and the diamond are much Wrought iron bars
harder than wood, but they present less resistance to the blow Ditto, hammered
of a hammer. The hardness of bodies is usefully employed in Wrought iron, rolled
from 14 to 18 polishing-powders, such as emery, pumice-stone, and tripoli. Wrought iron chains
The diamond, which is the hardest of all budies, can only be Cast iron
ground or polished by means of a powder which is merely Cast steel
pulverized diamond, Litto, tilted
Case-HARDENING is a process by which the surface of artiSibel blistered and hammered
cles made of wrought iron is converted into steel. The articles Shar steel.....
to be case-hardened having been prepared in wrought iron, Ran steel
they are placed in an iron box in layers, in order to receive Damascus steel..
from 31 to 44 that degree of hardening on the surface which will prepare Coppei cast
them for receiving a final polish. A layer of animal carbon Copper hammered
(horns, hoofs, skins, or leather), at first so burned as to be Sheet cooper
capable of reduction to powder, is spread over each; the box, Copper wire
then carefully covered and luted with an equal mixture of Platinum vire
clay and sand, is kept at a slight heat for half an hour, and its Silver wire
contents are then emptied into water. By this means, a surface Cast silver,
of hardened steel is obtained over the whole of the article, of Gold wire
a thickness depending on the duration of the time in which Cast Gold
heat has been applied. This process is particularly applicable Brass
to articles wanting external hardness and polish, as fire-irons ; Gun metal.
but it is not applicable to cutting instruments. Tin wire..... Sheet lead, milled.
• In the direction of their übres.
LESSONS IN ITALIAN GRAMMAR.--No. VII.
4. Cia, Cie, Ohii, Cio, Ciu, Gia, Gie, Gii, Gio, Giu, BY CHARLES TAUSENAU, M.D.,
English. of the University of Pavia, and Professor of the Itaļian and German
Blue bottle (plant) Languages at the Kensington Proprietary Grammar School
The look, face
A mean fellow
Cup or glass
Ice, frost, cold
jô-vai ILLUSTRATING SBYBRAL COMBINATIONS OF THE LETTERS @, g, Giuda
Jove, Jupiter jbo-dah
Baciare bah-tchah-rai To kiss, salute
Acciuga aht-tch6o-gahg Anchovy
Belly, paunch, body
He will row
I catch or snap
Biggin, a child's cap
A Roman coin, July Leghe lái-gai
5. Gua, Gue, Gui, Guo, Qua, Que, Qui, Quo.
A Guelph, an ancient
coin of Florence Chiesa keeki-zah Church
I follow or pursue
Almost, as if
The vowel i before e, when both follow the consonant c, are
pronounced as though the i was not there, and the whole combinaSuochio sook-keeo Auger, juice
tion only ce. The same remark, however, made with regard to Schiuma skeebo-mah
the combinations cia, cio, and cit~that in a more measured
enunciation the vowel i in these cases is slightly touched3. Gia, Guie, Gio.
holds good here also. Italian.
| The observation just made in the foregoing note with respect to Pronounced. English.
cie" is strictly applicable to the syllable gie. It is always pronounced Ghiaja gheekh-yah
as though the i was not there ; unless slightly touched in measured Ghiera gheee-rah
pronunciation. Ghiova gheeô-vah
§ No observation has yet been made in reference to the proRinghiare rin-gheekh-rai
nunciation of the double c (00). This depends, as well as the Preghiera prai-gheeê-rah Prayer, desire pronunciation of double o (99), on the vowel that follows the Singhiozzo sin-gheeó-tso1 Sob, sigh, hiccough
latter e. If that vowel is a, o, or u, the oc is sounded like a double Cinghia tchín-gheeah
k (kk) or ck. For example, bocca (bók-kah), mouth; becco (bêk-ko),
beak; accusare (ahk-koo-záh-rai), to accuse, If, however, that Unghie Oon-gheeai
e ise or i, the double c (cc) is sounded Ringhio rin-gheco
Igrin, grinding the teeth something like tch in the English word match, only perhaps
stronger, and with vibration. On that account, I have tried to
imitate the stronger sound of the c by the letters ttch, placing the * I have explained the combination chi to be sounded like kee. first t in the first syllable, and tch at the beginning of the second, When one of the five vowels follows this syllable, it is so just as I have attempted to imitate the sound of the gg by placing intimately blended with the following vowel, that a kind of d in one syllable, and ) at the beginning of the next, in such words squeezed sound of our is the result, the voice sliding, as it were, as paggi (páhd-jee), pages, attendants. The remark with respect from chi to the next vowel with great rapidity.
to the pronunciation of the gg, however, holds good of oc; the + The remark made with respect to the syllable chi, fol. first o occurs, and glide as quickly as possible to the pronunciation
voice must not pause too long on the t of the syllable where the lowed by any of the five vowels, is equally applicable to the of the second c, which must be very much vibrated. In this way syllable
ghi followed by a vowel : here, likewise, the syllable ghi is, a more equal distribution of the sound tch between the two sylla as it were, squeezed, and the voice must slide into the pronuncia-bles will be effected, which will produce the correct sound o. tion of the vowels that follow ghi with great rapidity.
the c; and my imitation of that sound by ttch has no other object * The double xx, as well as the single e, may have the mild than to indicate to the reader the necessity of giving a stronger gound of the word adze (with which, by-the-bye, the ds in the word vibration to the cc. It is obvious that when oc is followed by con Windsor corresponds), or the hard sound of ts in Switzerland. sonants, it must be pronounced like k, just as the singie e in the According to modern orthography, the letter z is generally doubled like case must be so pronounced. For example, acclamare (abk in the middle of words between two vowels, and the pronunciation klah-máh-rai), to elect by acclamation, to applaud; accrescere (ahk of this zz scarcely differs from that of the single z: However, krái-shai-rai), to increase, &c. When between the oc and the before diphthongs, -as, for example, ia, ie, and i0,-& must remain vowels e ori the letter his interposed, the cc is also sounded like k, aingle, and has always, in such a case, the sharp sound. For as well as the single c in such cases and for the same reasons, the example, ringraziare (rin-grab-tseekh-rai), to thank; pigrizia (peek being a mere auxiliary letter to indicate that oo before . and i is grée-éseeah), idleness; inexie (ee-ne-tseéai), follies ; Bonifacio (Bo- not to have the sound of ttch, but of kk, as in chiochera (ksk-kai-rab) nee-fáh-tseeol, Boniface.
tea-cup ; chiacchiera (keeshk-keeai-rah), chit-chat,