« ForrigeFortsett »
| itself. This peculiar manner of espressing a passive act or ENGLISH-SPANISH.
emotion must be carefully noted. Mary is loved by (de) James. The Spanish-woman is loved by
VOCABULARY. the Frenchman. We-were (perf.def.) surpassed in generosity. The earth was (perf. def.) created by (por) God. She was (perf. Llamar, to call, to name. def.) calumniated openly. They-were surpassed in generosity. Doblar, to double, to increase.
Llenar, to fill. All things were creared by God. This letter was written Usar, to use.
Continuar, to continue. (escrita) for Mary. Those books were written by the lawyer. Creer, to believe, to think.
Engañar, to deceive.
J'ender, to sell. I have been abused. The city was (perf. def.) burnt. The
Abrir, to open.
Botella, bottle. house was burnt. Yesterday the French ambassadorwas!
Clamor, noise, clamour.
Escuela, school. presented? to-the queen of England. Yesterday the sisters
Puerta, door. and daughters of the Spanisha ambassador were presented
Sítio, siege. to-the queen, The French-women were calumniated openly. These gentlemen have been abused. The cities have been burned. The city will-be burnt. We shall not be surpassed
MODEL SENTENCES. in generosity. Yesterday the son of the Eoglish? ambassador was presented to the queen. Yesterday I was presented to Aqui se habla? Español", here | Pedid, y se? 053 dara', ask-ye,
Spanish is spoken.
and it shall be given to.
La isla se llamaba Melita, the you. Remark.—The inflections of passive verbs should now be
island was called Melita. Se5 hang segadot losl prados, written in all the moods and tenses of the three regular con- El rio se ha helado, the river is the meadows have been jugations.
(has been) frozen.
moved. Instead of employing the auxiliary verb ser, to be, and the In many of the following sentences the nominative will be participle of the verb agreeing with its nominative, the per- found placed after the verb, this being a very common order sonal reflective pronoun se is often used in the third person of construction in Spanish, especially in sentences in which sé, singular and plural with the proper tense of the active verb. with the active verb, is used in place of the passive verb. Thus, we may say el libro ha sido hallado, or el libro se ha hallado, * and both forms are to be rendered in English, “the book has
SPANISH-ENGLISH. been found." This is a very important rule of Spanish grammar, and must be kept in mind by the student. The follow- Esta muger se llama María. Aqui se hábla el Ingles. Se ing will serve as examples of this method of placing se before cree. Llamad, y se os abrirá. Este vino se vende á tres pesos the verb, which in such a case corresponds to the same tense la botella. Se dobla el clamor, Se enagaña V. Se usan conjugated passively.
plumas de oro? ¿Qué libros se usan en esa escuela? La El libro se ha hallado, the book | Las aguas se tornaron amargas; água. La casa se llenará de humo. Se llenó toda la cuidad
botella se llenará de (with) vino. Las botellas se llenarán de has been found.
the waters turned
de humo. Se abrirán las puertas. Aquí se habla el Frances. El libro se abre, the book is bitter. opened, or opens.
La casa se quemó, the house Se cumple la profeeía. Se abrirá la puerte. La cuidad se EL se llamaba Caifás, he was
quemó. Las casas se quemaron. Se abrió el libro. Aqui se
was burnt. called Caiaphas. Aqui se habla Español, Spanish cumplen las profecías. Se continuara la carta. venden libros. Este vino se vende á dos pesos la botella. Se
Este hombre La voz se repitió, the voice was is spoken here.
se llama Pedro. Se abrieron todas las puertas. Se continurepeated. Se dice, it is said.
arán esas cartas. Se doblará el clamor. Se engañan los Su glória se verd, his glory shall | Se publicó, it was published.
jueces. Esa profecía se ha cumplido. Se ha engañado ymd. be seen.
Se habla de un sitio. Se ha levantado el sitio. Se usan The above examples rendered literally mean--the book has sombreros de seda? Las casas se llenaron de humo. ound itself; the book opens itself; he called himself Caiaphas; the voice repeated itself; his glory shall see itself ; the
ENGLISH-SPANISH. waters turned themselves bitter; here speaks itself Spanish; the house burnt itself; it says itself; it published itself. We This woman is called Mory. Here French is spoken. It may say in English, the voice prolongs itself, or, the voice is is-believed. Knock (llamad), and it shall be opened to-you. prolonged; the man deceives himself, or, the man is deceived; This wine is sold at (á) three shillings a (la) bottle. The clamour so that the only difference between the Spanish and English is doubled. You' (V.) are deceived. Are gold pens used ? syntax in this matter is, that the rule is applied far more ex- What books are used in that school: The bottles will be filled tensively in Spanish than in English. Thus we may say, in with (de) wine. The bottles will be filled with (de) water, both languages, the voice repeats itself, la voz se repite, mean- The house will be filled with smoke. All the city will be filled ing, the voice is repeated; but we cannot say in English, the with smoke, The docrs will be opened. Here English is gound hears itself," for " the sound is heard.” In Spanish, spoken. The prophecy is fulfilled. I'he door will be opened. however, we can say, la voz se oyó, or, la voz fué oida, the voice The city is burned (perf. def.). The houses are burned. The was heard.
book is opened (perf. def.). Here books are sold (pres). This
wine is sold at two shillings a bottle. The prophecies are fulRemark.--The exercises in this portion of the lesson are filled (pres.) The letter will be continued. This man is designed to show the manner in which the reflective personal called Peter. All the gates were opened (perf. def.). Those pronoun se is employed in Spanish to express passive action. letters will be continued. The clamour will be doubled. The Thus it can be said in Spanish, en la Gaceta de York de ayer se judges are deceived. The prophecy has been fulfilled. You leen las siguentes líneas, in the York Gazette of yesterday read (omd.) have been deceived. It is spoken of a siege.* The themselves the following lines, meaning, in yesterday's York siege has been raised. Are silk hats used? The houses were Gazette the following lines are (or may be) read, ¿ Como se filled (perf. def.) with smoke. Those prophecies have been entenderá lo que se dice? how shall-understand itself that which fulfilled. says itself ? meaning, how shall be understood that which is
The passive verb is sometimes formed by the auxiliary verb said: Las ventanas se han cerrado, the windows have shut estar, instead of ser; as, el caballo está lastimado, the horse is themselves, meaning, the windows have been shut. It is be injured; la casa está mal construida, the house is badły conlieved, it is said, the book is opened, can be rendered instructed. Spanish by the reflective pronoun, thus, se cree, se dice, se abre Verbs are conjugated interrogatively, by placing the pronoun el libro; literally, it-believes itself, it says itself, the book opens
• Literally, "the book has found itself."
• In English It would be better to say, a siege is spoken of. In Spanish | it can be said, hablan de un sitio, they (i. e. people) speak of a siege.
after the verb; and negatively, by placing the adverb so before | The judge pardoned the man who robbed Peter's fathér. the verb; as,
They robbed the woman whom we rewarded. My male. à Amo yo ? love I? or, do I El no come, he does not eat.
servant slew his father. Honour ye your parents (padres). love ?
Ellos no escribirian, they would l.pardoned all my debtors. 1-love thee like (como) a father: i Come él ? does he eat?
Peter loves me like a brother. The ladies will-reward their
not write. Escribirian ellos ? would they : No apprenderás tú? wilt thou will visit some of my friends to-night (esta noche). I wil
female-servants. We-will-visit the queen this night. We write?
not learn Yo no amo, I do not love.
reward him who honours me. The father loves his 8988.
John killed his friend. If an objective pronoun cone before the verb, the negative no is then placed immediately before such pronoun; as, i No lo habeis oido ? have ye Yo no le vi, I saw him
ANSWERS TO CORRESPONDENTS. not heard it?
JOHN MIDGLEY : Our space is now too nearly exhausted for the intrs. It is not the general practice to use the nominative personal duction of the subject you inention. pronouns in asking questions; thus, i amo? come ? mean the SCIENTIB AMATOR: Book-keeping by double entry is not suitable for same as įamo yo ? ; come tid? Nor is it absolutely necessary to show the whole amount received in the course of the day, witbout specie
retail trade. Ready money may be entered at the close of each day, so w to place the nominative pronoun or noun after the verb, as the fing each particular sum. Any of the inany works on book-keeping wid interrogation mark shows the sentence to be interrogatory; give all
Messrs. Chambers have publishe) oge, and thus, i yo amo ? į amo yo ? or ; amo? each means, do I love
Mr. Souter, in Fleet-street, another, The latter may be bad for a shilung,
HENRY COLSON : Again and again have we expressed our reyret at the One of the most important rules in Spanish syntax is that respondents should, after so many notices, persist in requesting us to do
impossibility of giving lessons in Hebrew. We cannot understand why carby which a noun in the objective case, if it be a person, or what we have repeatedly stated is beyond our power. inanimate thing personified, and the direct object of a verb, is A. W.: Make inquiry of booksellers. to be preceded by the preposition d. Thus, John loves his
William LONG: The only guides to a knowledge of what faturé eraml. brother, would be in Spanish, Juan ama á su hermano,* and Nobody can tell beforehand what they will be like. For information as te
nation papers are likely to be, are those which have already been given. not Juan ama su hermano; Peter slew the barber, would be, the future subjects, apply to Mr. R. W. Rothman, Registrar of the University Pedro mató al barbero, and not Pedro mató el barbero; I love of London, those who love me, would be, amo a los que me aman, and not amo los que me aman. These sentences can be altered in construction, without any change of meaning. Of course the
LITERARY NOTICES. preposition is not to be translated in English, but must always be used in Spanish before nouns in the objective case, governed COMPLETION OF CASSELL'S LATIN DICTIONARY. by an active verb, if these nouns express a rational being or
Now ready, price 9s. 6d., handsomely bound in cloth, personified object.+
CASSELL'S LATIN DICTIONARY.
In Two Parts:-1. Latin and English. 9. English and Latin. R$ !...
BBARD, D.D., and C. BEARD, D.A.
Sanar, to heal, to cure.
Part I.-LATIN-ENGLISH, price 4s., in paper covers; 53. cloth.
Part II. -- ENGLISH-LATIN, price 4s., in paper covers; 54. cloth. Recompensar, to reward. Visitar, to visit.
Cassell's LATIN GRAMMAR. By Professors E. A. ANDREWS and Noche (fem.), night.
STODDARD. Revised and Corrected. Deudor, debtor.
Price 3s. 6d. in cloth boards. CASSELL'S BRILLING EDITION OF FIRST LESSONS IN LATIN. Bs Pro
fessors E. A. ANDREWs and S. STODDARD. Revised and Corrected. Pria MODEL SENTENCES.
18. paper covers, or is.6d. neat cloth.
CASSBLL’s Lessons in LATIN.-Price 2s.6dc paper covers, or 36. Rez our nation.
A KEY TO CASSELL'S LESSONS IN Latin, Containing Translations of Cain mató a su hermano Abel, | A nadie rió, he saw nobody. all the Exercises. Price Is. paper covers, or 18.6d, cloth. Cain slew bis brother | Le amo como á un hermano, I.
CASSELL'S CLASSICAL LIBRARY.--The First Volume of this work, price Abel.
love him like a brother,
18. 6d, cloth, consists of a LATIN Reader, adapted to "Cassell's first Lessons in Latin." - Volume 11..comprises LATIN EXERCISES, price 28. Bex
cloth.-Volume III. contains. Thk ACTS OF THE APOSTLES in the Original SPANISH-ENGLISH.
Greek, with copious Notes and a Lexicon, price 2s.6d, neat cloth. El padre á sus hijos. Honramos al juez. El médico sana a los enfermos. Este juez no teme á Dios. Perdonamos a
Now ready, price 98.6d. strongly wound. nuestros deudores. Yo perdono a mis deudores. Dios ama á los que son buenos. Llamaron a los pintores. Ella tema al CASSELL'S FRENCH AND ENGLISH DICTIONARY: Americano. El médico sanará á muchos enfermos. El juez Composed from the French Dictionaries of the French Academy, Bescherie perdonó al hombre que robo al padre de Pedro. Robaron á Landais, etc. ; from the English Dictionaries of Ogilvie, Johnson Week la muger a quien recompensamos. Mi criado mató a su padre. etc.; and from the Technological and Scientific Dictionaries of borb Lisa Honrad á vuestros padres (parents). Perdoné á todos mis guages. By Professor DE LOLMr and HENRY BRIDORMAN, Esq. deudores. Te amo como (like) á un padre. Pedro me ama The following are the distinctive features which render this work superise
to any of the same clage now extant. como á un hermano. Las señoras recompensarán á sus cria
It has been compiled with duwu das. Visitaremos al presidente esta noche (co-night). Visi most modern words and phrases including those of science, arti,
care from the very best authorities. It contains
correct renderings of all 15 taremos a algunos de mis amigos esta noche. Recompensaré ture, commerce, law, politics, etc., as well as familiar conversation when al que me honra. La madre ama á sus hijas. Juan mató a su are indispensable to a knowledge of language, but yet are rarely, if ever, arrigo.
the two languages-the constructions of verbs, the force of preposicions, 1
the changes of meaning caused by different combinations of wordsman ENGLISH-SPANISH.
more copiously and carefully illustrated than elsewhere within the same The mother loves her daughters. We-ho: our the judge. to prevent the possibility of mistake. To crown all, the Work is as temoderia The physician heals the sick. This judge fears no God. in price as it is comprehensive in aim, accurate in detail, and everything We-pardon our debtors. I forgive my debtors. God loves arrangement.--The French-English Division, price 4s. paper covers of one
neat cloth; the English-French Division, price 48.
, os die those who are good. They-called the painters.
She fears the strongly bound. American. The physician will-heal many sick (persons). A SERIES OF LESSONS in French, on an entirely Novel and simple Ples
Reprinted in a revised form from the Working
Man's Friend." Price bike
by post 78. Above 30,000 copies of this work have been sold. . Literally, John ; * Wher alle applies only to ralionai beings or personified objects ; thus T**
CASSELL'S LESSONS IN FRENCH. Parts I. and 11.-es Professor Pause we cannot say, amo a la rerdad, bat amo la rerdad, I love the truth. Two Parts bound in One Volume, price 43, 60.
Ama a nuestra nacion, he-loves | Pi diruma
, muger, I-saw a wo-cloth.
the needle immediately returns to the zero point, and remains UN PHYSICS, OR NATURAL PHILOSOPHY. there as long as the inducing current passes through the No. LXIX.
2. At the moment when-the communications being broken (Continued from page 650.)
off-the wire c d ceases to be traversed by a current, there is DYNAMICAL ELECTRICITY.
again produced in the wire a b an induced current, instan
taneous like the former, but direct, ie, in the same direction PHENOMENA OF INDUCTION.
as the inducing current.
Matteucci's Apparatus. — Fig. 460 represents an apparatus Induction by Currents.—We owe our knowledge of this sub- invented by M. Matteucci, and constructed by M. Ruhmkorff ject chiefly to the able researches of our illustrious countryman, of Paris, for the purpose of exhibiting the development of curProfessor Faraday, who undertook them in the hope of ob- rents produced by induction, whether by the discharge of a taining electricity from ordinary magnetism, and under the Leyden jar or the passage of a voltaic current. influence of the consideration, that whether we adopt the This apparatus consists of two glass plates about a foot in beautiful theory of M. Ampère or another, or make any mental diameter, fixed vertically in two brass frames, A and B. These restriction whatever, it seems very extraordinary that as every plates rest upon moveable supports, and are capable of being electrical current is accompanied by a corresponding intensity brought near each other, or removed away from each other, as of magnetic action at right angles to the current, good con- may be desired. On the front side of the plate a is wound a ductors of electricity, when placed within the sphere of this copper wire, about one-twelfth of an inch in diameter, in a action, should not have a current induced through them, or spiral form. The two ends of this wire pass through the plate, some sensible effect produced, equivalent in force to such a one at the centre and the other at the upper part, and tercurrent. That his labours resulted in success, is not only a minate in small holders, like those represented at m and n, fact of importance in the history of electrical science, but also on the plate B. In these holders are placed two copper wires cne which strikingly illustrates the utility of physical theories c and d, covered with silk, which are intended to receive the in suggesting and directing experimental inquiries.
inducing current. On the side of the plate B which faces the Professor Faraday has given the name of currents of induction, plate A, is wound, also in a spiral form, a copper wire, not or induced currents, to instantaneous currents which are de- quite so thick as the wire c. Its extremities terminate in the veloped in metallic conductors under the influence of powerful holders m and n, which receive two wires h and i, intended to magnets, or even that of the magnetic action of the earth. transmit the induced current. The two wires wound on the
The induction produced by currents is established by means surfaces of the plates A and B are not only covered with silk, of a bobbin with two wires. This is a cylinder of pasteboard but each coil is isolated from the next by a thick layer of cr wood, round which are wrapped, first a thick copper wire, gum-lac varnish, an indispensable condition for experimentand then a thinner one, both covered with silk, fig. 459. They ing with the electricity of electrical machines, which is always
more difficult to isolate than that of batteries. Fig. 459.
To show the production of the induced current by the discharge of a Leyden jar, bring one end c of the wire into connection with the external armature of the jar, and the other with the hook. Directly the spark appears, as the electricity which passes along the wire c acts by influence on the neutral fluid of the wire wound on the plate B, an instantaneous current arises in the wire. In fact, a person who holds in his hands two copper cylinders connected with the wires i and h, receives a shock, the intensity of which is greater in proportion as the plates are nearer. This experiment proves that the electricity of electrical machines is capable of giving rise to
currents of induction, as well as that of the voltaic pile. are wrapped round contiguously, so as to form concentric and M. Matteucci's apparatus also serves to demonstrate the parallel electro-dynamical helixes, the spires of which are close production of induced currents by the influence of voltaic together, but not in metallic contact. The two ends of the currents. For this purpose, pass the current of a battery wire, a and b, being connected with the extremities of the wire along the inducing wire c, and at the same time connect the of a galvanometer, a voltaic current is passed along the thick two wires i and h with a galvanometer. Then, at the moment wire c d, which is called the inductor. The following pheno- when the inducing current begins or ends, the same phenomena mena then take place :
are observed as with the bobbin (fig. 459) already described, 1. At the moment when the wire c d begins to be traversed and the needle of the multiplier is more deflected in proportion by a current from c towards d, for example, the deflection of as the two plates A and B are nearer each other. the needle of the galvanometer indicates an inverse current- Induction by Magnets.—We have seen that the influence of a i.e. a current in a contrary direction to the former—in the wire current magnetises a bar of steel ; reciprocally, a magnet is ab, and one which is produced for a very short time only, for capable of producing currents of induction in metallic circuits.
Mr. Faraday has demonstrated this by means of a bobbin with experiments, they have employed the machine of Mr. Page, a single wire from six hundred to nine hundred feet in length. an American philosopher. The two ends of the wire being connected with a galvanometer, This machine consists of a strong horse-shoe magnet, before a strongly-magnetised bar is suddenly put inside the bobbin, the poles of which a rectangular plate turns about an axis which is hollow, and the following phenomena are ob- parallel to the two branches of the magnet, and equally served:
distant from both. These branches are surrounded with two 1. At the moment when the bar is introduced, the galvano- bobbins of long wire, the ends of which are connected with a meter indicates an instantaneous induced current in the wire, delicate galvanometer, at a sufficient distance to be withdra wa the ir verse of that which exists about the bar, comparing the from the action of the magnet. bar .. a dynamical cylinder, as is done in the theory of
With revolving plates formed of magnetic or diamagnetic Amère.
metals the galvanometer always indicates the formation of 2. Directly the bar is removed, the needle of the galvano: Verdet, the observed differences depend solely upon the con
induced currents of more or less intensity. According to M. meter, which was brought back to zero, indicates a direct induced current,
ductibility of the metals, and not at all upon their diamagnetic We may also establish the inductive influence of magnets
power, as some philosophers have supposed. by the following experiment :--Place a bar of soft iron in the which a voltaic current passes is wound about itself like a
The Induction of a Current upon itself.- When the wire along single wire bobbin, and bring a strong magnet suddenly near helix, it is observed that the spirals of the helix react upon it; the needle of the galvanometer is then deflected, returns to zero directly the magnet is fixed, and is detected in the one another, so as to communicate more intensity to the curcontrary direction on its removal. The induction is here pro- example, nothing but a scarcely perceptible spark is obtained
In fact, with a Bunsen battery of several couples
, for duced by the magnetisation of the soft iron under the influence either by closing or opening a current, if the wire which conof the magnetised bar. The same effects of induction are obtained in the wire of an forming part of the circuit by holding an electrode in each
nects the two poles is short and not wound. Further, on electro-magnet by turning a strongly-magnetised bar rapidly hand, you feel no shock at all. On the contrary, if the wire round in front of the ends of the electro-magnet, in such is long and wound many times round itself, so as to form. manner that its poles act successively by influence on the two thick bobbin
, the spark dwindles to nothing on closing the branches of the electro-magnet ; or by forming two bobbins current, but acquires considerable intensity on opening the round a horse-shoe maynet, and passing a plate of soft iron current'; and if you form part of the circuit you feel a shock rapidly before the poles of the magnet. The soft iron, being which is more violent in proportion as the contact is more magnetised by influence, re-acts upon the magnet, and induced completely established with the hands. currents are successively produced in the wire in contrary
Mr. Faraday has shown, by means of the galvanometer, that directions. Induction by Magnets in Bodies in Motion.---M. Arago, in 1824,
these phenomena are owing to an instantaneous current
, called first observed that the number of cscillations made by a
an extra current, which is produced in the wire connecting needle in equal times, when it is deflected from its position of in the same direction as the principal current. M. Abria
two poles at the moment when the connection is broken, and certain metallic substances, and particularly red copper, which found that
the intensity of the extra current is equal to abusi is capable of reducing the number of oscillations from 300 to 72 of that of the principal current. fact not less unexpected, that of the tendency of a copper you introduce a bar of soft iron within the bobbin, or, white
The effects described above acquire still greater intensity i plate in motion to make a magnetised needle revolve. To establish this phenomenon, arrange a moveable metallic bobbins of an electro-magnet.
comes to the same thing, if you pass the current through
This also is a phenomenon disc on a vertical axis, and cover this disc with a glass bell, in owing to the reaction of soft iron when its magnetisliste which a magnetised needle is suspended by means of a fine thread. The needle must be separated from the disc by a thin membrane , in order that the motion of the air may not
be instantaneous, induced "Currents
, by their is
Induced Currents of Different Orders.- In spite of their being transmitted within the bell. If the disc is subjected to a slow Huence upon closed circuits, give rise to fresh induced current and uniform motion, the needle is deflected in the direction of these again to others, and so on, in such
a manner as to pra the motion, and stops at twenty or thirty degrees from the duce induced currents of different orders. the disc. But if this rapidity increases, the needle is at last of New Jersey, are established by making a series of bobbins a
These currents, which were discovered by Professor Henry, describes an entire revolution, and follows the motion of the round itself in a spiral in the same plane, like that represented disc the dise, and varies very much with the nature of the disc
. in contrary directions, and
that their intensity decreases i The effect decreases with the distance of the needle from that the currents then produced in the bobbins are altemately The greatest effect takes place with metals; with wood, glass, water, etc., it is nothing. 'Mr. Babbage and Sir John Herschel proportion as they are of a higher order. have found that, representing the action of a magnet on a copper disc by 100, that upon other metals is represented by the
APPARATUS FOUNDED UPON CURRENTS OF
INDUCTION. following numbers : zinc, 95 ; tin, 46 ; lead, 25; antimony, 9; bismuth, 2. Lastly, the effect is greatly weakened if there are breaks of continuity in the disc, especially in the direction an apparatus, by means of which all the effects of currents
Clarke's Apparatus.—Mr. Clarke, of London, has constructed perceptibly regains the same intensity, if the breaks are united very powerful collection of horse-shoe magnets, fig. 461, fastered
M. Arago gave no explanation of these phenomena. It was electro-magneth B, moveable about a horizontal axis, lo Mr. Faraday who, in 1832, first showed, by means of the bobbins are formed upon two soft iron cylinders, bound at al galvanometer
, that they were owing to currents of induction end by a plate v of soft iron, and at the other by a similar developed in the discs by the intluence of the magnetised plate
of brass. These two plates are fastened to a copper afie needle? The same philosopher maintains, that the magnetic ac- | terminated at one extremity by a cylinder g i, and at the others nion of the earth produces similar electric currents in metallic by a pulley, to which motion is communicated by means of a discs in motion, so that we may say that all metals in motion leather strap passing round a large wheel r. on the surface of the globe are traversed by currents of induction,
Each bobbin is formed of a very thin copper wire, covered action of metals in motion have been studied by several philo- l of the wire of the bobbin'e, and the two other ends terminado Since then, the phenomena of induction produced by the
with silk and making as many as 1,500 turns. One end of sophers both in France and in America. In making their lin a copper ferule q, which is fastened to the axis, but isolated
from it by a cylindrical ivory envelope. Care must be taken in two cylinders p and p' held in the hands. Then every time that the currents induced in the ends which join, be in the the current is interrupted, an instantaneous extra-current is same direction, which is effected by winding the wires upon produced in the circuit formed by the wires np, rp', and by the the two bobbins in contrary directions.
body, and this extra-current gives a violent shock, which is When the electro-magnet is turned, its two branches are
Fig. 463. magnetised under the intluence of the magnet a alternately in contrary directions, and in each wire a current is induced which changes its direction every semi-revolution. To follow these currents in their progress, it is necessary to remember that the two ends of the wire which terminate at the ferule I give a current in the same direction, and it is the same with those which join on the axis. Now in front of the ferule & there is a second ferule o, formed of two equal pieces, isolated from one another, but one connected with g and the other with the axis. It follows from this, that during the revolution of the electro-magnet, each half of the ferule o represents a pole which changes its sign at each half revolution. From the two pieces o the current passes on to two strips of brass renewed at each half revolution of the electro-magnet, and its 6 and «, fastened to two copper plates r and n. By this intensity increases with the velocity of the rotation. Further, arrangement, the current in each strip b and c is constantly in the muscles contract with such force that the will has no the same direction. In fact, the strip o, for example, touches power over them, and you cannot open your hands. With an the two pieces o successively; it is therefore successively in apparatus well constructed and of large dimensions, it is im. communication with the axis and with q, and consequently possible to bear the duration of the shock; whoever attempts with two ends of the wires and then with the two others. to persist is thrown down, rolls on the ground, and is soon But the wires being wound in a contrary direction, when the overcome by the painful sensation.
bobbin B' takes the place of B, the current of the ferule q, as With Clarke's apparatus, all the effects of voltaic currents
Fig. 464. first, it must be traversed by a current in the same direction,
With the two strips b and e alone, the two contrary currents which proceed from the two pieces o could not unite ; but this is accomplished by means of a third strip a and two appendages i, only one of which is visible in the figure. These two appendages are isolated from each other on an ivory cylinder, but are respectively connected with the pieces o. Every time the strip a touches one of these appendages, it is in communication with the strip b, and the current is closed, for it passes from b to a, then reaches the strip e through the plate n. On the contrary, as long as the strip a does not touch one of the appendages, the current is broken.
At the moment when the current is interrupted, violent
two long copper wires, coiled in a helix and terminating The strip a is then suppressed, the current being closed by the