the National Indoor Baseball Association of the gard the condition and make payment to the United States govern the game. indorsee or his transferee, whether the condition has been fulfilled or not. This changes the old rule, under which an acceptor or maker paid a bill or note with such an indorsement at his INDORE, in-dōr'. A native Mahratta State of Central India (Map: India, C 4). It is traversed from east to west by the Nerbudda River, and also by the Vindhya Mountains, their loftiest point within its limits being 2500 feet above the sea. Valuable timber is found in the forest; and wheat, rice, tobacco, sugar-cane, cotton, poppy, etc., are cultivated. Opium is one of the chief manufactures. The Bhils, one of the wildest and most savage of the aboriginal tribes of India, inhabit Indore. Besides the capital of the same naine (q.v.), the principal towns are Rampura, Mehadpur, Bhanpura, and Mhow. Area, 8400 square miles; population, in 1891, 372,800; in 1901, 333,000. The Mahratta ruler bears the name of Holkar (q.v.), whence the State is sometimes called the Holkar's Dominions. INDORE. The capital of the native Mahratta State of the same name, India, situated on the left bank of the Kuthi (Map: India, C 4). It is about 2000 feet above the level of the sea. Indore was founded in 1767, and contains the palace of the Holkar, a college, and mint. has a modern drainage system, and a good watersupply, and maintains a public lighting plant, market, reading-room, and dispensary. It has manufactures of cotton and a considerable grain trade. A suburban district, assigned by treaty, contains a British residency, the seat of an agent and his staff, and the Government opium depot of the Central Provinces. Population, in 1891, 92.300; in 1901, 86,200. It INDORSED, or ENDORSED. See HERALDRY. INDORSEMENT (from ML. indorsare, to indorse, from Lat. in, in + dorsum, back). In its broadest sense, any writing on the back of an instrument. As a technical term of the law merchant, it denotes the writing of the holder's name upon a bill of exchange, check, promissory note, or other negotiable instrument, on transferring it to another. While this writing is ordinarily on the back of such an instrument (whence its name), it is equally effective if made on its face, or on a paper annexed to the instrument. In order to convert the writing into a contract, it must be delivered with the intention of giving effect thereto; or it must find its way into the hands of a bona-fide holder. The contract obligation of an indorser is to pay the indorsed instrument, provided payment is duly demanded, and payment is refused, and due notice of the dishonor is given to him. If the payee or holder simply signs his name, the indorsement is said to be blank, and the subsequent holder may fill out the indorsement to any one. A special indorsement is one which specifies the person to whom, or to whose order, the instrument is to be payable, e.g. 'Pay C. D. or order. (Signed) A. B.' When personal liability as indorser is to be avoided, the words 'without recourse' are added. Such an indorsement does not prevent the further negotiation of the instrument, or cast any suspicion upon its validity. A similar restriction is made in England in the case of checks by crossing them. (See CHECK.) One which limits further negotiation is called a restrictive indorsement, e.g. 'Pay Corn Exchange Bank only. It is provided by modern legislation that when an indorsement is conditional, a party required to pay the instrument may disre peril, if the condition was not fulfilled. That was thought to be unduly hard upon the party required to pay. See BILL OF EXCHANGE; CHECK; NEGOTIABLE INSTRUMENT. IN'DRA. The great national god of Vedic India. Although Indra lost his supremacy through the rise of Brahma, Siva, and Vishnu, he is still preserved as a figure in the Hindu pantheon. As represented in the Veda (q.v.), he is primarily the god of the lightning and thunder, with the attendant phenomena of the storm, wind, and rain; by vanquishing the demons of drought and darkness he restores the sun to the sky, the light of dawn, and the day. The realm of his activity is the atmosphere; and the many hymns of the RigVeda that are devoted to his praise-far outnumbering those to any other god-are rich in meteorological imagery and poetic allusions to natural phenomena. Armed with the thundercopious draughts of intoxicating soma, his fabolt (vajra), his special weapon, and inspired by vorite beverage, he goes forth to do battle with the demons, especially Vritra, who, wrapped like the waters as prisoners. One of the hymns that a choking serpent about the clouds, has shut up describes this battle and the god's triumph over the dragon (Rig-Veda 1.32) is an epic in miniature. As the god of battles, Indra is looked upon in the historical hymns of the Veda as the royal patron of the victorious Aryans in their conflicts with the aboriginal inhabitants of India. His supremacy during the whole Vedic period is unquestioned; the more ethical and transcendental Varuna is no rival to his prowess. In the later mythology a change takes place; Indra gradually sinks to a secondary rank among the gods. His installation as god of the lesser divinities is described in the Aitareya-Brāhmaṇa ; and from that time onward he becomes rather a figurehead in the pantheon, and the type of a mortal king, than the former supreme lord of heaven. The Epic and Puranic periods distinctly show that he has ceased to enjoy the worship accorded him in Vedic times. He remains ruler of the atmosphere, it is true, and one of the eight world-guardians, regent of the eastern quarter of the sky, wielding his thunderbolt and sending down rain, but his real power is gone. Instead of descriptions of him as the great god of battles. praises are lavished on the delights of his paradise, Svarga, with its heavenly musicians and enchanting nymphs, the Gandharvas and Apsarasas, and all the joys of this happy abode of the gods and faithful worshipers. Like the later writings. the epics bring to view the sensual side of Indra's character in his amours with Ahalya, the wife of a sage -a bit of scandal as old as the Brahmanas. In consequence of the curses of the outraged seer, the god was doomed to lose his virile power; the conqueror Indra ceases to be invincible, even a son of the demon Ravana vanquishes him, as told in the Ramayana, and wins the title Indra-jit, victor over Indra, for his prowess. The Purānas likewise describe him as worsted by the rising god Krishna, an incarnation of Vishnu, and they name various successors of Indra as INDRA. rulers in the different manvantaras, or ages of INDRANI, in-drä'nê. A name of the wife of INDRE. A central department of France, the western portion of the old Province of Berry, lying immediately south of the Department of Loire-et-Cher. Area, 2666 square miles, of which about four-fifths are in tillage and pasture Population, in 1896, (Map: France, H 5). 289.206; in 1901, 288,788. The chief rivers are the Indre, the Vienne, the Creuse, and its tributary, the Anglin. The surface is for the most part flat, and the land is generally fertile, pro ducing large crops of wheat and barley. The principal resources of the department are its vineyards and its flocks. The principal manufactures are woolen and linen cloths, hosiery, scythes, paper, and porcelain. Iron-mines are worked. Capital, Châteauroux. INDRE-ET-LOIRE, å lwär. An inland department of France, part of the ancient Prov ince of Touraine, lying northwest of the Department of Indre (Map: France, G 4). Area, 2377 square miles, of which more than one-half is arable; population, in 1896, 337,064; in 1901, 335,541. The department is watered by the Loire, the chief river, and by its tributaries, the Cher, the Indre, and the Vienne, all of them navigable. In the south the surface is hilly, but in the other districts it is undulating and fertile. Cereals are grown, but wine is the most imThe chief manufactures are portant product. bar iron, woolen cloth, silk, rope, paper, and leather. Capital, Tours. INDRI. A large, monkey-like lemur (Indris brevicaudata), of Madagascar, which is regarded as the most highly organized of the tribe, and differs from other lemurs in several important particulars, such as having only 30 teeth, the INDUCED ELECTRIC CURRENTS. INDUCTANCE. See INDUCTION. See See INDUCTION (Lat. inductio, inference, from inducere, to lead in, from in, in + ducere, to lead). A form of the logical process of discovering the general character of individual pheIn order to understand any fact or nomena. event, we need not only to be able to tell of its sensible qualities or constituents, but also to know what identity (q.v.) it has with other facts or events. Such an identity is a general character, or, as it is called in logic, a universal. When in the case of several objects we discover an identity in color or shape, we perform the act of conception. If, using some already discovered identity between some objects as a point of departure, we assume some other iden tity to exist between the same objects, we are said to generalize or to make an induction. Induction may thus be defined as the univer salizing of perceived relations or connections between objects. Among these relations one of the This universalizamost important is that of antecedence and con(See CAUSALITY.) tion is corrected or confirmed by further observation of these connections in other individual cases until at last often a valid judgment asserting unconditional connection is reached. A valid induction is one which, starting from particular observations, thus reaches a valid universal judg Scientific inductions do not differ in ment. sequence. principle from the naïve inductions we have already described; the difference is one of degree, not of kind. Looking now at inductions ascertained to be valid, we discover three stages in the process of The first stage is At this point arriving at certified results. called preliminary observation. actual coexistences and sequences or other relations are observed and form the data for the induction. The second stage consists in the generalization of some actually ascertained coexistence or sequence, or other relations. This is induction proper. The third stage is verification, the correcting or confirming of the validity of the generalization by further observation. Frequently the term induction is used to include all these three steps; in this case the second step is called generalization. Let us now take up these three steps in order. I. Preliminary. observation may be quite casual and accidental, or it may be intentional. A person may happen to see some connection between phenomena, or he may be intently lookIn the latter case, the ing for connections. observer may simply look at things as they offer themselves to his notice, or he may set about to interfere with the spontaneous course of events in order that he may the better observe the connection. The latter sort of observation is called an experiment. When experiment is possible, it is usually of great assistance in collecting data for generalization. Indeed, almost all the great advances in modern science have been due to experimentation rather than to mere observation. In intentional observation, whether it be simple or experimental, it is extremely important for the observer to know what he is to look for. Not every detail in the complex of details under observation is pertinent to the matter in hand; and yet no a priori rules can be given to direct an investigator. Much depends on experience and skill not subject to rules. But by analyzing successfully conducted inductions, logicians are able to formulate several important rules of procedure, which thus are a posteriori. For our present purposes we can do no better than quote John Stuart Mill's canons of induction. These state the conditions under which generalization may be made. Hence the observer should be on the watch for the occurrence of these conditions. The canons are as follows: First Canon, for the Method of Agreement: If two or more instances of the phenomenon under investigation have only one circumstance in common, the circumstance in which alone all the instances agree, is the cause (or effect) of the given phenomenon. Second Canon, for the Method of Difference: If an instance in which the phenomenon under investigation occurs, and an instance in which it does not occur, have every circumstance in common save one, that one occurring only in the former, the circumstance in which alone the two instances differ, is the effect, or the cause, or an indispensable part of the cause, of the phe nomenon. Third Canon, for the Joint Method of Agreement and Difference: If two or more in stances in which the phenomenon occurs have only one circumstance in common, while two or more instances in which it does not occur have nothing in common save the absence of that circumstance; the circumstance in which alone the two sets of instances differ, is the effect, or the cause, or an indispensable part of the cause, of the phenomenon. Fourth Canon, for the Method of Residues: Subduct from any phenomenon such part as is known by previous inductions to be the effect of certain antecedents, and the residue of the phenomenon is the effect of the remaining antecedents. Fifth Canon, for the Method of Concomitant Variations: Whatever phenomenon varies in any manner wherever another phenomenon varies in some particular manner, is either a cause or an effect of that phonomenon, or is connected with it through some fact of causation. These are statements of the conditions under which scientific men make inductive inferences. Hence in our observations for the purposes of induction we should keep the following questions in mind: Is it the case that any instance in which the phenomenon under investigation occurs, and any instance in which it does not occur, have every circumstance in common save one? Is it the case that two or more instances of the phenomenon under investigation have only one circumstance in common? Is it true that two or more instances in which the phenomenon under investigation occurs have only one circumstance in common, while two or more instances in which it does not occur have nothing in common save the absence of that circumstance? Is a part of this phenomenon under investigation known to be the effect of certain causes? Does the phenomenon under investigation vary in any manner whatever whenever some particular circumstance varies in some particular manner? In case any of these questions can be answered in the affirmative, au induction may be made. It must not, however, be supposed that an investigator sets about his work with only such general clews as are furnished by these questions. In any particular investigation, a knowledge of exactly what has already been done by previous workers is indispensable. If he has this knowledge, the investigator is in a position to ask much more definite concrete questions than the five we have just mentioned. But, however much more definite his problem may be, it may always be reduced to general expression, and when so reduced it will assume the form of one of the five questions stated above, which give the headings for the treatment of the methodology of observation. Any more specific methodology can be worked out only on the basis of the practiced experience of the expert in any particular line of research. II. It has already been said that when any one of the five questions given in the last paragraph can be answered in the affirmative, we universalize the actually observed relation between phenomenon and circumstance. But now it will probably be asked what warrant there is for this universalization. The answer is somewhat as follows: To universalize is an instinctive tendency of thought. The child 'jumps at con clusions' in very much the same way as the kitten jumps at a moving string. What the child does, the ordinary adult also does, and unless corrected by experience the probability is that every one would generalize every observed relation. But experience does check the tendency in a measure. The child who generalizes the observed connection between shape and reboundingness, or color and reboundingness, comes by later experience to find that his generalization is invalid. The truth of the universal judg ment implied in his expectation is not borne out by later developments. But he is nothing daunted. He proceeds to generalize some other observed connection until at last he gets a general law which is uncontradicted by experience, and which he therefore accepts as true. The first generalizations are naïve, instinctive attempts to find uniformity in the world of experience. The attempt in any particular direction may be baffled, but only to be followed by an attempt in another direction. In other words, some attempts fail and others succeed. To succeed is to find that subsequent experience conforms and continues to conform to the expectation aroused by previous experiences. To fail is to find that subsequent experience disappoints this expectation, while in either case the expectation is, from the point of view of logic, an unreflective generalization. In later life consciousness becomes reflective; it looks back upon its own processes and finds that in cases of successful generalization certain conditions are present, while in cases of failure these conditions are absent. The same instinctive generalizing tendency which led to the generalization of the earliest connections discovered, now leads to the generalization of the connections between successful generalization itself and the conditions under which the success is achieved. These latter generalized connections are logical laws of thought. We now are in a position to see that there are two kinds of laws of thought, logical laws and psychological laws. The psychological laws are those which express the modes of thought-behavior, whether the results of the behavior be intellectually satisfactory or not. The logical laws express the conditions under which the results of thought-behavior are intellectually satisfactory to the thinker. Thus it is a psychological law that an immature thinking consciousness generalizes instinctively, i.e. with out any foresight of the results to be gained; it is a logical law that if the generalization is to be valid it must be made only under certain conditions, given in the five canons mentioned above. This logical law is itself validated by the fact that it is a generalization made in conformity with the law of which it is itself the expression. In other words, it is self-consistent, and also consistent with all the known facts. A more stringent test of the validity of any law has never been conceived. If now it is further asked whether we know that the thought which conforms to the laws of thought thus discovered will continue to be successful in the future as it has been in the past, we can answer by saying that we have only one plausible reason to suppose it should not be successful, while every other reason that we know would lead us to believe that it will be successful. That one exception is the fact that in past experience when we thought that we had discovered laws, we often found that we were in error. Hence, it may be reasoned, it is possible that we may be in error now as to the logical laws of thought. But this argument has not the force that at first sight we might be tempted to ascribe to it. If we know that in the past we thought wrongly in many instances in which we thought that we were right, and if we now generalize this knowledge and say that therefore on the same principle we may now be in error, and may always be in error, we are making a naïve, uncriticised in duction; and such inductions our past experience has proved to us to be very precarious. We can criticise the naïve induction when we discover that in the past any supposed knowledge turned out to be error only in cases which did not conform to certain conditions. If now our generalization as to the valid laws of thought is made in conformity with these conditions, lack of conformity to which made other inductions invalid, then the invalidity of those other inductions is no reason for attributing invalidity to these laws of thought. Past errors in induction should indeed make us very circumspect. We should use our utmost endeavors to avoid the causes which misled us; but having avoided the causes, we need not be timid as to the validity of an induction which in the past has never been impeached by experience, but, on the contrary, has been verified time and time again. A persistent objector may still argue that the fact of our having made errors in the past is still a good reason for doubting the validity of all inductions, and therefore for doubting the validity of the laws of thought which we have discovered by induction. A man who argues thus forces us to resort to a valid form of the argumentum ad hominem. (See ARGUMENT.) He obliges us to remark that he assumes for the purposes of his argument the validity of the law he is assailing. What is an appeal to the fact of past error in proof of the fallibility of all laws of thought? It is nothing but an induction from past experience. The correctness of the conclusion of this induction would carry with it the invalidity of all argument by induction, and therefore the invalidity of this argument which seeks to prove by induction the correctness of the conclusion. Here as elsewhere (see KNOWLEDGE, THEORY OF) we see that one cannot reason against the laws of reason without putting one's self out of court. III. Verification of an induction consists in testing it in new instances. Any newly made induction is presumably based on a limited experience and it needs to be examined in its bearings upon other parts of experience. The question in the mind of a person verifying an induction is this: Does the universalized relation prove its universal character in all our experience so far as this experience is pertinent to the relation at issue? This question can be answered only by looking at our past experience and by getting further pertinent experience. No verification of a true universal can be exhaustively completed; but, as we saw under II. above, it may be practically conclusive. There may be no reason left for doubting a proposition except the bare possibility that it may not be true in cases as yet beyond our ken, but a bare possibility is always an unreasonable possibility. The relation of induction to deduction is treated under DEDUCTION. The question whether any general proposition can be arrived at without induction has often been affirmatively answered. A PRIORI.) But that answer is incorrect. KNOWLEDGE, THEORY OF.) For instance, the geometrical axiom that things equal to the same thing are equal to each other is derived from experience by induction. It is first seen in individual instances that individual things, equal to the same individual thing, are equal to each other. This relation is then universalized. with the arithmetical judgment: Two and two are four.' Hegel and J. S. Mill are the great logical protagonists of this view. Mill's statement of the view is more familiar than Hegel's, but it is defective in that it is based on an atomistic view of experience (see ATOMISM), a view which makes against the validity of induction by reducing all induction to mere simple enumeration (inductio per enumerationem simplicem), or a bare telling off of isolated findings, and a summation of the results of these findings into a collective statement. (See (See So Consult the authorities referred to under LOGIC; especially to be named here are the logics of Hegel, J. S. Mill, Bain, Minto, Jevons, Ueberweg, Lotze, Wundt. Sigwart, Bradley, Bosanquet, Hibben, and Creighton, also Hobhouse's Theory of Knowledge (London, 1896). INDUCTION. If an electrified body is brought near an uncharged one--either conductor or non-conductor-the latter will exhibit electrical forces; it is said to be charged by 'induction.' In general, if a charged body is surrounded by a uniform medium, such as air, and if a body of upon these properties for each circuit and upon their relative positions. It can be shown that inductance plays the same part in the phenomena of electric currents that inertia or mass does in the motion of matter. The practical unit of induction is the henry (q.v.). any other material than that of the medium is introduced, thus making the surrounding medium heterogeneous, there will be induced charges on the body introduced. The question as to the character of the charges on this body and their distribution depends upon the relative electrical inductivity of the body and the surrounding meINDUCTION BALANCE. An instrument to dium. (See ELECTRICITY.) Similarly, if there determine the presence or character of a piece of is a magnet surrounded by a uniform medium, metal, which may be either concealed, as a bullet such as air, and if a body of a different kind of in a human body, or in the form of a counterfeit material from the medium is brought near the coin or alloy. It was originally devised by Dove magnet, it will exhibit magnetic forces and is in 1841, but was improved and constructed in a said to be magnetized by induction. The charac- serviceable form by Hughes in 1879. It consists ter and distribution of this induced magnetiza- of two sets of induction coils in which the prition depend upon the relative magnetic induc- maries are connected together in a circuit that tivity of the medium and the foreign body. (See includes a battery and a microphonic or other MAGNETISM.) If the body which is introduced circuit-breaker, while the secondaries are in conis iron or any magnetic body, and if the medium nection with a telephone used by the observer. is air, the induced magnetization is such as to The current traverses the primary coils in opproduce attraction by the magnet; if bismuth posite directions, and the secondary coils are is introduced there will be repulsion. Electroso arranged that the sound of the microphone magnetic induction is the phenomenon observed or circuit-breaker is not heard, owing to the when the magnetic field of force included by a inductive effect being neutralized completely. If conducting circuit is altered in any way, viz. elec- a coin or other metallic substance is introduced tric currents are produced in this circuit. These into the vicinity of one of the pairs of coils, induced currents are due to the changing of the this equilibrium will be disturbed, as part of field of magnetic force, and are in such a directhe induction acts upon the metal and gives rise tion as to tend to neutralize the change; they to induced currents. This of course produces an last only so long as the field is changing. See audible sound in the telephone. The instrument ELECTRICITY. is also used to measure hearing, and it then is known as an audiometer, the perception of sound being tested by altering the positions of the coils. An arrangement of the induction balance was devised by Prof. Alexander Graham Bell to locate a bullet in the human body, and apparatus based on the foregoing principle was employed and numerous different forms made and tested. It was used in an attempt to discover the bullet by which President Garfield was killed, but the presence of the metallic mattress interfered with the operation of the instrument. Instances, however, of its successful use are on record. Consult: Bell, "Induction Balance," in American Journal of Science (New Haven, 1883); Hopkins, Experimental Science (New York, 1890). TUBES OF ELECTRIC INDUCTION are tubes which can be imagined drawn in the medium surrounding electrified bodies by choosing any small closed curve in this medium and drawing lines of force through each point of it. A hollow tube is thus made which has one open end on a positively charged body and the other on one negatively charged. If this tube is made of such a crosssection that it includes unit electrostatic charges as its two ends, it forms a 'Faraday tube.' TUBES OF MAGNETIC INDUCTION are tubes formed in the same manner in the field around magnets by drawing lines of magnetic force through the points of any small closed curve. Faraday conceived the idea of these tubes being continuous through magnets and all bodies, not ending on any surface; they form, therefore, closed circuits, like a rubber tube with the two open ends brought together. The tubes are conceived to be of such cross-sections that the number leaving a north pole of unit strength is 4π, where 3.1416. See MAGNETISM. Owing to an electric current in a closed circuit, there is a magnetic field of force inclosing it; the tubes of magnetic induction form closed curves around the conductor. The coefficient of self-induction, or the inductance, is the number of these tubes threading through the circuit when there is a unit current in the conductor. Some of these tubes of magnetic induction may also in their paths pass through a neighboring closed conducting circuit, and the number of those tubes which do so when there is a unit current in the first circuit is called the coefficient of mutual induction of the two circuits. It may be shown that if there is a unit current in the second circuit, thus producing tubes of magnetic induction of its own, the number of these which thread the first circuit is the same as in the last case. The coefficient of self-induction depends upon the shape of the circuit, the number of turns of the conducting wire, and on the surrounding medium, and the coefficient of mutual induction depends |