INARCHING. 



INCLOSURE. 



HI 



INARCHING. 



The luminous glow of a iolid or liquid body 

 intensely ignited. [IGNITION.] 



IN. KN DIARY. (ABos; LAW, CRIMINAL.] 

 I X < ' KST. During the Protectorate incest and adultery were made 

 capital offences, but at the Restoration this law was not renewed. 

 Incest in England is now punishable only by the ecclesiastical courts, 

 according to the canon law, which determines what kind of sexual 

 connection U incest. It may be committed either by married persons 

 or persons unmarried. Adultery may be incest, and fornication may 

 also be incest; the legal notion of incest being founded upon the 

 degree of consanguinity or affinity between the parties. 



The term U derived from the Roman Incestum, which is the same 

 as Non Castum, " not pure," and in ite most general sense signifies 

 any offence against positive morality, or religion. Persons within 

 certain degrees of consanguinity could not contract a marriage ; if they 

 did, or lived together as man and wife, such a connection was called 

 incestuous (Incestae Nuptiae). The affecting to marry was not bow- 

 ever necessary to constitute Incestum. It existed whenever there was 

 sexual connection between a man and woman who were incapable of 

 contracting marriage. If the parties were capable of contracting mar- 

 riage, the connection would be Stuprum, which in iU limited sense, 

 corresponds to fornication. 



The Romans do not appear to have had any direct legislation on this 

 subject till the Imperial period, and the rules of law that were in force 

 were founded upon positive morality and usage. The Lex Julia which 

 was enacted in the time of Augustus treated of incest only indirectly, 

 and so far as it concerned the object of that law, which was the 

 punishment of adultery. In some cases the punishment was capital. 

 (Diin. Casaius, Iviii. c. 22 ; Tacitus, Annul.,' vi. 19.) 



The subject of the Roman Incestum is treated copiously by Rein, 

 ' Criminalrechl der Rb'mer,' and with a reference to the numerous 

 authorities. 



INCH OF CANDLE. [AocrioM.] 



INCIDENCE, ANGLE OF, a term used in catoptrics, radiant heat, 

 Ac., to express the angle between the direction in which a line strikes 

 on a plane, and the perpendicular to that plane. 



I si 'INKKATION. An operation in organic chemistry, which has 

 for its object the separation of inorganic from fixed organic matters. 

 It consists in heating the organic substance to redness in a current 

 of air (in a muffle for instance) until all the organic matter is 

 consumed, the non-volatile inorganic matters are then left behind as 

 an ash. 



INCLINATION. [MAGNETISM.] 

 INCLINATION. The inclination of two lines U a phrase commonly 

 used for the angle which they make with one another. Thus, two lines 

 which make a very small angle are said to be at a very small inclination 

 to each other. Looking at the etymology of the word, and its use in 

 common language, it would seem proper to say that one line is without 

 inclination to another when the two are perpendicular, and that the 

 mailer the angle the greater the inclination. But custom has settled 

 otherwise, and has, in fact, made the word inclination synonymous 

 with angle ; while the term angle of incidence holds the place which, 

 according to etymology, belongs to angle of inclination. 



IN'i'l.lNKIU'l.AN'K. Among the mechanical powers, as they are 

 termed, meaning the contrivances by which pressure is advantageously 

 applied, the inclined plane has held a place in practice in every country 

 in which the arts have made any progress. But the introduction oi 

 this contrivance into the theory of mechanics dates from the time 

 of STKVIX, to whose life in the Bioo. Div. we refer for an account 

 of the very remarkable addition which he made to the first principles 

 of statics by means of the inclined plane. 



If a weight be placed upon a horizontal plane on which there is no 

 friction, it is obvious that the weight will be entirely supported, anc 

 that any horizontal pressure, however small, will cause motion. If the 

 same plane be made vertical instead of horizontal, the weight cannot 

 be placed upon it, for if the heavy body were made to touch the plane 

 and then left to iUelf , it would fall down the plane exactly in the same 

 manner as it would fall if there were no plane ; that is, supposing 

 there to be no friction. 



If the plane be made to assume an oblique or inclined position, the 

 effect produced will be intermediate between those of the preceding 

 cases. The weight will not rest, nor will it acquire velocity as rapidly 

 as when it falls freely. The reaction of the plane will counterbalance 

 a portion of the weight, as follows : Let A B represent a section of the 



parallel to A B. Then [CoMPOgmox] the pressure o v is equivalent to 

 he two pressures o w and w v, of which the former is destroyed by 

 he resistance of the plane, and the Utter only acts to propel the heavy 

 body down the plane. Now vwistovoaiBcistoAB; lhal is, a 

 weight placed upon an inclined plane U propelled down the plane by 

 such a fraction of the whole pressure of the weight as the height of 

 any section of the plane is of its length. 



If then it were required to draw the heavy body o up the plane, any 

 iressure exceeding vw would be sufficient for the purpose; and a 

 iressure equal to T w, applied in the direction A B, would keep the 

 weight at rest. 



If a body which is placed at B on an inclined plane be allowed to 

 'all to o, the velocity which it will then have, 

 md the time of describing BO, are determined as 

 follows : Lei B K be vertical, a M horizontal, and 

 o K perpendicular to B o. Then the velocity at u 

 ,s that which would be acquired by a body falling 

 freely from B to u ; and the time of describing B o 

 would be lhal in which a body falls freely from B 

 to K. From hence follows immediately Ihe remark- 

 able proposition lhal if any number of chords be 

 drawn from Ihe highest poinl of a vertical circle, 

 and if these chords be the sections of as many in- 

 clined planes, the times of falling down any two of 

 these chords are the same. 



The preceding results are obtained by applying Ihe 

 method explained in Ihe article FALL OP BODIES. Using the notation in 

 that article, and supposing 9 to be the angle by which the plane U 

 inclined to the horizon, the accelerating force which urges the weighl 

 downwards is g sin t. Consequently we have the following equations : 



e=yaine.t. 



2g sinfl. 



plane, and o a section of the weight. Let o v represent the magnitude 

 and direction of the weight, and draw o w and w v perpendicular and 



Here s is the length B a : and sinfl is B M. 



The preceding results suppose friction not to exist : now let there 

 be a friction, the proportion of which to the pressure ia the fraction t. 

 Then w representing the weight, the propelling pressure v w is w siu 6. 

 But the pressure on the plane, or ow, is w cosfl; consequently k 

 w cos is the amount of presssure down the plane which friction will 

 resist. If then Jt w cos 8 be greater than w sin 6, that is, if be 

 greater than tan 9, the weight will not move ; if t be equal to tan 8, 

 the weight will be just poised, and any pressure, however small, will 

 cause motion ; if k be less than tan 8, the weight will move downward* 

 with an accelerating force g (sin 0-!-t cos 9). 



There are many remarkable properties connected with the motion or 

 equilibrium of bodies on inclined planes ; but the preceding are those 

 which are most fundamental and most frequently required. 



INCLOSURE. The term inclosure is applied to the inclosing and 

 partitioning of lands in England and Wales, which are comprehended 

 under the general name of Commons or Common Lands. A knowledge 

 of the present condition of the lands comprehended under this term 

 enables us to form a better estimate of the state of agriculture in 

 England and its capabilities of improvement. We thus learn also 

 what was the general condition of the lands in England before inclo- 

 sures were made. 



It is necessary to define the terms Commons, and Commonable and 

 Intermixed Lands. Commons or Common Lands are lands in a state 

 of nature or waste, of which individuals have not the severally. Com- 

 monable Lands are those lands which during a part of the year are in 

 severally, that is, occupied severally by individuals aa their own, to 

 the exclusion for the time of other people. 



There U great variety in these coramonable hinds ; but they may 

 be divided into three classes, exclusive of wood-lands : First, there is 

 open arable and meadow land which is held and occupied by indi- 

 viduals severally until the crop has been got in. After the crop \\.\x 

 been removed, that is, during the autumn and winter, it becomes 

 commonable to persons who have severally rights in it, and tlu-v turn 

 on to it their cattle withoul any limit, or without stint, as it is t. 

 Thus there is a divided use in these open lands : individuals have the 

 exclusive right to the enjoyment of one or more of these stri| of 

 open land for a part of the year ; and during another pait of the year 

 all these individuals enjoy this open land in common. Second, there 

 is open arable and meadow land thai is held in severally dm M 

 part of the year, like the first class ; but after the crop in n -moved, it 

 is commonable not only to parties who have severally rights, but to 

 other classes of individuals : these lands are generally called Lammas 

 Lands. 



These commonable rights may belong to a particular class, as a body 

 of freemen, or to all landholders. There is great variety in these two 

 classes as to the severally holdings also. " There are many cases in 

 which the severally holding varies year by year. There arc in these 

 open lands whal is called a pane of land, in which there may be 40 or 

 60 ditterenl loU. Il is reported to be n ' an "Id military 



custom, when on a certain day the best man of the parish appeared to 

 take powession of any lot thai he thought fit ; if hi" right was called 

 in question, he had to fight for it, and the survivor took the first lot, 

 and so they went on through the parish. It often happens that in 

 these shifting severaltie* the ' lot one this year goes round 



the whole of the several lots in rotation ; the owner of lot one this 



