417 



DECIMAL KK.UTIONS. 



l.INATION OF THE MAGNETIC NEEDLE. 4 is 



that certain written law* should be framed, to which every 

 jtbea. without any distinction, should be subject A commission of 

 three members was appointed to visit Athens for the purpose of 

 getting a copy of Solon s bws, and making themselves acquainted with 

 the institution, of other Greek states. (Liv. iii. 31.) The commia 

 tracers having returned at the expiration of two years, the tribunes 

 immediately called for the new code. For this purpose another com- 

 mission, consisting of ten members, was named by the oomitia centuriata. 

 Uncontrolled power, both administrative and judicial, without any 

 appeal, and accompanied with the suspension of all other magisterial 

 offices, including the consuls and tribunes, was conferred on them. 

 The names of the ten commissioners are recorded In Livy (iii. 33) and 

 Dionvwu. Halicamasmia (' Antiq. of Rom.' xi. 56). Appius Claudius 

 was the leading member of the ten ; he was the soul of the commission, 

 and directed all the business. The decemvirs conducted themselves 

 with great moderation and justice. On the expiration of their year of 

 office, they had framed a body of laws, distributed into ten sections, 

 which were approved by the senate and the comitia, and engraved on 

 ten tables of metal 



As the new laws seemed imperfect in some respects, a new com- 

 mission was named, at the he.ad of w h ieli was the same Appius Claudius 

 (Liv. iii. 35). But the decemvirs now began to behave in a very 

 different manner ; they became real tyrants, and formed a most pernicious 

 oligarchy. They framed, however, several new laws, which were 

 approved by the centuries and engraved on two tables. Though their 

 commission and the year of their office were now at an end, they still 

 would not resign, but continued to hold their power in the year 447 

 B.C. and to exercise it in a most arbitrary manner. Appius Claudius, 

 by a most unwarrantable decision, declared Virginia, the daughter of 

 Virginias, an officer in the Roman army, a slave, because she had 

 refused to listen to his dishonourable proposals. Virginias, the father, 

 to save his daughter from violation, murdered her in the public place, 

 and, with the bloody knife in his hand, called on the people to take 

 vengeance on their oppressors. Both the citizens resident in Rome 

 and the army united themselves to overthrow the tyrannical power of 

 the decemvirs, who were forced to abdicate, and the ordinary magis- 

 trates were re-established. Appius Claudius was put in prison, where 

 he died. 



The ten tables of the former and the two of the latter decemvirs 

 together form the laws of the twelve tables. 



J. lirrrmriri litiliui judicandii, that is, ten men for the purpose of 

 deciding suits, formed a court of justice under the superintendence of 

 the protor, which was established about B.C. 287. The establishment 

 of this body was caused by the great increase of suite, which rendered 

 it impossible for the prater to get through the business of his court. 

 As to the powers of these decemvirs, we have no distinct notices. 



3. Jkfrmriri merit fariundif, were an ecclesiastical college, the mem- 

 bers of which were elected for life. The care of the Sibyllige books 

 belonged to them, and they were consulted by them on important 



- 



4. /Vcrmriri ayrit diridundii, were a commission for the temporary 

 purpose of dividing lands among the colonists when a new colony was 

 to be established. 



DKCIMAL FRACTIONS. [ARITHMETIC; FRACTIONS.] 

 DECIMAL NOTATION. (ARITHMETIC; NCMKHATIOX.] 

 DECIMAL SYSTEM OF WEIGHTS AND MEASUIIIN 

 [WEIOHTH AXD MEASURES.] 



|ii:<'LARATION (declaration, in law, is the statement of his case 

 by the plaintiff in an action at law : in a real action it is properly 

 called a count (narratio). It corresponds to the bill in chancery, the 

 libel in ecclesiastical courts, and the petition in the court of divorce. 



iso.] 



DECLARATOR, ACTION OF, a form of procedure peculiar to 

 the Court of Session in Scotland. Its name explains its nature, which 

 is an action to have it judicially declared that a certain right exists, 

 with reference to property, or that a certain character, as, for instance, 

 husband or wife, or heir or trustee, exists in a particular person or 

 persons. It is not necessary that the party who brings the action 

 should demand any immediate service from the law, or that there 

 should be any adverse party. It may be raised by jtcrsons in doubt 

 bow they ought to act to avoid the consequence of a breach of the 

 law, and thus it is frequently hod recourse to by public officers. A 

 person whose legitimacy is questioned, though no one may be at the 

 moment denying his right to possess any property of wh'ii h illegiti- 

 macy would deprive him, may bring an action of declarator of marriage 

 and legitimacy to have his claim judicially established. The prin- 

 ciple of the declaratory conclusion is often admitted into other actions 

 where there are many complex claims. The court lays down cer- 

 tain rules, applicable to the circumstances, by which the claims of 

 individual parties shall in the ultimate decision be tried. The action 

 of declarator has been applied to many useful purposes, but it is 

 likewise, like some similar forms of procedure in chancery in England, 

 capable of abuse. 



It has been proposed to vest a jurisdiction similar to that thus 

 exercised by the Scottish courts, in the Court of Chancery ; but the 

 proposal has not yet assumed sufficient shape to permit of its forming 

 the subject of legislation. The Court fnr Divorce and Matrimonial 

 Causes has, however, by a recent statute, been empowered to declare 



the Malta of persons being or claiming to be natural born subjects of 

 the Crown ; by establishing their legitimacy or the validity of the 

 marriage of their parenta. (21 & 22 Viet. c. 83.) 



DECLINATION. When a star is not in the equator, the angle 

 made by two lines drawn from the spectator's eye, one to the star, the 

 other to the nearest pole, is called its polar distance. The complement 

 of the polar distance, or the angle subtended by the star and tin- 

 nearest point of the equator, is the declination of the star. It is called 

 north or south according as the star is north or south of the equator. 

 The declination (it is becoming very common to use the polar distance 

 in preference) and the right ascension [AactxsiON, RIGHT] are the 

 usual co-ordinates to which a star's place is referred. Confining our- 

 selves here to declination, we must merely remark that the effect of a 

 diminution in declination is to bring the star nearer to the . 

 and its time of appearance above the horizon nearer to twelve I 

 The length of a star's (or of the sun's) time above the horizon is found 

 as follows : Multiply together the tangents of the latitude of the place 

 and of the declination of the star. If the answer be greater than 

 unity, the star is too near the north pole to set, or too near the south 

 pole to rise (according as the declination is north or south) ; if equal 

 to unity, the star grazes the horizon at the north (or south) jn >in 

 does not set (or rise) ; if less than unity, find the augle which has the 

 preceding product for its cosine, convert it into time at the rate 

 to an hour, and the defect from twelve hours is the half of the duration 

 required, expressed in sidereal time. 



DECLINATION OF THE MAGNETIC NEEDLE (or Variation of 

 the Magnetic Needle), is the angle which the horizontal needle make! 

 with the geographical meridian of any given place. 



It has been usual among European writers to refer the discovery of 

 the declination or variation of the needle to Columbus, on his first 

 voyage of discovery in 1492. This opinion rests entirely on the testi- 

 mony of the son of that great navigator, who states the circumstance 

 in the life of his father, with considerable probability of its being a real 

 case. It is however hardly to be conceived, that the compass should 

 have been in use amongst the enterprising sailors of Kuro|>e, upon 

 voyages so extensive as were then frequently undertaken, without <!,. 

 circumstance being not only observed by some, but known to all who 

 were engaged in maritime affairs. At all events, it appears from 

 various printed works and manuscripts to have been familiarly known 

 very soon afterwards to all the commercial nations of Europe. 



When it was found that the needle declined from the meridian by 

 different quantities in different places, it was still assumed that at each 

 given place the declination was constantly the same. In 1 581 Bin 

 published his ' Discourse on the Variation of the Compass,' in which he 

 states as the result of numerous observations, that the declination at 

 Lhnehouse was 11 15' E ; but in 1633, Gillebrand, the ( irexham pro- 

 fessor of geometry, found by careful observations that it only amounted 

 to 4 5' E. It has indeed been stated by Bond, that the variation of the 

 declination was first discovered by Mair, and secondly by Gunter ; but 

 as he gives us no authority for this assertion, we are unable to judge 

 of its truth or falsehood. Bond was addicted to paradox, and his 

 statements should therefore be received with caution. 



Careful observations (subject however, to several sources of then 

 unsuspected error) have been made from that period down to the 

 present time, and they all concur in showing that this variation of the 

 declination is continually going on, though not with a uniform angular 

 motion. It was therefore inferred, that the needle would continue to 

 irvo] vi! round the horizon by slow degrees, till at last it came round 

 again to any given position ; and it appears to have been suspected by 

 some, that the irregularity of its indicated motions was only apparent, 

 and arising either from the imperfection of the instruments employed, 

 or the inaccuracy of the observations themselves. The scientific world 

 was, consequently, not prepared to expect the results of Major Sabine's 

 observations on the declination, and the truth which they unfolded, 

 when in 1818 he determined it to bo 24* SCK W., and four years after- 

 wards to have retrogaded to 24 12', at London. Subsequent obser- 

 vations, however, bear out this conclusion ; and not only do the obser- 

 vations made in this country, but throughout Europe, undeniably 

 establish the fact, that the western declination had about 1818 or 1820 

 attained its maximum value, and that the needle, instead of continuing 

 to gradually move round the points of the horizon, ix now returning 

 towards the geographical meridian. The general opinion is therefore, 

 that the needle performs a series of oscillations nn each side of tha 

 meridian, and after attaining its extreme limit returns again through 

 another slow oscillation. As no easterly declination equal in quantity 

 to the recent westerly maximum value has been observed with care, 

 we are left only to conjecture on this point. If, indeed, we adopt this 

 hypothesis, and take Bond's authority for the declination Iwing in 

 1657, we ought to expect on such an hypothesis that it will be again 

 in 1979, and attain it* greatest easterly value in 2140. We H 

 we confess, very devoted believers in the opinion that its oscillations 

 are regular; and we think we could furnixh i-trong reasons for our 

 scepticism on this head : but while FO few steps have been made 

 towards a satisfactory theory of terrestrial magnetixm, it would be rash 

 to affirm that conclusive reasons can be given for either one opinion or 

 the other. At all events, the popular hypothesis depends entirely on 

 an analogy supposed to hold true between the pendulum and the mag- 

 netic needle, in a case where the analogy is unphilosopliically .-<: 



