CATAUX8I. B00NAVKNTURA. 



CAVALLO. TIBKIUDa 



114 



Sevsral powerful barric.de. 

 tad carried in UM recular order of battlo. 

 i by lamartiiM. leading the attack of the 

 On the second day of the in.ur- 



MMWUdfaiUMPlMbOMfAiTMipta. On the second day of U icuur- 

 nitJn. Paris WM Jitltnifla . state of siege, and General Cevalgnae 

 WMtMMsatsdrJMtator.ell UMdvil and military power, being ooai- 

 sj.tM.ato kb oatrie. After tan days hud fighting, the oonteet 

 casae to M etri by UM defett of UM saarchbta The Ice. on both 



I .< 



wat innHlag: two renerab ware killed, four others mortally 

 fn all. tome 8000 persons were killed and 



and badlv wounded. 



d. and II 000 --* in tmesis No sooner bad be quelled this 

 a UM pascal bid down hb authority. The National 

 ,, rfated USB President of the Council, after which he 

 i one of UM candidates for UM new office of President of the 

 la tab contest be WM supported by 1,448,803 votes. On 

 UM Sad of December 1841 he WM arrested, but released after a short 

 aettaUpa; and be bu since then continued to reside undisturbed in 

 France, alUwofh be bu not given hb adhssion to the government of 



CAVALIfcRI. BCONAVENTIJRA. wu born at Milan in 1598, and 

 tarvd into UM order of Jesuit, at an early age. He wa afterwardi 

 nil II I r at Bobcat, and died then December 8, 1647. He WM a 

 papa of OeUbu, according to UM testimony of hi* friend Riccioli, who 

 profcasss Istsilf moon in^tHtd to his assistance in hU Undies. But 

 it b said UM* he did aot obtain the professorship at Bologna, in ipite 

 of the) stroaf reonBiinsndstioti of Galileo, until hu akill in astrology 

 i duly eertilUd He WM a victim to the gout both in hand 



UUabtd) B 



M I :.. 



rely to hb bed for twelve years 



hb death. Thar* b an Ooge of him by Krbi (quoted by 

 Umax. Iliac. Univ.'). All hb works were published at Bologna, 

 ~ eehio Ustorio,' Ac. 1681; 'Directorium Oenerale Urano- 

 1683; Ocomctria Indivbibilibus Continnornm,' ic. 1635; 

 TricononMtrb Plan* et Sphssrioa, 1 1685; Mtota Planetaria, 1 1640; 

 Exerritatione* ONB*trba Sex.' 1647. 



If we may jndge from a contemporary biographer, Ohilini, ' Teatro 

 d'Uoauni Lettcrati, 1 Caralbri (or Cavalerius, u hb name b usually 

 enjoyed a remarkable reputation in hb day. 

 descended to posterity solely through hb method of 

 miiritillm, one of UM prtdscsesors of the doctrine of fluxions, and 

 aateh [BABBOW, Lctntrrx ; DirrtBcmaL CALCULUS in ARTS AND 

 Dfr.l matt b* con*idered M one of the first attempt* at an 

 method of dealing with the difficulties of the solution of 

 i bad given the first example. Cavalieri considers a 

 of an infinite number of points, a surface of an 

 of Hnsi, and so on, M in the following sentence : 

 im est figure* plans* nobis ad instar tela parallel i. 

 i conoipiendM MM ; solids vero ad instar librorum, qui 

 petal bib folii* eoaoarvantur. Cum vero in teU aunt temper fib, et 

 in ttnrb sesspsr folia nomero finite, habet [babent] enim aliquam 

 i in figurb planb linese, in solidis vero plana numero 

 supponenda rant' Thb method, absolutely considered, 

 b t illative end even erroneous, but the error b of the same kind M that 

 of L*itiu. who considered a curve M composed of an infinite number 

 of infinitely small chord*, and a surface of infinitely small rectangles. 

 The error U both b one which does not affect the result, for tbb 



lit in using the simplifying effect of a certain 

 ton too early in UM process, by which the logic of UM inves- 

 may be injured, but the result b not affected. For instance, 



I. Let n 



< :. HMH 



na: the 



iam of all of which b i < + f) a, or ,! o, throwing away I MM 



, when a b infinite. But 1 a. Ha 

 Compare thb method (abiunl 

 the literal senu of the terms) 

 following. Divide UM bate (6) into a equal parts, each of 



watch b therefore -. Let UM perpendicular be , consequently the 



CBTabriat would oonaider a rbhUwgbd trbngb M follows, 

 b* UM aamber of points in the beet, then the perpendicular, al 

 points are ia arithmetical progression, 0, o, 4 a, Ac. . . . M 

 enniofanof whbhb, ( + !) a, oj 



b almiilj 1 bast . perpendicubr?' 

 MjahBoet aBfaliltjjjK'M te b, to 



with UM following. Divide UM bu, 



WMplbd by -, and ths sum of the whole being taken, 



S(S--V)-V *-*( !> 



Thb b the sum of UM inscribed rectangles, which approachM without 

 ttadttotlM area of UM trbngb M a b iaeneeed without limit But 

 It B|i|ii oiuBBt to I on tbe tame supposition ; whence , 6 p b the 

 ares ef UM trbngb. KHaer method, with caution, might be made to 

 rive tra* rasnrta, tod b an inullt^ibb manner ; but that of Cavalerius 

 b vary tobbct to error, and. we msy ssy, requires a knowledge of 

 method, to nnoVntand It Bat it b nevertheless the first 

 1 et genmlbttion, end ISTTM to illu.trate the position main- 

 r ns [BAkBowt UM* nelUier UM fluxions of Newton nor the 

 i ef LeibnJu wr* UM sctual m.tl.n 1. by means of which 

 Cskula. (M now known) wu made powerful 

 Cavabnas, with the methods of development ' of Newton, might have 



ssleMblml hb title to the invention. But hi* algebra WM very 

 imperfect, even for hi* day : we cannot see proof, in 1647, that he had 

 ever seen the writing* of Viet*, who dird in 1603. The celebrated 

 Quldinu* wrote against the method of indivisible, and wa* answered 

 by Cavabrius in the third of the ' Kxercitatioue* Oeometricte.' 

 Iloberval claimed the method M hb own, but hi* first publication* on 

 the subject followed those of Cavalerius. 



CAVALLI'NI, PIBTBO, a celebrated Roman painter of the 14th 

 _ ntury, and one of the earliest muter* of the modern Roman school, 

 WM born at Home in the latter half of the 13th century, and liv. .1 

 at Rome during the interval that the pope* resided at Avignon. 

 Yasari's account of Cav*llini i* somewhat inconsistent with the period 

 of hb death M adopted by Manni and Lanxi, 1344 ; for if, M Yasari 

 says, he WM eighty-five when he died, he must have been a much 

 older paintrr than Giotto, and can scarcely, M he states, have beeu 

 hi* pupil Vaaari indeed say* that Cavallini wu living in 1361, but 

 so many of his date* have been found to be incorrect, that he cannot 

 be strictly depended upon. Cavallini wu painter, architect, and 

 worker in mosaic. He assisted Qiotto in the mosaic or naviceUa of 

 the porch of St. Peter's ; and there are still some of his own mosaics 

 in the Barilica of San Paolo and at Santa Maria in Trastevere at 

 Rome. He executed also many paintings in the churches, but there 

 are no remains of them ; the last wore destroyed by the fire which, in 

 1824, almost entirely consumed the old Basilica of San Paolo: the 

 mosaics however, and a miracle-working wooden crucifix made by 

 Cavallini, remained uninjured. 



Cavallini painted also several frescoes at Florence, Orvieto, and at 

 Assui, some of which are still in a tolerable state of preservation. A 

 crucifixion in the church of Assisi is the most remarkable and the 

 best preserved. It contains a crowd of figures, some on horseback, 

 and dressed in a variety of costumes ; in the sky, which in a deep 

 bright blue, are several angels. It b a work of great labour, and 

 though the design is very angular, the figures sometimes distorted, 

 and the perspective incorrect, the figures have expression and character, 

 and if we consider the examples which can have been his only guides, 

 we must pronounce it a highly creditable and meritorious work. 

 Vertue believed that Cavallini designed the crosses which were 

 erected to Queen Eleanor, and that he waa the Petrus Romanus Civis 

 of the inscription on the shrine of Edward the Confessor in West- 

 minster Abbiey, and accordingly the architect of the shrine which 

 WM finished in 1270. Walpole adopts the supposition, and concludes 

 that Cavallini returned to England with the abbot Ware, who wu 

 elected in 1260, and went shortly afterwards to Rome to receive con- 

 secration from Urban IV. But this must be regarded aa a mero 

 conjecture. 



The celebrated miracle-performing picture of the ' Annunciation,' 

 or ' La Nunziata, 1 in the church de' Sci-vi at Florence, formerly attributed 

 to Cavallini, u now with more certainty attributed to a Maestro 

 Bartolomeo who lived at Florence in 1236. 



(Vasari, Vile de' PMori, <fec. ; Lanzi, Storia PUtorica, etc. ; Walpole, 

 Antedate i of Painting, <(>-.) 



CAVALLO, TIltKIUUS, a distinguished electrician, was born at 

 Naples in 1749, and in the university of that city ho completed his 

 education. In 1771 he wu sent to London, in order that he might 

 obtain a correct knowledge of the mode in which mercantile trans- 

 actions are conducted in England, but he soon abandoned the pursuits 

 of commerce for those of natural philosophy, and in these he con- 

 tinued to be engaged till hb doath, which took plsoe December 6, 

 1809. He wu buried in old St. Pancru churchyard, London. 



Cavallo wu less distinguished for originality of thought than for 

 hb vut industry in the research of the laws of nature by the way of 

 observation and experiment, and for his highly retentive memory; he 

 possessed thb faculty to such a degree that, at an age when he waa 

 unabb to comprehend the reasoning employed, he knew by heart all 

 the propositions and demonstrations in the books of Kuclid. He had 

 considerable akill in music, for which he retained the taste even after 

 hb sense of hearing wu considerably impaired. He wu appointed a 

 member of the Academy of Sciences of Naples in 1779, and in the 

 same year he WM elected a fellow of the Royal Society of London. 



The labours of Cavallo consisted chiefly in the performance of 

 experiments relating to electricity and magnetism, by which he con- 

 tributed much to the improvement of those branches of philosophy : 

 he alto made researches concerning the composition of the atmosphere 

 and the characters of minerals. In order to determine the nature of 

 the electricity in the atmosphere he employed what he called an 

 ' atmospherical collector : ' this was a long rod having at one extremity 

 a stnsll glui tube terminating with a cork from which were suspended 

 two pith ball*. The rod being held out u far M possible from an 

 upper window of the house, when the balls diverged by the electricity 

 of the atmosphere, they were drawn in, and the nature of the electric 

 fluid wu ascertained by examination. In 1776, whiln re.tiding near 

 Islington, he made a remarkable experiment with a kite, raised in the 

 air to the height allowed by 120 yards of string, from which lie 

 ascertained that a great quantity of electricity may exist in the 

 atmosphere without producing thunder or lightning. A small cloud 

 pasting over the house, he charged some jar* with the electricity 

 obtained from it, which he found to be positive ; by degrees tho 

 rjiiiutity diinitiMhod till it became insensible, but after a short timo 



