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again are broad ; as thofe for the breaft, belly, kc. Others 

 narrow ; as thofe for lips, fingers, &c. 



Guidon direfts the roller for the fhoulder to be fix fingers 

 broad ; that for the thigh, five ; for the leg, four ; for the 

 arm, three ; and the finger, one. See Bandage. 



ROLLFELD, in Geography, a town of Germany, on 

 the Maine ; 2 miles S. of Clingenberg. 



ROLLI, Paolo, in Biography, a Roman poet, bom in 

 1687, the fon of an architect. He was a difciple of the 

 celebrated Gravina, who infpired him with the love of poetry 

 and literature. The earl of Burlington having brought him 

 to England, which he commemorates in the dedication of 

 his opera of " Aftarte" to his noble patron, who attached 

 him to the court as mafter of the Tufcan language to the 

 princeffes. 



Rolli did not fpend an inactive life in England ; for, be- 

 fides being opera poet to the Royal Academy of Mufic till 

 it was broke up, teaching his language to the royal family, 

 and many of the firft nobility, he publifhed Italian odes, 

 fongs, elegies, endeca fillaba in the manner of Catullus, 

 which were much admired. Befides thefe he publifhed 

 epigrams, and fine editions in London of the Satires of 

 Ariofto, the complete works of Berni, Varchi, &c. 2 vols. 

 8vo. much efteemed ; the Decamerone of Boccaccio, the 

 Lucretius of Marchetti, Odes of Anacreon, and a tranfla- 

 tion of Milton's Paradife Loft, in Italian verfe, folio. 



Upon the death of queen Caroline, his royal prote&refs, 

 in 1737, he left England, and returned into Italy, where 

 he died in 1767, leaving behind him a very curious cabinet, 

 and a rich library of well-chofen books. 



ROLLIN, Charles, an eloquent writer and profeflbr, 

 was born at Paris in 166 1. He was intended for the fame 

 trade as that of his father, namely, a cutler ; but a Bene- 

 dictine, who had watched the opening of his mind, and 

 clearly perceived in him a genius for learning, procured for 

 him an exhibition at the college of Pleffis ; and he was im- 

 mediately taken under the protection of the principal, M. 

 Charles Gobinet. He went through, with much applaufe, 

 a courfe of claflics and philofophy ; and then ftudied theo- 

 logy for three years at the Sorbonne. A way feemed now 

 open to him in the college of Pleffis, and in 1683 Rollin en- 

 tered that feat of learning. In 1687 he was made profeffor 

 of rhetoric, and in 1688 he obtained the chair of eloquence 

 in the Royal College. He became rector in 1694, and oc- 

 cupied that poll two years. During his adminiftration, he 

 revived the fiudy of the Greek, fubilituted academical ex- 

 ercifes for the reprefentation of tragedies, and introduced 

 the cuftom of obliging the fcholars to get the holy fcriptures 

 by heart. In 1698 he was appointed coadjutor of the col- 

 lege of Beauvais, an office which he held till 1712. In the 

 year 1720 he was again rector of the univerfity ; after which 

 he entirely devoted himfelf to the compofition of the works 

 for which his name is particularly celebrated, and of which 

 the following is an enumeration of the principal : " Traite 

 de la Maniere d'enfeigner et d'trtudier les Bcltes Lettres par 

 Rapport, a l'Efprit et au Coeur," 4 vols. i2mo., pub- 

 Hfhed at different times between the years 1726-8, with a 

 fupplement relative to the ftudies of children, and the edu- 

 cation of females. Several editions of this work have been 

 publifhed. " L'Hiftoire Ancienne des Egyptiens, des 

 Carthaginois, des Aliyriens, des Babyloniens," &c. 13 vols. 

 I2mo., publifhed between 1730-38. Voltaire fpeaks in 

 terms of high refpect of this work : while he admits that 

 the latter volumes are not written with fo much care as the 

 earlier ones, yet he fays it is the beft hiftorical compilation 

 in any language ; becaufe the compilers of fuch works are 

 feldom eloquent, which Rollin always was. It has been 



thought, and with probability, that Rollin wrote hiflory 

 chiefly for the opportunity of throwing into the narrative 

 abundance of ufeful reflections. He paid too much credit 

 to the exaggerations of the ancient hiftorians, and is in a 

 good meafure void of that critical fagacity, which fhould 

 be characteriftic of the writer of hiilory. This quality 

 could fcarcely be expected from the man who gave implicit 

 creed to the miracles, as they were called, of the abbe de 

 Paris, and who was accuftomed to pray kneeling before his 

 tomb. The other principal work of Rollin was " Hiftoire 

 Romaine depuis la Fondation de Rome jufqua la Bataille 

 d'Actium," 8 vols. l2mo. This was continued by Crevier 

 to the reign of Conftantine. Rollin died with a character 

 univerfally eileemed, at the age of 80, in the year 1741. 

 His writings have been popular both in France and in 

 other countries. Voltaire fays, that he was the firft mem- 

 ber of the univerfity who wrote with purity and dignity. 

 He began with ellablifhing his reputation as a claffical 

 fcholar, by a number of Latin harangues and poems, which 

 have been printed ; and by an edition of Quinctilian, in- 

 tended for the ufe of fchools, which he illuftrated with fhort 

 notes, and a preface. This edition of Quinctilian has been 

 feveral times reprinted, in 2 vols. l2mo. ; that in our pof- 

 fefiion was publifhed at Paris in 1774. 



ROLLING, Rotation', in Mechanics, a kind of cir- 

 cular motion, in which the moveable turns round its own 

 axis, or centre, and continually applies new parts of its fur- 

 face to the body it moves upon. 



Such is that of a wheel, a fphere, or the like. Such, 

 particularly, are the motions of the earth, the planets, &c. 



The' motion of rolling is oppofed to that oijliding ; in 

 which the fame furface is continually applied to the plane it 

 moves along. 



It mull be noted, that in a wheel it is only the circum- 

 ference that properly rolls ; the reft proceeds in a compound 

 angular kind of motion, and partly rolls, partly Hides. The 

 not diftinguifhing between which two, occafioned the diffi- 

 culty of that celebrated problem, the rota Arijlotelica, Arif- 

 totle's wheel. 



The friction of a body in rolling, or the refiftance made 

 to it by the roughnefs of the plane it moves on, is found 

 to be much lefs than the friction in Aiding. 



Hence, the great ufe of wheels, rolls, &c. in machines ; 

 as much of the aftion as poffible being laid thereon, to make 

 the refiftance the leffer. 



For the laws of bodies rolling on inclined planes, fee In- 

 clined Plane and Descent. See alfo Rotation. 



Rolling, in Gardening, the work of rendering any fur- 

 face level by means of the roller. It is practifed equally 

 for the purpofe of bringing the furfaces of the gravel and 

 other kinds of hard walks and roads into an exact and even 

 order, as well as thofe of pleafure-grounds, which are in the 

 condition of fhort or mown grafs. And it is Cometimes ap- 

 plicable in other intentions, as thofe of rolling in particular 

 forts of feeds, inftead of putting them in by means of 

 treading the beds by the feet, and the rolling down and 

 rendering more clofe the too loofe and open grounds of 

 gardens, &c. 



The rolling down of garden-walks and roads fhould al- 

 ways be done, when poffible, immediately after flight falls 

 of rain, the gravel or other kinds of materials being pre- 

 viously put in fuitable order by fweeping and raking with 

 proper rakes for the purpofe. The roller is then to be 

 carefully drawn up on one fide and down the other of them 

 as clofe as poffible to the grafs verges, and afterwards along 

 the middle parts, in a forward and backward direction, which 

 moftly completes the work. 



In 



