SOL 



were ufed, during the chief part of the iaft century, by all 

 finging-mafters unable to write to the wants and abilities of 

 their fcholars. But the pafTages in thefe, though excellent 

 in their day, being now worn out and comnnon, are gene- 

 rally fuperfeded by the folfeggii of Aprile. 



SOLFERINA, in Geography, a town of Italy, in the 

 duchy of Mantua ; 17 miles N.W. of Mantua. 



SOLFWITZBURG, Solvesborg, or Syhi/borg, a fea- 

 port town of Sweden, in the province of Blckingen. This 

 town, formerly more flourifliing than it is at prefent, is 

 almoft lurroundedby the Baltic fea. It has a harbour, and 

 a caftle in a ruined itate. It is faid to be the place where 

 the Lombards aflembled when they left their country, and 

 migrated in fearch of new habitations; 35 miles W.S.W. 

 of Carlfcrona. N.lat. 56° 9'. E. long. 14° 26'. 



SOLI, or AJhaja Tujla, a town of Bofnia ; 20 miles 

 W. N.W. of Zwornick. 



Soli, or Jokari Tujla, a town of Bofnia ; 16 miles 

 W.N.W. of Zwornick. 



SOLIANOl, a fortrefs of Ruflia, in the government 

 of Kolivan, on the Irtifch. N. lat. j4° 20'. E. long. 

 75° 14' — Alfo, a town of Ruflia, in the government of 

 Irkutfl< ; 20 miles N.N.W. of Selenginfl<. 



SOLIANSKOI Stanitz, a town of Ruflia, in the 

 government of Irkutfk, os the Lena; 16 miles N.E. of 

 Olekniinflc. 



SOLICITATION of Gravity. See Paracentric. 



SOLICITOR, or SOLLICITOR, SoUcitator, a perfon 

 employed to follow, and take care of, other perfons' fuits 

 depending in courts of law or equity ; formerly allowed 

 only to nobility, vvhofe menial fervants they were ; but now 

 regularly admitted to pradife in the court of chancery. See 

 Attorney. 



The king has a folicitor-general, who holds his oflice by 

 patent, during the king's pleafure. The attorney -general 

 and he had anciently a right to their writs of ium'mons, to 

 fit in the lords houfe on fpecial occalions, till the 13 Car. II. 

 fince which time, they have almoft conftantly been chofen 

 members of the houfe of commons. 



The folicitor-general has the care and concern of ma- 

 naging the king's affairs, and hath fees for pleading, befides 

 other fees arifing by patents, &c. He hath his attendance 

 on the privy-council ; and the attorney-general and he were 

 anciently reckoned among the officers of the exchequer : 

 they have audience, and come within the bar in all other 

 courts. 



To the queen's houfehold there belongs alfo an officer 

 with this appellation. See Pkeci:dence." 



SOLID, in Phyfus, a body wliofe minute parts are con- 

 nefted together, fo as not to give way or flip from each 

 other, upon the fmalleft impreffion. 



The word is ufed in this fenfe, in contradiftinclion to 

 jlmd. 



Solid Bodies, Atmofphere of. See Atmosphere. 



For tlie laws of gravitation of fohds, immerged in fluid- 

 fpecifically, either lighter or heavier than the folids, fee 

 Gravity and Fluid. 



To find the fpecific gravity of folids, and its ratio to that 

 of fluids, fee Specific Gravity. 



For the laws of the refillance of folids moving in fluids, 

 fee Resistance. 



Solid, in Geometry, is a magnitude endued with three 

 dimenfions, or extended in length, breadth, and depth. 

 Hence, as all bodies have thefe 'three dimenfions, and no- 

 thing but bodies, folid and body are frequently ufed in- 

 difcriminately. 



A folid is terminated, or contained, under one or more 



SOL 



planes or furfaces, as a furface is under one or more line*. 

 From the circumllances of the terminating lines, folids be- 

 come divided into regular and irregular. 



Solids, Regular, are thofe terminated by regular and 

 equal planes. 



Under thisclafs come the tetraedron, hexaedron or cube, 

 oftaedron, dodecaedron, and icolaedron. See Tetrak- 

 DRON, Cube, &c.; and for the meafure of thefe bodies, 

 fee Mexsi/ration. 



Solids, Irregular, are all fuch at do not come under the 

 definition of regular ones. Such are the fphere, cylinder, 

 cone, parallelogram, prifm, pyramid, parallelepiped, &c. 



For the ratio of geometrical folids, all pnfms, parallelepi- 

 peds, cylinders, pyramids, and cones, are in a compound 

 ratio of their bafes and altitudes ; fo that if the bafes be 

 equal, they are in the fimple ratio of the altitudes ; or, if 

 the altitudes be equal, tliey are as their bafos : and as the 

 bafes of cylinders and cones are circle*, and circles are in 

 the duplicate ratio of their diameters, it follows that all 

 cones and cylinders are in a ratio compounded of the diredl 

 ratio of their altitudes, and the duplicate ratio of their 

 diameters. 



The genefes, properties, ratios, conftruftions, dimenfions, 

 &c. of the feveral folids, regular and irregular, fpherical, 

 elliptical, conical, &c. fee under each refpeftire article. See 

 alfo Me.nsuration. 



Solid, Meafure of a. See Measure. 



Solid, Cubature or Cubing of a. See Cubature and 

 Solidity. 



Solids, To find the Surfaces of. See Area, Sui'ERFIcies, 

 and Mensuration. 



Solid of the leajl Refjlance. See Resistance and Iso- 

 perimetry. 



Solid Angle, is that formed by three or more plain an- 

 gles meeting in a point. (See Angle.) Or, more itriftly, 

 a folid angle, as B (Pto XIV. Geometry, Jig. i.), is the 

 inclination of more than two lines, A B, B C, B F, which 

 concur in the fame point B, and are in the fame planes. 



Hence, for folid angles to be equal, it is neceilary they 

 be contained under an equal number of equal planes, dif- 

 pofed in the fame manner. 



And as folid angles are only dillinguifliable by the planes 

 under which they are contained, and as planes thus equal 

 are only diftinguifliable by comprefence, they are fimilar ; 

 and confequently fimilar folid angles are equal, and vice 

 verfd. 



The fum of all the plane angles conftituting a folid angle, 

 is always lefs than 360' ; otherwife they would conllitute 

 the plane of a circle, and not a folid. 



The theory of folid angles is, perhaps, rather a fubjeft of 

 curiofity than utility ; yet as it has given rife to much dif- 

 cuffion amongft mathematicians, it may not be amils to be- 

 llow a few lines in explanation of what we coiifider to be 

 the moft fcientific method of confidering this fubjetl. 



Euclid defines a folid angle to be that which is made by 

 the meeting of more than two plane angles, which are not 

 in the fame plane, in one point ; but a more general defini- 

 tion is, that " a folid angle is the angular fpace included be- 

 tween feveral plane furfaces, or one or more curve furfaces, 

 meeting in the point which forms the fummit of the angle." 



According to this definition, fohd angles bear juft the 

 fame relation to the furfaces which comprife them, as plane 

 angles do to the lines by which they are included ; fo th.it, 

 as in the latter, it is not the magnitude of the lines, but their 

 mutual inclination, which determines the angle ; ju(t fo, in 

 the former, it is not the magnitude of the planes, but their 

 mutual inclinations which determines the angles. And 



henc. 



