.9648 

 •947 Q 

 •9433 



•9423 

 .9419 

 .9368 

 •9342 



•9235 

 .9232 

 .9263 



■9233 



.897 



G R A 



T^'as, yellow .... 



Lard 



Spermaceti .... 



Butter ..... 



Tallow ..... 



Fat of hogs .... 



of veal .... 



of mutton .... 

 of beef .... 



Ambergr^'afe .... 



Lamp oil - 

 Solution of pure ammonia 



Gravitv, in Mechanics, denotes the conatus or tendency 

 of bodies towards the centre of the earth. 



Thst part of mechanics which coniidi-rs tlie motion of 

 bodies ariiing from gravity, is peculiarly callcd_y7ir/;Vj. 



Gravity, in this view, is dilHnguifhcd into ahfohite, and 

 relative. 



The former is that with which a body defcends freely 

 through an unrefifting medium : the laws of which fee 

 und;r Df.>;cent of lodks, Acceleuatiox, Motion, In- 

 el'med Plane, Sfc. 



The latter is that with which a body defcends after having 

 fpent part of its weight in overcoming fome refdlance. 

 Snch is that with which a body defcends along an inclined 

 plane, where fome part is employed in overcoming the re- 

 liflauce, or fridion of the plane. The laws of relative gra- 

 vity, fee under i/iclineJ Plane, Descent, Fluid, Resist- 

 ance, Szc. 



Gkavity, Cen.'re of. 5:e Cestf.r of grjvily. 



Gravity, D'lam.ter of Sec Diametek 15/' n^ri7'y;V_y. 



GllAi'iTY, Paracentric foUcitation of See Pauacentric. 

 ■ Gravity, Plane of See Flase of gravi/y. 



Gravity, Retardation from. See Retardation'. 



Gravity of the air. Sec Weight of the Jir, Am and 

 Atmosphere. 



Gravity, in Mu/ic, is an affedion of found by which it 

 becomes denominated ^jriii'i", low, or flat. 



Gravity ftands in oppolition to acutcnefs, wliich is that af- 

 fection of found by which it is denominated acute, fliarp, or 



The relation of gravity and acutcnefs, is the principal 

 property on which mufic depends ; and it is the dillintt, 

 fixed, and determinate quality of this relation which entitles 

 found to the denomination of melodious, harmonieaU or mufical. 



Gravitv is, therefore, that modification of found by which 

 it is confidered as grave or low, with refpeft to, or compared 

 with, other founds, that are acute or high. See Acute. 



The degrees of gravity, &c. depend on the nature of the 

 fonorons body itfelf, and the particular figure and quantity 

 thereof: though, in fome cafes, they likewife depend on 

 the part of the body where it is ftruck. Thus, e. gr. the 

 founds of two bells of different metals, and the fame (hape 

 and dimenfions, being tlruck in the fame ])lace, will differ 

 as to acutenefs and gravity; and two bells of the fame metal 

 will differ in acutenefs, if they differ in (liape or magnitude, 

 or be ilruck in different part?. 



So in chords, all other things being equal, if they differ 

 either in matter, or dimenlion, or tenfion, they will alfo 

 dilTer in gravity. 



Thus again, the found of a piece of gold is much graver 

 than that of a piece of iilver of the fame fliapc and dimen- 

 tions; and in this cafe tte tones arc, c<eteris paribus, Jiro- 

 portional to the fpecific gravities: fo a fohd fphere of 

 brafs, two feet in diameter, will found graver than another 

 of one foot diameter; and here the tones are proportional 

 10 the quantities of matter, or the abfolute weights. 



Vol. XVI. 



G R A 



But it muft be obfervcd, that acutenefs and gran'tV, as 

 alfo loudntfs and lowncfs, are but relative thinTs ' Wc 

 commonly call a found acute and loud, in refp«ft to^anorhfr 

 which M grave, or low with refpeA to the fonnerj fo tliat 

 the fame found may be both grave and acute, and alfo loud 

 and low, in different comparifons. 



The degrees of acutenefs and gravity makrf the different 

 tones or tunc;, of voice, or found ; fo we fay one found 

 IS in tune with another, when they arc in the fame degree of 

 gravity. 



The immediate caufe or means of this diverfity of tone* 

 lies very deep. Mathematicians exprcfs the ^oportion of , 

 found to found, by the ratio of numbers. The modem.? f»x 

 it on the different velocity of the vibrations of the fonoroui 

 body: in \yhich fenfc gravity may be defired, a relative pro- 

 perty of found, which, with refped to fome other, i., th'- 

 effecl of a kifer number of vibrations aocompliflied ir. th- 

 fame time, or of vibrations of a longer duration. In which 

 feni'e alfo, acutenefs is the effect of a greater number of vi- 

 brations, or vibrations of a (hortcr duration. 



If the vibrations be ifochronous, the found is called nm- 

 fical, and is faid to continue at the fame pitch. See Ckohd 

 and Stuing, in flTufic. 



If two or moie founds be compared in tlie relation of 

 gravity. Sec. tliey are either equal, or uneqval, in the degree 

 of tune. Such as are equal, or produced by ifochronoui vi- 

 brations, arc called unifons. 



The unequal including, as it were, a diftancc between each 

 other, coniHtute that we call an interval in mufic ; whicJi 

 is properly the difference, in point of gravity, between two 

 founds. 



Upon this inequality, or difference, does the whole effeft 

 depend ; and in refpeA of this it is, that thefe intervals aro 

 divided into concords and difcords. See Har.monics ard 

 Ratio. 



As the gravity of founds depends on the thicknefs, length, 

 and tenfion, of the firings, or on the length and diameter of 

 the pipes, and, in general, on the volume or mafs of the fo- 

 norous bodies ; the increafe of any of thefe qualities (except 

 tcnlion) augments the gravity of found. But there is no 

 abfolute point of gravity in nature, and no found is^<rw or 

 acute, but by co:nparifon. 



GRAULKET, in Geography, a town of France, in the 

 department of the Tarn, and ciiief place of a canton, in the 

 dillria of Lavaur ; nine miles N. E. of Lavaur. The place 

 contains 3419, and the canton 7159 inhaoitants, on a terri. 

 tory of 135 kilionietres, in (w communes. 



GRAUN, Charles Henry, in Biography, chapel- 

 mailer to Frederic II. the late king of PruHia", was the 

 favourite compofer of that prince, from 1732 to tlie lime of 

 his deceafe, in 1759. On the accelTion of the prince of 

 Pruffia to the throne in 1 740, his majelly, havin)^ determined 

 to have an Italian lyric theatre in his capital, fent Graun fo 

 Italy to fhidy the Italian language and tafte in mufic, and 

 to engage vocal performers. Graim rcinaincd t«o years in 

 Italy, during which time the king, his royal mailer, had con- 

 llructed, in Ipite of the Silefian war, one of the iroll mapfni- 

 fioent, complete, and convenient theatres in Europe, far 

 which Graun was the compofer to the end of hi? life ; and 

 even after his doceaie little mulic but of iiis compolition 

 was ever performed in it for a long time. 



Tlie works of this mailer are very nuinerous ; before his 

 arrival at lierlin, lie let three or four operas in the German 

 language at Brunlwick, but the words were bad, and it is 

 not fair to judge of his genius by thofe early produftions. 



He compoled for the Berhn theatre, in the fpace of four- 



tseu years, from 1743 to I7j6, twcnty-fcvcn Italian opcra.<! 



4 •'5 ¥«d 



