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fig. 5. conftriiifted by the late Rev. W. Jones;. The firings, 

 iufti.-ad of being on theoiitfide, are fixed to a founding -board 

 or belly withia a wooden cafe, and ihe wind is admitted to 

 the-n through an horizontal aperture. In this fonn the in- 

 llruni -nit is portable, and mav be ufed any where in the open air. 



bolus's harp produces all vht harmonics of a fuigle itring, 

 divided in liarmonical proportion. See Harmomcs. The 

 tenilon of the llrings muil not be great ; as the air, if gentle, 

 has not iufficicnt power to make them vibrate ; and, if it 

 blows fvofli, the indruniL-nt does not fing, but fcrcam. Its 

 crefcendo and diminuendo, or the gradual advancing and 

 retiring of its dchcate tones, can onlv be defcribed by the 

 jnilrument itfelf. 



, Kircher has attempted to account for the plienomena of 

 the yEolian harp, b;. fuppoling the current of air to ftrike on 

 different portions of the llring. i3ut this is contraiy to ex- 

 perience ; for, if We fuppofe tlie ^olian note to be one-lifth 

 above the original note of the ilring, that is, one third of the 

 whole, then, acctn-ding to Kircher, the remaining part would 

 be at rell, which is not the faft ; for an obftacle applied to 

 any other point belides the quiefccnt points of divifion, will 

 deitroy the iEolian tone. The chords alfo that would arife 

 o:i this theory are not fuch as really take place in nature ; 

 thus, where the chord confifts of the notes F and A, the 

 firft note F is produced, according to Kircher, by the blafts 

 ilriking on one fourth of the ftring : and in this cafe, the 

 remLiining part ot the llring muil be at rell according to 

 Kircher, which is coatrar)' to experience ; or, if it be agi- 

 tated as one ilring, it muil produce the note of three-fourths 

 of the whole ftring, that is, a fourth above the bafs note ; 

 ■whereas, the note really produced is the double oftave to 

 the third above the bafs note. 



Ivir. Young, in order to afcertain the order of the notes 

 in this inftrument, took off all the ilrings hut one ; and, 

 placing it in a" proper fituation, he was furpriied to hear a 

 gretit variety of notes, and frequently fuch as were not pro- 

 duced by any aliquot part of the ftring ; and he often heard 

 a chord of two or three notes from this fmgle ftring. Thefe 

 complex and extraordinary phenomena at firft* perplexed 

 Iiim ; and he almoft defpaired of being able to account for 

 them on the principle of aliquot parts. On farther ex- 

 amination, however, he found that they all flowed naturally 

 and eafily from this principle. Having direfled his atten- 

 tion to the effeft of a current of air rulhing againft a 

 ftretched elaftic ftring, he obferved, that a blail agamft the 

 middle point of the Ilring moved the whole of it from its 

 reclilincal pofition ; and that the ftring by its elafticity, re- 

 turned to its former pofition : fo as thus to continue vibrat- 

 ing and exciting pulfes in the air, which produced the tone 

 of the entire ftring. If the current of air be too ftrong and 

 rapid, when the ftring is bent, it will retain its curvature. 

 But though the whole ftring cannot perform its vibrations 

 in this cafe, the fubordinate aliquot parts may ; and thefe 

 will be of different lengths according to the rapidity of the 

 blaft. Thus, when the velocity of the current increafes fo 

 as to prevent the vibration of the whole ftring, thofe particles 

 which llrike againft the middle points of the halves of the 

 ftring agitate thofe halves, as in the cafe of fympathetic and 

 fecondary tones ; and as thefe halves vibrate in half the 

 time of the whole ilring, though the blail may be too rapid 

 to admit of the vibration of the whole, yet it can have no 

 more eff"etl in preventing the motion of the halves than it 

 would have on the wliole ftring if its teniion were quad- 

 ruple : for the times of vibrations in ftrings of different 

 lengths, and agreeing in other circumllances, are direclly 

 as the lengths; and in ilrings differing in tenfion, and agree- 

 ing in other circumftajices, invcrfely as the fquare roots of 



the tcnfior.s : and therefore, their yibrttions may become 

 ftrong enough to excite fuch pulfes as will affeifl the drum of 

 the ear : and the lame may be faid of other aliquot divifions 

 of the ftring. Thofe particles which ftrike againft fuch 

 points of the ftring as arc not in the n:iddle of aliquot parts, 

 will interrupt and counteraft each other's vibrations, as in 

 the cafe of fympathetic and fecondary tones, and therefore 

 will not produce a fenfible eli'efl. Thefe principles are 

 illullrated and applied by Mr. Young in his " Enqulrv 

 into the Principal Plienomena of Sound and Muiicul 

 Strings," printed at London in 17H4, 8vd. 



iEON, AWN, ag(, literally fignifies the duration of a 

 thing. But the word has been ufed by Greek writers in 

 different fenfes. It was firft applied to the age of man, or 

 "the duration of human life. In fucceeding times it was 

 tifed by philofophcrs to exprefs the duration of fpiritual and 

 invlfible beings. 



Xf-ovo; was ufed to denote the meafure of corporeal and 

 changing objeCls ; and khv or xon, for the meafure of fuch 

 as were immutable and eternal. And, as Ood is the chief 

 of fpiritual and immutable beings, his eternal duration was 

 expreffed by this term, and tluis it is now commonly imder- 

 ftood. It was afterwards attributed to other fp-ritual and 

 invifible beings ; and the oriental philofophers, who lived 

 about the time of Chrill's appearance, and made nfe of 

 the Greek language, underilood by it the duration of eter- 

 nal and immutable things, the fpace or period of time in 

 which they exltl. By a metonymy, the term was en>ployed 

 to fignify the beings themfelves. Thus, the Supreme Being 

 was called aiav, or ^on ; and the angels alfo dillinguilhed 

 by the title of i'Eons. Accordingly, the Gnoftics, who had 

 formed the notion of an invifible and fpiritual world, com- 

 pofed of entities or virtues, proceeding from the Supreme 

 Being, and fucceeding each other at certain intervals of 

 time, fo as to conftitute an eternal chain, of which our 

 world was the terminating link, afligned to the beings that 

 formed this chain a certain term of duration, and a certain 

 fphere of adlion. Thefe terms of duration were at firft 

 called aiw«i, Sons, and they themfelves were afterwards 

 metonymically diilinguilhed by that title. Moflieim's Eccl. 

 Hift. by Machine, vol. i. p. 89. 8vo. 



Some have affixed another idea to the word ann ; in order 

 to which they have made ufe of the pliilofophy of Plato, 

 giving reality to the ideas which that philoi'opher had 

 imagined in God ; and even perfonifying them, and feign- 

 ing them diftinet from God, and to have been produced by 

 him ; fome male, others female. See Platonism. 



Thefe ideas they call leons ; of an aifemblage of which 

 they compofe their deity, calling it "scXr.fi-tMi., a Greek word, 

 fignifying fulnifs. 



Some fay that Simon Magus was the firft inventor of thefe 

 Kons, which feem, however, to have fprung from the ori- 

 ental philofuphy, and which were adopted by the Gnoftics ; 

 aftenvards brought to perfedlion by Valentinus ; who, re- 

 fining on thofe who preceded him in this way, produced a 

 long genealogy of sons, to the number of 30. The firft, 

 and moft perfeft, he particularly denominates rij-oiv, Proon, 

 that is, pn-ex'ijlent ; bcfide other names, the moft ufual 

 whereof was that of Bythos, KuSo;-, depth. 



This Bythos, he fays, continued long alpne with Evkux^ 

 Ennan, Thought ; whom Valentinus alfo called \xfic, Grace^ 

 and Siy:i, Silence. At length Bythos, with Sige, produced 

 Nous, Nk.;, Underjland'wg ; and AXt^nx, Truth, her filler. 

 Nous begat two asons ; Logos, S.tyv, Word ; and Zoe, Zati, 

 Life ; which begat two others ; Anlhropos, AnSpun-o-;, Man ; 

 and Ex-tXncriz, Church. And thefe eight sons were the 

 chitf of all. the reft. 



The 



