31* Xxpertments and Theary »f the Harp of Eolui. 



tr Malcolm) '. and, therefore, their vibrations may become ftrong enough to excite fuch 

 pulfes as will afFe£l the drum of the ear: and the like may be faid of other aliquot divifions 

 of the ftring. In the fame manner as (landing corn is bent by a blaft of wind, and if the 

 wind be fufHciently rapid it will have repeated its blaft before the ftem of corn can recover 

 its perpendicular pofition, and therefore will keep it bent : but if it decays in rapidity or 

 Hrength, the ftem of corn will have time to perform a vibration before it is again impelled j 

 iand thus it will appear to wave backwards and forwards by the impulfe of the wind. Thofe 

 particles which ftrike againft fuch points of the ftring as are not in the middle of aliquot 

 part?, will interrupt and counteraft each other's vibrations, as in the cafe of fympathetic and 

 fecondary tones, and therefore will not produce a fenfible efFefl. That we may be more 

 fully perfuaded of the truth of thefe principles, I fhall here fet down the order of the Eolian 

 notes as accurately as a good ear could difcover. 



Ohjervat'wn I. The original note of the ftring being the grave fifteenth to low F on the 

 violin, the Eolian notes as given in the annexed page * were diftindl^ly perceived, and nearly 

 in the fame order in which they are fet down. 



From the table of proportions in Smith's Harmonics, p. lo, we may fee that thefe notes 

 ■were produced by fuch aliquot parts of the ftring as are denoted by the fradlional indexes, 

 which are written over them agreeable to the theory laid down. 



Obfervat'wn II. While feme of thefe notes were founding I applied anobftade indiflFerently 

 to any point, which divided the ftring into fuch aliquot parts as would produce thefe notes,, 

 and the Eolian note was not interrupted: but if I placed it in any other part, the tone was in- 

 ftantly extinguiflied. This evidently ftiews that the entire ftring is, in faft, refolved into fuch 

 parts, as, from the preceding chain of reafoning, we fliould have been induced to prefcribe 

 for it. 



Obfervat'wn III. I applied an obftacle flightly againft the ftring, fb as that its diftance from 

 the extremity (hould be an aliquot part of the whole ; and the Eolian note was that which 

 would be produced by fuch an aliquot part j thus we may in general predetermine what note 

 the harp fhall found. But this efFe(St will not invariably take place; becaufe, though the 



♦ The engraved table of notes confifts of three fets of lines, wkh the cliff G on the fecond h'ne from the 

 bottom, as ufual. In thefe the notes are written, and above each note the fraftion which exprefles the di- 

 vifion of the ftring. As all thefe fraftions have i for their numerator. I fcall here give the letters exprelfing 

 the notes, and the denominator or number denoting the fubdivifion :— "Middle C 6 ; — lower F 4; — mid. A 5 } 

 — upper E, flat, 7, nearly ; — mid. C 6 ; — mid. A 5 ; — up. D 7, nearly j — up. F 8 ; — up. D 7, nearly ; — 

 mid. C 6 ;— mid. A 5 ;— up. D 7, nearly , — up. F i ; — up. F 8, with up. i> 7, nearly ;— mid. C 6 : — up. D 7, 

 nearly j— up. E,flat, 7, nearly;— up. E 7,nearly ;— up. F 8 ;— up. A 10 ;— up. G 9 ;— up.F 8 ;— mid. C 6, with 

 «p. E, flat, 7, nearly ; — mid. C 6 ;— low F 4, with mid. A 5 ;— mid. A 5 ;— up. E^flat, 7, neirly ;— mid; A 5 j 

 —up. E, flat, 7, nearly ; — mid. C 6;— up. F 3;— up. G 9;--up. F 8;— up. E Aiding to up. E, flat,. 7, nearly, 

 »d to up. D ;— mid. C 6 ;— up. F 8 ;— up. E, flat, 7, with mid. C 6 ;— mid. C 6 ;— up. E,, flit, 7, nearly ;— 

 Wid. A %, with mid. C 6, and up. E, flat, 7, nearly ;— up, E, flat, 7. with up. F 8;— up. F 8 ;— up. B 1 1> 

 aearly;— up. Aioj— up. F 8, with up. G 9;— up. E flat, Aiding toup. D;— up. C 6;-- up. D. 7, with 

 »p F 8, &c. &c. 



obfiaclft 



