Of 0XF0%T>~SH1XE- %9 J 



the paper dance and play as before, and that in all parts of B(j 

 alike ' but if you ftrike it on the middle 2, the paper will not ftir. 

 The reafon whereof feems to be, that Ci. 2D being Vnifons to 

 BC,per Princip. 2. if either be touched, BC will anfwer it, per 

 Prop. 1. But CD having a difproportionate/e/zgM, bignefsnnd. ten- 

 fion to BC : if Touched in 2 (whereby the whole firing is equally 

 moved) it cannot affeft it, by reafon of their different vibrations ; 

 as in the former Proportion, . E. D. 



Note that this, and (efpecially) the following Experiments, 

 muft be tryed curioufly by a gentle touch of the siring (only fo 

 hard as to make the papers move ) and that with a bow rather than 

 the finger : For if CD be touched boldly in 2 (with the finger he 

 means, not the bow J by reafon of the ftrong motion communica- 

 ted to its parts (and happily divided there,which perhaps may be 

 the caufe too, why,ifyoU ftrike it with the bow in 2, it fends forth 

 forth a fcreaking broken found) BC will tremble, but with a mo- 

 tion nothing fo brisk, as when touched with but half the force any 

 where elfe. 



Prop. 4. If thelejfer of two Fifths, CD Fig. 8. be touched on 

 either of its halves C2. 2D, each third part of the greater D 

 X, XZ,ZE, will anfwer it, but if in the middle 2 they will 

 not ftir. Which will plainly appear, 



By laying papers as before, on /, x, 3, ^, v, if then you ftrike CD 

 on C2 or 2D, you'l fee the papers on /, 3, v, frisk and daunce, 

 while thofe on x and^ftand ftill, but if you ftrike it on 2 none 

 will move. Demonslratio eadem eft cuntfuperioribws, for Ci . 2D are 

 Vnifons, and CD an clave, to DX, JfZ, ZE,per Prim. 2. 



If it be demanded, wherefore DZ or Jl ('which are Vnifons 

 to CD per Princip.2.) do not vibrate when it is touched in 2. He 

 anfwers, if DZ, then by the fame reafon XE alfo,and fo XZ would 

 at the fame time be moved by contrary motions, as in Fig. 16. 

 Q^E.A. 



Prop. 5. If the greater of two fifths DE be touched, Fig. 8. on 

 either of its thirds DX, XZ, ZE, each half of the leffer Ci. 

 2D, will anfwer it : but if in the divifions XZ,they will not ftir. 



Experimentum & demonftratio inftituuntur utfupra, DX^ XZ, ZE, be- 

 ing Vnifons to C2. 2D, and oclaves to CD, per Princip. 2. 



Pp If 



