^m ) 157 ( ^!^« 



{aapp-\-bb-\-kk-\~iabp cOf. isi) v v ^ff^ 

 quae, pofito porro bb-i-kk — bc^ fit fimplicior, fcil. 



vv[aapp-{-bc~\~2abp cof. (Si) —ffy 



vbi notafle iuuabit , fi corpus ex ipfo pundo B fufpende- 

 retur, diftantiam centri ofcillationis ab hoc pundo futu- 

 ram effe zz: b -\- ^ — c. Praeterea vero faciamus 



licof. Q — 2, ct aequatio noftra induet hauc formam: 



i}v{aapp-\-bc-\^zapz)~ffy 

 quae per logarithmos dat 



&lv-hl{aapp-\-bc-\-2apz) — z If, 



vnde differentiando fit 



d V — a a p d p — a (p d z -^ z d p)' 



<o — aofp-+-i>c-+-»apa 



^. 17. Simili modo etiam in altera aequatione 

 differentiali , pofito u~vp et b cof u — s , vt fiat b d {H 

 fin. &; ~ — dz, habcbimus, 



a{p dv -\~v dp) -\- 2 dv -\- ^^ — 6 , 



quae per v diuifa praebet 



iv — __ a d p d z 



V ap-+-x (i — p) {a p -+- z)* 



Hic iam loco ^ fubftituatur valor ante inuentus, orietHr"^ 

 quc fequens aequatio inter binas variabiles p tt Z'. 



< d p _ I d_K aa p d 1» -^:_°- CP d z-t- z d p) 



c p-h z ' (i — p) 1« P -+- 2) — aapp-i-bc-f- z a p » * 



quae fublatis fradtionibus reducitur ad hanc : 

 #(1 — /) {bc-zz)dp-\-{bc-{-a ap' -\-apz{i -\-p) ) dz-O^ 



V a §• '»• 



