dctx'-\- d dy' -\- d d z* — d d s' zn a a.d s*; 

 flcquc radiiis ofculi crit 



a' 



§. 31. His prncnotatis , fi Q cxprimat cl.-inicitatem 

 abfoliuam tili in fingulis punclis, quam hic t.uiquam con- 

 ftantem afrumemiis , it:i vt filum vbique vniformiter cras- 

 lum fit concipiendum j tum acquationcs pro aequilibrio 

 erunt 



l- /dy/P ds^/dx/qdszzGr. 

 II. /dz/Qds^/dy/R ds~Gp. 

 II[. /dx/Kds~/dz/? ds — Gq, 

 quae differcntiatac praebent 



dy/?ds-dx/(lds=Gdr, 



dz/Q^ds-dj/RdszzGdp, 

 d x/R ds-dz/V ds — Gdq. 



§. 32. Hinc primo tam /Q^ds quam /R d s per 

 fPds cxprimamus eritque 



/Qds-I^JFds^^-ll. ct/Rdsz=:^^J?ds-^9^\ 



qui valores in formula pro tenfione T data fublhtuti 

 praebent hanc exprtirioncm : 



Tzz~f-^/?ds~A^/Pds~JL^--fPds~^.tL^y-~9A±^^ 

 qu3c reducitur ad hanc formam: 



T = -^r?ds-{- ^ci-dy -ajd^ 



ax J ' d X U $ » 



vndc coiligimus: 



fP ci ^ — G (dr dy — d g^iz) _ 7 d x 



Simiiique modo reperietur; 



/Q 



