MOTVS FLVIDORV M 283 



horumque pundtorum ternas coordinatas axibus paralle- 

 las conftituamus , eiunt translationes momentaneae fe- 

 cundum hos axes : 

 AV-AL~udt Pp-Ll~vdt 



AQjkM-(u-\-Ldx)dt Qg-Mmz(v+MdxW 



AK-AL zz(u+ldy)dt 

 AS -ALr.(u-\-hdz)dt 



pix-l\-wdt 

 q(P my,-(w-\-Ndx)dt 

 r g-nvz. (w*\- n dy)dt 

 s<r-lo-(w-\-vdz)dt 



R r- L n ziv-Y m dy)dt 



$ s -Ll-{y+ \y.dz)dt 

 Hinc ergo ternae coordinatae pro his quatuor punctis 

 «r, <£>, ^ et <r eruntj 



AV-x+udt^ Vpry+vdt; p7czz-\-wdt 



RQpx-\-dx-\-(u+Ldx)dt\ Q<py-\-(v-±Mdx)dt-, q<P~z+ (w+Ndx)dt 

 AKzx-\-(u-\-ldy)dt ; Krzy-\-dy-\-(v-\-mdy)dt^ r g-z-\-{w-\ndy" dt 

 A^z-x-YiiiVhdz^dt \ Sszy+(v-\p.dz)dt; s crr.z+dz-\-{w-\- vdz)dt 



29. Cum igitur elapfo tempufculo dt anguli 

 pyramidis X, jjl, v et in puncta 7r, (f> ; £ et tr fint 

 translati , ipfa pyramis nunc pyramidem pariter triangu- 

 larem 7r(pfo- conftituet ; ideoque ob indolem fiuidi 

 efficiendum eft., vt foiiditas pyramidis m(Pg<r aequalis 

 fit foliditati pyramidis propofitae Ajjlko, feu — \dxdydz. 

 Totum ergo negotium huc redk , vt ibliditas pyrami- 

 clis TfCp^cr determinetur. Perfpicuum autem eft, llanc 

 pyramidem relinqui, fi a fotido prqnfygtr auferatur fbli- 

 dum pqrntyg ; quod pofterius folidum eft prifma bafi 

 triangulari pqr normaliter infiftens, et fuperne feclione 

 obliqua 7r^(J) truncatum. 



30. In huiusmodi autem prismata truncata tria 

 qnoque altenun folidum pqmtpgcr refoJui poteft, quae 

 funt : 



I. pqsn<p<r\ II. prsKgv', III. qrstygv 



Nn 2 ficquc 



