...-g-,. From the other equation follows S, = - | P, We have still to ascertain the strains S0i and S,3, which we are able to do by the equations of point (1), after having altered them in the same way : So, + g . S13 - Slf = 0, 8,4 + ^ - S13 = Pt. rm By which, in connexion with the above equations,...