VISCOSITY STUDIES OF SYSTEM CaO‐MgO‐Al2O3‐SiO2: II, CaO‐Al2O3‐SiO2*

Viscosity data are presented covering those compositions in the CaO-Al2O3-SiO2 system which are liquid at 1500°C. The pattern of isokoms on the CaO-Al2O3-SiO2 face of the compositional tetrahedron which represents the CaO-MgO-Al2O3-SiO2 system is a system of lines which roughly parallel the lines along which the lime content is constant. There are, however, considerable deviations from this parallelism in regions of very low and very high alumina content.