42 Rankin and Wright — Ternary System CaO-Al^O-SiO^. 



pound or component in ternary solutions ; if there is a break in 

 the continuous slope of a mountain side, then the slope from 

 the break down to the foot of the mountain represents 



Fig. 10. 





.■>^ : "^i''SSBjH 













Si ° 2 IS 







■i% 





^m. ■ 













L Al 2 o 3 | 





I 



Fig. 10. Photograph, of solid model showing relation of binary systems 

 CaO-Al 2 3 and Al 2 3 -Si0 2 to the ternary system. 



melting temperatures of an unstable compound in ternary 

 solutions; the valleys between mountains represent boundary 

 curves ; the points where the rivers in three valleys meet to 

 form a lake is a eutectic point, but if two rivers meet at a 

 point where they unite to form a single river, then that point 

 is a quintuple point but not a eutectic. 



