379 
into each other by’ means of two cusps in the way indicated in 
fig. 5’). Finally it may still be pointed out that it is possible that in 
the last case the denominator passes through zero, which would 
bring about a combination of the figures 4 and 5. 
If we now apply the results obtained here to our original case 
indicated in fig. 1, we arrive easily at the correct result, when we 
omit in our thoughts first the three-phase line for FeC, + L + G, 
and then that for Fel + L+4G. We then get two intersecting 
figures, in which we can easily distinguish the stable equilibria from 
the metastable ones. 
Fig. 6 gives the P,7-projection for the case that we have twice 
the same type as fig. 4. 
i 6 
Fig. 6. ‘ 
The three-phase lines for C-+FeC+G and C+ Fe U, + G 
intersect in A, where a new quadruple point is formed, from which 
two more three-phase lines start, viz. hk for C + FeC + FeC, and 
he for FeC + FeC,+G. The point & is the point of intersection 
for the three-phase line bim'g for C + FeC + L, and of the three- 
1) Comp. the paper of Dr. ScHEeFFEeR, These Proc. p. 389. 
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