1889.] 



On certain Ternary Alloys. 



477 



made in the lead-bath, theabscissse being in each case tin percentages, 

 and the ordinates zinc percentages for curve No. 1, and lead percent- 

 ages for curve No. 2. The two curves are not widely different at first, 

 but latterly curve No. 1 distinctly overlies No. 2. 



Fig. 5 represents the mean tin distribution curves derived from th e 

 preceding observations, No. 1 being that derived from the experiments 

 where the zinc present was double the lead, No. 2 where the two 

 metals were in equal proportions, and No. 3 where the lead was 

 double the zinc. The maxima obtained correspond respectively with 

 the ordinate values 4*7, 4*6, and 3*7, and are situated at about the 

 abscissa values 15, 14, and 12 respectively. The crossing points 

 (points of equal tin distribution as regards weight percentage through 

 the mass) are respectively close to 29*0, 28*5, and 25*2 per cent, of tin. 

 The gradient of rise towards the maximum and of fall subsequently 

 below the crossing point is steepest in curve No. 3 and least steep in 

 No. 1. 



The following tables contain the mean values graphically repre- 

 sented by these curves. 



