( 136 ) 
the liquid is higher than that ot the vapour. The two sheets 
do not touch one another in such points.” It is true that the 
pressure for a point conjugated to such a point is the same, but 
dp. the ; ì dp 
_— is different from zero, as appears from the equation for ——. 
dy, dy, 
If we substitute in this equation y, = y,, we find: 
EP ED Rn 
CE ze («,—2,) egy eye 
p dy, 
r ’ : . . du 
The factor «,—v,, which also may be written depends on the 
dy, 
curvature of the g-surface, and in all cases in which the surface is 
only slightly bent it will have only a small value; but only in very 
special cases it will be rigorously zero. In general therefore we 
may assume, that this locus of the maximum liquid pressures does 
not deviate much from the locus for which y,—y, =0. If the pro- 
jections of the curves of equal pressure are drawn, the points of 
maximum pressure and the sections discussed by us are of course 
immediately to be determined, by tracing the tangents, passing through 
the angles of the triangle. 
Lee RUSS el ; : 
The value of — 5 assumes exactly the same shape it has for ¢ 
MRT dy, 
ah Ae 9 dus, 
binary system if either (r‚—t,) or TI are zero. The value of 7,—a, 
ay, 
vanishes in the first place if the quantity we have denoted by «, is 
zero, and in the second place if it is equal to unity. But in these 
cases we are really dealing with binary systems; in the first case 
with the pair 1,3 and in the second with the pair 2,3. In the first 
case we have: 
Deep 1 ae 
MRT dy, = (Y¥s—43) eee Tey | 
and in the second case, if 
1—2x,—y, = 1—2,—y,, or &,—a, =— (YY): 
Deed 1 2 8 F 
MRT dy, == CASA Een ze Un — 2 Won =f U ay ' 
The quantity uw’, — 2u’, + u',, has for the pair 2,3 the same 
signification as u’, for the pair 1,3, as is easily understood. 
Vie sl 
MRT dy, 
peculiar points, where «,—x, =O either inside the triangle or on 
The quantity assumes also this simple shape in the very 
one of its sides, and also in the points where vanishes. 
ay 
