[ 2 g 9 ] 
, „ CAxA/3 f CAxA)9 
negative, the expremon ig ' A ' __~g 3 becomes — ca + Ag ' 
And there is no place in the atmofphere where the 
preffure is the fame in one condition as the other. 
But it is, at all heights, greater in the warmer 
condition (by 5 th of this). 
If the point Qfall below the central ordinate CK, 
(fig. 7 .) and the fubtangents / 3 L, /3M, be reciprocally 
as CF, CK, the points (3 and C will coincide, and B 
will go off to an infinite height. 
If the greater fubtangent /3M be lefs than to be 
(3L as the greater denfity CF to the leffer CK, 
/ 3 will be found below C, and the ordinate /3E is 
not one of thofe, by which the denfity of the air, 
at any height, in either condition, is reprefented. 
The expreffion is more than infinite, the 
denominator being negative ; and there is no height 
at which the preffure is the fame, in both conditions 
of the atmofphere ; but it is at all heights lefs in 
the warmer condition (by 5 th of ths). But when- 
ever QJalls below the fuperficial ordinate, whether 
it be above or below the central ordinate, if /3M be 
lefs than to be to /3L as AD to AG, and greater 
than to be to /3L as CF to CK, (3 will fall between 
C and A, and an equality of preffure, in both con- 
ditions of the atmofphere, will take place at a finite 
height, determined as above. 
If Q ever falls above the fuperficial ordinate 
through A, (3 will be more above it, and B will 
be below the earth’s furface, and there will bd 
no height at which the preffure will be the fame j 
Vol. LX1V. P p bjat 
