[ *54 ] 
the Tame time, at three different heights. Pat the 
difference of the tabular logarithms of the heights of 
the quickfilver, at the i ft and 2d elevation L j at the 
2d and 3d, L". Imagine the thermometer at the ift, 
or loweft height, to have been -|- i6| ; at the 2d, 
i6| -{- 2 n i at the third, i6f — 2 m. 
Then the difF. between i'ft and 2d elevation, er L + -dL. L 
215' 
between 2d and 3d, — T ! m l_" 
215 
that is, the variations of height and denfity between 
each two of thefe three places, are nearly exhibited by 
two different logarithmics, the fubtangentsof which are 
B d — — B; B 4 - ~ — ** B ; therefore, the variations 
of height and denfity, throughout the atmofphere, 
are not reprefented by any one logiftic, when the 
temperature is unequal (as they would be, if, not- 
withftanding an inequality of temperature, the ab- 
folute elafticities were the fame in all parts) ; but by 
parts of different logiftics, at different heights; as 
they fhould be when the abfolute elafticities are 
different, in different parts, and can only be con- 
ftdered as uniform to a fmall diftance, above or 
below any height afligned. 
The mention of M. bouguer occurred fo na- 
turally upon this occafion, that I muft have re- 
proached myfelf with an impiety towards the afhes 
of a man, whofe memory will ever be dear to fcience, 
had I not attempted to vindicate his conjectures 
upon the point under immediate conftderation, from 
an animadverfion thrown out, in very general terms, 
with little tendernefs, and only juft in part. At 
5 
