74B Col roy’s Experiments for 
equation, applicable at the level of the fea for the heat of 
84*1, is at moft only f^-inftead of 
Mr. bouguer found, that the rule which his expe- 
rience had furnifhed him with, for computing heights 
with the barometer between the ranges of the Cordil- 
leros, namely, that of deducing ~th part from the 
number of toifes expreffed by the logarithmic dif- 
ferences, which agrees nearly with the equation which 
1 have made ufe of in the table of computations, would not 
anfwer when he came to apply it at the level of the fea. 
He tells us, indeed, that the elafticities of the air, above 
and below, are there, as well as in Europe, exactly pro- 
portionable to its condenfations ; and even, that the in- 
tenfity of the elaffcic force, or fpring of the air, is every 
where equal in all places of the torrid zone that are con- 
fiderably elevated. The real condenfations in each place 
are proportionable to the weights of the fuperior columns 
caufing the compreffion ; thefe condenfations being in 
geometrical, the heights are in arithmetical progreffion. 
But below the fame law doth not take place ; becaufe the 
intenfity of the elaftic force is really confiderably lefs at 
the level of the fea, than it is at one or two hundred 
toifes above it, notwithstanding the effe£t of the heat, 
which fhould render it greater. It is to be obferved, that 
Mr. BOUGUERhath not given us the obfervations whereon 
he 
