384 Mr. Harvey on the effects of the density of air 
Experiment for Mexico, elevated 1253 fathoms above the 
level of the Sea. 
Place. 
Mean Temp, 
during the 
Experiment. 
Mean 
Pressure. 
Number 
of Days. 
Daily rate 
of K. 
Daily rate 
of L. 
Vera Cruz 
54° 
30 in. 
5 
— 5". 9 
+ 4".8 
Mexico 
54° 
23 in. 
4 
— 4".o 
— o". 2 
If we again conceive a set of chronometers removed from 
the level of the ocean to Santa Fe de Bogota, or to the still 
loftier city of Quito, at which latter place the mean altitude 
of the mercurial column is 21 inches, the alterations of rate, 
recorded in the next table, will be found to result from the 
diminished pressure. 
Experiment for Quito, elevated 1603 fathoms above the 
level of the Sea. 
Place. 
Mean. Temp, 
during the 
Experiment. 
Mean 
Pressure. 
Number 
of Days. 
Daily rate 
of H. 
Daily rate 
of C. 
Level of 
the ocean. 
O 
00 
* 
30 in. 
4 
+ 
00 
b 
+ 3".o 
Quito 
47° 
21 in. 
5 
+ 14".2 
+ 6".2 
Four chronometers were afterwards placed in air cor- 
responding in density to 15 inches of mercury, being nearly 
the altitude of the barometer on Chimborazo, when the 
results recorded in the following table were produced. 
