M. Humboldt ori Isothermal Lines, 
The means given by the Mexican observations are a little dif- 
ferent from those given by the observations on the Cordilleras. 
When the differences and the coincidences amount to about a 
degree of Fahrenheit, they may be regarded as purely acciden- 
tal. The length of the day is more unequal in the SOth de- 
gree of latitude, but the perpetual snows do not descend 656 
feet lower than under the Equator. As the Cordilleras of New 
Granada, Quito, and Peru, present a great number of points 
where stationary observations have been made, I shall collect 
here the mean temperatures which M. Caldas ^ and I have de- 
termined with some certainty, and which all belong to a zone 
bounded by the parallels of 10° N. and 10° S. Lat. 
Alt. in 
Feet. 
Mean 
Temp, 
Alt. in 
Feet, 
Mean 
Temp. 
Coasts of Cumana, 
0 J 
^ 80.6 
i 82.4 
Alausi, 
Pasto, 
7970 
8308 
59!oO 
58.28 
Tomependa, Amazons R. 1279 
78.44 
Santa Rosa, 
8459 
57.74 
Tocayma, 
1581 
81.5 
Cuenca, 
8633 
60.08 
Antioquia, 
1666 
77.00 
Santa Fe de Bogota, 
8721 
57.74 
Neiva, 
1702 
77.00 
Hambato, 
8849 
60.44 
Caraccas, 
2906 
69.44 
Caxamarca, 
9381 
60.80 
Caripe, 
2959 
65.3 
Llactacunga, 
9473 
59.00 
Carthago, 
3149 
74.84 
Riobamba Nuevo, 
9482 
61.16 
La Plata, 
343T 
74.66 
Tunja, 
9522 
56.66 
Guaduas, 
3772 
67.46 
Quito, 
9538 
57.92 
La Meya, 
4225 
72.50 
Malbasa, 
9971 
54.50 
Medellin, - , 
4858 
68.9 
Plateau de los Pastes, 
10099 
54.50 
Estrella, 
5645 
65.84 
Les Paramos, 
11480 
47.30 
Popayan, 
5815 
65.66 
At the Inferior Li- \ 
Loxa, 
6855 
64.4 
mit of Perpetual V 
15744 
34.88 
Almaguer, 
7413 
62.6 
tual Snow, j 
Pamplona, 
8016 
61.16 
These thirty-two points are not insulated points, as balloons 
would be if they were fixed in the atmosphere at a perpendicu- 
lar height of 16,400 feet. They are stations taken on the decli- 
vity of mountains, upon that part of the solid mass of the globe 
which, in the form of a wall, rises into the higher regions of the 
atmosphere. These mountains, too, have at each height parti- 
* I have used the mean temperature and barometrical measurements published 
at Santa Fe de Bogota by MM. Caldas and Restrepo in the Semanario del N. R. de 
Granada,^ tom. i. p. 273.; tom. i. p, 93.— 34'!. 
/ 
