CLIMATE. 
167 
Panama. The temperature of this Isthmus is probably more 
favorable to human life as compared with similar latitudes else- 
where. 
The mean equatorial temperature of the air in Asia is 82°.94 
« " " " in Africa, 85°. 10 
" " " " in America, 80°.96 
So that this continent is cooler under the equator than any 
other, owing to the abundance of sea surrounding it, and the 
more elevated character of the land. Similar causes lead to 
the depression of temperature on the Isthmus below what it is 
upon mainland of a like latitude. The curves of temperature 
appended are drawn from tables filled by the officers of the sur- 
vey while on duty, and also from extracts out of the log-books 
of United States vessels at the mouth of the Coatzacoalcos Kiver 
and at Mina-titlan. It must be remarked that these are the tem- 
peratures of the northern side of the Isthmus, while those on 
the southern side are somewhat higher. 
In Table I. is given the temperatures obtained by the U. S. 
Bomb-vessel Stromboli, lying at Coatzacoalcos Eiver in 1847. 
Table II. contains the temperatures obtained by the U. S. 
schooner Bonita in the same river in 1848. The same table 
contains also a lesser curve for a short period in May, 1851, ob- 
tained by the officers of this survey while at Mina-titlan. 
Table III. gives the temperatures at Mina-titlan and Coatza- 
coalcos in 1850-51, observed during the survey. 
From an inspection of these curves, it appears that the highest 
temperature obtained was on May 24th, 1847, and May 21st, 
1848, when it reached 98° : the lowest, the 31st December, 
1850, when it reached 62°. 
The mean temperature of a portion of May, 1847, 90° 
" " " early part of June, 1847, 88° 
" « " greater part of April,. ..1848, 83° 
" " whole of May, 1848, 88° 
" " " 1st half of June, 1848, 85° 
part of Dec. & Jan'y. 1850-51,. . .74° 
These curves were drawn from observations taken at different 
periods of the day ; thus, in 
