S56 M. Humboldt on Isothermal Lmes^ and the 
Siaoliao-tsu-tao, 225 ly to the east of th^ same place. 
Siao-hai-thsing-tao, or the Small Isle of the Falhons, is 20 
ly to the south-east ; and 
Ta-hai-thsing-tao, 50 ly to the south-east of Ning-hai-hian. 
The gretit Chinese Geography contains nothing more on 
these islands, and does not even niention the most southern, 
which is named in the chart Kouang-^theou-taoy or the Isle of 
the Shining Head. According to other Chinese works, they are 
the^ntrepot of the maritime commerce between China and Corea, 
and the navigators who go from one of these countries to the 
other, frequently put into their harbours. 
Art. VIII.— 0/i Isothermal Lines^ and the Distribution 
Heat over the Globe, By Baron Alexander de Hum- 
ROLDT. (Continued from Vol. III. p. 20.) 
Having discussed the method of taking averages, and of 
reducing temperatures to general expressions, we shall now pro- 
ceed to trace the course of the Isothermal Lines on the surface 
of the Globe, and at the level of the sea. From a slight at- 
tention to the difference of climates, it has been remarked, more 
than a century ago, that the temperatures are not the same un- 
der the same parallels ; and that in advancing 70“ to the east or 
the west, the heat of the atmosphere suffers a sensible 'diminution. 
In pursuance of our method, we shall reduce these phenome- 
na to numerical results, and shew that places situated under 
the same latitudes do not differ, in American and Europe, by 
the same number of degrees of temperature, as has been vague- 
ly stated. This assertion would make us suppose that the iso- 
thermal lines are parallel in the temperate zone. 
r Natche%^ 
Funchal, 
I. Parallels of Georgia, of the State Oiotava^ 
of Mississippi, of Lower Egypt, \ 
and Madeira. j 
Lat. 
31° 
32 37 
28 25 
4.1 53 
36 48 
Mean 
Temp. 
64° 8' 
68 7 
69 8 
60 4 
70 0 
i. DilTerence, 
7 0 
4 1 
