CLIMATE. 121 



or to 212 degrees Fahrenheit, would be sufficient 

 to raise the temperature of a pound of ice-cold 

 iron to about 1600 degrees Fahrenheit, or to make 

 the ice-cold iron red-hot. 



Although land and water areas may be situated 

 in the same latitude, and therefore receive equal 

 quantities of the sun's heat per unit of area, yet 

 the temperature of the land, and consequently of 

 the air over it, would become much hotter than 

 the temperature of the water, and of the air over 

 the water. 



The higher the temperature of an area, the more 

 rapidly it loses its heat. A land surface, when 

 heating, becomes hotter than a water surface when 

 similarly exposed for the same time to the sun's 

 heat. The land also, when cooling, loses its heat 

 more rapidly than the water ; the air over the land 

 becomes chilled sooner than over the water. 



Differences in the elevation of the land produce 

 differences in the climate. In general, an elevation 

 of three hundred and fifty feet will cause as great 

 a lowering of temperature as a difference of one 

 degree of latitude, or of about seventy geograph- 

 ical miles. Therefore, the same differences are 

 observed in passing from the base to the summit 

 of a high tropical mountain as are observed in 



F 11 



