188 



Mr. Hinds on Climate, S^c— Temperature. 



From 



A comparison of these data with those ah'eady given for 

 higher latitudes, will show that diminution of temperature on 

 elevation takes place more rapidly for given distances in the 

 temperate than in the tropic regions. Another table, also con- 

 structed by Humboldt, will furnish additional grounds for 

 some conclusive results. 



These are observations for elevations with a rapid ascent, 

 and accordingly having peculiar conditions : another disposi- 

 tion of surface occurs in extensive level countries having only 

 a slight elevation in one or more directions, perhaps rising in 

 a gradual ascent from the sea, or shoA^ing an inclined surface 

 to the different points of the heavens; the mean temperature 

 at their sea-level being known, on gradually ascending a de- 

 crease will happen ; but, as stated by Mr. Kirwan, in different 

 proportions according to the degree of elevation. Taking a 

 height of 200 feet, if the ascent is so gradual as not to exceed 

 six feet in a mile, the diminution in the mean annual tempe- 

 rature will be only 7}- th of a degree ; if 7 feet in the mile, -^rd ; 

 13 feet, /yths; and 15 feet, ^. 



Where observations differ so much, and where those made 

 at one place are at variance m ith others made under similar 

 circumstances at the same, and even maintain an irregularity 

 through different steps in their ascent, it is impossible to draw 

 any safe practical conclusions. The only plan, where a neces- 

 sity exists, is to make such allowances as known facts war- 

 rant ; supposing at the time that it is beyond our power to 

 obtain results for ourselves, and that none have been already 

 made. Within the tropics the table of Humboldt can be 

 used. In the case of Quito we took the mean of its height. 



