478 METEOROLOGY. TEMPERATURE. 



of Dublin, in lat. 53o 23', is 49 .l^ F. ; and that of Edinburgh, in lai 

 550 57', is 48.40 F. 



An island, a peninsula, and the sea shore, consequently, enjoy a 

 more temperate and equable climate — the summers less sultry, the 

 winters more mild. On the shores of Glenarm, in Ireland, in lati- 

 tude 550, the myrtle vegetates throughout the year as in Portugal ; 

 it rarely freezes in winter ; but the heat of summer does not suffice 

 to ripen the grape. Under the very same parallel, however, at 

 Konigsberg, in Prussia, they experience a cold of 17° and 18° below 

 zero of Fahrenheit's scale in the winter. The ponds and little lakes 

 of the Feroe Islands, although situated in N. lat. 62°, never freeze, 

 and the mean winter temperature . is very nearly 40° F. On the 

 coasts of Devonshire, in England, the winters are so mild, that the 

 orange-tree, as a standard, will there carry fruit ; and the agave has 

 been seen to flourish, after having lived both winter and summer, 

 lor twenty-eight years, in the open air, uninjured. 



One of the grand characteristics of what may be called a mari- 

 time climate, is the less difference which occurs between the tem- 

 perature of summer and that of winter. At Edinburgh, for instance, 

 the difference only amounts to 19° F. ; at Moscow, which is nearly 

 on the same parallel, the difference amounts to 50^ F. ; and at 

 Kasan, (lat. 56°,) it is as much as 56.3o F. 



The influence of extensive continents, or remoteness from the 

 sea-board, does not seem merely to render a climate extreme, in- 

 creasing at once the heat of summer and the cold of winter. The 

 collective observations on temperature, made in Europe and in Asia, 

 show that the mean annual temperature decreases as we penetrate 

 more into the interior of continents towards the east. Humboldt 

 ascribes this diminution of temperature partly to the refrigerating 

 action of the prevailing winds. While the mean annual temperature 

 of Amsterdam (N. lat. 52° 22') is 49.6° F. , that of Berlin (N. lat. 

 520 31') is 47.40 F. ; that of Copenhagen, (N. lat. 55o 41') is 46.7° 

 F. ; and that of Kasan (N. lat. 55° 48') is but 35.9o F. 



The highest temperi\ture which has yet been registered, as occur- 

 ing in the open air, appears to have been observed by Burckhardt, in 

 Upper Egypt ; the thermometer indicated 47.5° cent., upwards of 

 118^ F. The lowest was seen by Captain Back, in North America, 

 when the thermometer fell to — .56^ cent., 68.° F. below zero. 



I II. DECREASE OF TEMPERATURE IN THE SUPERIOR STRATA OP THE 

 ATMOSPHERE. 



The temperature rises rapidly as we ascend in the atmosphere ; 

 places among the mountains always possess a climate more severe 

 as they are higher above the level of the sea. Even under the 

 equator, height of position modifies the seasons so much, that the 

 hamlet of Antisana, which is within one degree of south latitude, but 

 which is upwards of 13,000 feet above the sea level, has a mean 

 temperature which does not differ much from that of St. Peters- 

 burgh. Near it, but at a still greater height, the summit of Cyambe, 



