LOCAL CLIMATOLOGY. 



75 



Latitude. 



■ 



Locality. 



Winter. 



Summer. 



Difference. 



Tatitiidp 60° 



Shetland Tsles 



38°. 5 

 16 .3 

 -38 .0 

 44 .6 

 6 .6 

 61 .3 

 55 .5 



54°. 

 60 .8 

 63 .0 



60 .4 



61 .9 

 70 .0 

 84 .6 



15°. 5 

 44 .5 

 101 .0 

 15 .8 

 55 .3 

 8 .6 

 29 .1 



do 





do 



Yakutsk 



T.atitndp .50° 



Penzance 



do 





T.atitndp 30' ArnHrii-n 



do 



Cairo 







And for examples on our own continent and one island from each 

 coast : 



Latitude. 



Locality. 



Winter. 



Summer. 



Difference. 



FROM the pacific. 



Latitude 40° 



Fort Humboldt 



45°. 2 

 32 .1 

 26 .1 



59 .2 



49 .8 



57°. 4 

 75 .9 



78 .1 



75 .2 



79 .9 



12°. 2 

 43 !8 

 52 .0 



16 .0 

 30 .1 



do 



Salt Lake 



do 



Fort ^Jadison 



FROM THE ATLANTIC. 



Latitude 30° 



"Rernaudas 



do 



Natches 







From these comparisons, it appears not only that the contrast between 

 summer and winter increases as we go inland, but also that it is greater 

 in the high latitudes than nearer the equator. 



This fact is important to the vegetable productions. Many of our most 

 valuable crops — being annuals — care nothing for the cold of the winter 

 if they can but have the requisite heat in the summer ; and others, which 

 are indeed perennial, as grapes, peaches, etc., can be protected against 

 frost in the inland winter, so as to produce most abundant and delicious 

 fruits in the summer; which, however, will not arrive at maturity at all 

 at the sea coast on the same isothermal line, for want of the greater heat 

 of summer which they find in their inland position. England, for 

 example, does not produce grapes, with an average for the year of 50°, 

 two at least more than our own , and winters no more than 40° against 

 our 25°.5 ; while in the neighborhood of Astracan and coastwise, with the 

 same general average for the year as England, and winters averaging 

 at least 8° or 10° colder than ours, and 25° colder than those of England, 

 "grapes and fruits of every kind are as beautiful and as luscious as in the 

 Canaries," although the vines must be buried several feet deep in the 

 winter to preserve them from frost. 



The temperature of places that have no great inland distance, is modi- 

 fied by the sea currents that may happen to flow near their coast. The 



