CLIMATE. 



19 



mountain ranges. January is a far colder month on tlie banks of the Thames than 

 in the Hebrides, and plants which the frosts of Middlesex would kill flourish 

 in these islands in the open air, even in midwinter.* Yet it happens but 

 rarely that the larger rivers become ice-bound, and a sight such as the Thames 

 presented in February, 1814, when it was frozen over above London Bridge, and 

 placards announced that there was a "safe pathway over the river to Bankside,"is 

 not likely to be seen again, since it was due in some measure to old London Bridge, 

 with its narrow arches, which now no longer obstructs the free passage of the river. 

 The winter temperature is mildest on the southern coasts of Devonshire and Corn- 

 wall, and there the myrtle and other sub-tropical plants flourish in the open air all 

 the year round. 



Snow and ice are known, of course, and the quantity of the former which 

 occasionally falls in Northern England and in the Scotch Highlands is great. 

 It is rare, however, for the thermometer to fall below 18° Fahr., and rarer still 

 for such a degree of cold to continue for any length of time. The difference 

 between the mean temperature of the coldest and warmest months hardly ever 

 exceeds 25° Fahr., and in South-western England it does not amount to 19° Fahr. 

 This is very little when compared with places on the continent, for at Paris 

 and Rome it amounts to 30° Fahr., at Berlin to 36° Fahr., and at Vienna to 

 40° Fahr. The daily range of the summer temperature in Shetland, the Orkneys, 

 and the Hebrides, which enjoy perhaps the most insular climate in Europe, is only 

 about 10° Fahr. On the west shore of Great Britain it rises to 12° and 14° Fahr., 

 in the central districts to 15° Fahr., and in the south to 20° Fahr. At Paris and 

 other places on the continent it is much higher. t 



The direction of the winds naturally exercises an important influence upon 

 temperature, no less than upon the distribution and amount of rain. The westerly 

 winds, which preponderate throughout the year, and more especially in summer 

 and autumn, carry with them the warmth and moisture of the Atlantic. Easterly 



Ramsay, " Physical Geography and Geology of the British Isles." 



t Meax Temperature in Degrees Fahrenheit. 



Latitude. 



Sandwich (Orkneys) . . 59°5' 



Aberdeen 57°9' 



Glasgow 55° 51' 



Edinburgh 55°27' 



Carlisle 5-l°ô4' 



York 53°51' 



Manchester 53°29' 



Liverpool 53°'25' 



Dublin ô3°21' 



Birmingham .... 52°55' 



Limerick 52''39' 



Oxford 51°46' 



Swansea 51°36' 



London 51°30' 



Gosport 50'47' 



Plymouth 50°22' 



Penzance SO"?' 



