325 



British Isles necessarily implies that the waters bathing our coasts 

 acquire a temperature which exceeds their mean temperature for the 

 season of the year at which the extension takes place. The tempe- 

 rature of the air over the sea, and finally of the air over the islands, 

 becomes sensibly increased. The entire temperature at any point 

 will thus depend chiefly on what it gains from sunshine, and from 

 the warm sea-air, and on what it loses by radiation. If the excess of 

 what it gains from sunshine over its losses by radiation be considerable 

 compared to its gain from the influence of the sea, the temperature 

 will depend principally on the latitude. If, on the contrary, the 

 thermal influence of the sea be very considerable, places at different 

 latitudes may possess nearly equal temperatures. It follows that 

 during cold winters we should expect a greater difference between 

 the temperatures of the southern coasts of Great Britain and Ireland, 

 and the remainder of their coasts, than during mild winters. It also 

 follows, that during warm winters the difference of temperature 

 between stations situated on coast and inland stations having nearly 

 the same latitude, should be greater than during cold winters. 



Although I have not yet finished all the calculations necessary for 

 the complete illustration of these conclusions, I have been enabled to 

 show that during some recent winters the observed results as to tem- 

 perature entirely conform to these laws. 



The mildness of the winter which has just passed away, has been 

 universally remarked, and Mr. Glaisher's returns for the meteorology 

 of England and Scotland during December 1857 fully illustrate the 

 matter. I have not yet received the returns for January and February, 

 but I feel assured that they will exhibit corresponding results. 



During December 1857 the temperatures of the coast stations 

 were as follows : 



North and West Coasts. 



(Orkney) Stornoway 46*1 



Elgin 45-3 



Liverpool 48*3 



Isle of Man . . 48-9 



51-2 



South Coast. 

 Helston 



Truro 49-3 



Teignmouth 48'8 

 Ventnor . . 49 '2 

 Worthing . . 48 '0 

 Hastings . . 47'3 

 Ryde 46'9 



o 



44-3 



East Coast. 

 Aberdeen. . 

 Arbroath . . 43'8 

 Pittenween . 4 5 '8 

 N. Shields . 45-6 

 Scarborough 45*0 

 Holkham . . 44-5 



Mean. . .487 



47-1 



44-8 



