294 Beviews and Notices of BooJcs, 



rence, are Strathmore, Stratliearn, the Lothians, and the Merse 

 in Berwickshire ; and where it occurs least frequently are the 

 northern islands." 



The temperature of 70°"0, the occasional occurrence of which 

 is necessary for the proper ripening of wheat, is shown to have 

 occurred only once in Orkney, and twice in Shetland and the outer 

 Hebrides during the period. It is of most frequent occurrence in 

 Berwickshire, the Lothians, Fife, Strathmore, and along the Moray 

 Firth ; in other words, in the best wheat-producing counties. 



The second paper, also by Mr Buchan, on the " Isothermals 

 of the British Isles in January and July," is of great value, and 

 is accompanied by a beautiful map in colours, engraved by the 

 Messrs Johnston, Edinburgh. The results are given in the 

 following extract : — 



With regard to the lines of equal summer heat, there are one 

 or two points of some interest which may be pointed out. The 

 most noticeable of these points is the general slope of the lines 

 from north-east to south-west, thus indicating a higher summer 

 temperature in the east as compared with the west of the British 

 Isles. This is occasioned by the general direction of the wind in 

 July being from the Atlantic Ocean, which at this time of the 

 year is colder than the land, and also by the greater amount and 

 less height of the clouds in the west as compared with the east. 

 The curving northward of the lines in the centre of England is 

 deserving of attention. This is owing to the circumstance, that 

 it is only this part of the island which is broad enough to allow 

 of the central parts acquiring so much of a Continental summer 

 climate as to give a decidedly northern flexure to the lines. The 

 southern part within the isotheral of 64°-0, of which London may 

 be said to form the centre, is interesting as being undoubtedly 

 the hottest district in the British Isles during summer, and con- 

 sequently that part best fitted for the culture of exotics which 

 require a high summer temperature. The colder summer climate 

 of the south coast, as compared with the district immediately to 

 the north -of it, just referred to, is caused by the moderating in- 

 fluence of the sea which flows round it. The whole of the British 

 Isles south of the Dornoch Firth and Skye may be considered as 

 suited to the successful cultivation of wheat and the finer cereals, 

 except those districts where the rainfall is excessive or the eleva- 

 tion too great. 



" The most noticeable point with respect to the lines of equal 

 winter temperature is the crowding of the high temperatures in 

 the western, and particularly the south-western, parts of the 

 British Isles. Ireland and the peninsula of Cornwall, being, as 

 it w^ere, more completely bathed in the warm waters of the Gulf- 

 Stream during the winter months, exhibit for this time of the 



