THE WEATHER, AND WEATHER PROPHETS. 167 



along the whole length of that range into a broad swell, 

 propagated onwards as a wave across America and the 

 North Atlantic into Europe. No merely local action, 

 and no casual conjunction of circumstances, can be con- 

 sidered competent to produce so extensive and so 

 regularly recurring an effect. A mere inspection of 

 Admiral Fitzroy's interesting compendium of the state of 

 the barometer, &c., &c., over the area occupied by our 

 island and the neighbouring continental coasts, as re- 

 corded from day to day in the Times, will suffice to 

 satisfy any one of its occurrence in former years, and to 

 show that its character has been (so far at least, Nov. 

 21) fully maintained in the present (1864). 



(31.) If we are ever to make any material progress in 

 the prediction of the weather beyond " forecasts" of a 

 few hours, or it may be a whole day in advance, it can 

 only be by the conthiued study of such of its phases as 

 recur periodically, or of such as manifest a periodicity of 

 event, as distinct from that of times and seasons, with a 

 view to connecting them with their efficient physical 

 causes. Of this latter description we have an example 

 of one, and of its successful reduction under the domain 

 of philosophical reasoning, in the law of the rota- 

 tion of the winds. That the winds in their changes, 

 in a general way, *' follow the sun," i.e., have a ten- 

 dency to veer in the same direction round the com- 

 pass card with the sun's apparent diurnal course in 

 the heavens (from east round by south, west, and 

 north in the northern hemisphere, and reversely in tlie 

 southern), in continual succession back to the original 



