LAND AND SEA BREEZES, ETC. 121 



and electricity, agents which produce rapid altera- 

 tions in the equilibrium of the atmosphere. The 

 land and sea breezes already referred to may be 

 frequently perceived on the shores of Britain dur- 

 ing the fine weather of summer, and are produced 

 by the same causes which operate on tropical 

 coasts. 



The westerly winds which blow upon our shores 

 are much more regular and continuous than any 

 others, and are, as is well known, greatly more 

 genial and healthful. Their causes are similar to 

 those of the trade-winds already adverted to. 

 The heated air over tropical lands rises upwards, 

 as already described, and while its place is taken 

 by cooler currents blowing towards the equator, 

 the warmer air ascending to a great height in 

 the atmosphere spreads itself to the north and 

 south, and as it parts with its superabundant 

 caloric falls again towards the earth, blowing 

 towards our western coasts laden with much of 

 the warmth of tropical lands, and with an abun- 

 dant supply of oxygen obtained from the luxu- 

 riant vegetation of 'the more favoured climates 

 from which it originally arose. 



. Thus the ocean and the atmosphere both have 

 their systems of circulation, and those systems 

 produce effects of vast importance in the economy 

 of nature, conducing in a marvellous degree to 

 the vitality and the enjoyment of animated beings. 

 The limits of this work do not permit more than 

 a very general view of those most interesting 

 natural phenomena, but even a general view is 



