2i6 SCIENCE PROGRESS 



the very rigid connection between these two meteorological 

 elements. 



In no less degree is this the case for the south-west coast 

 of Australia, for Albany (one station) and Perth district (four 

 stations) show distinct rain beats in those years when the pres- 

 sure over this region and the whole of Australia was deficient. 



In our own islands the same story holds good, only, as I 

 have previously pointed out, the duration of those changes is 

 not the same as in the two areas which have just been con- 

 sidered. The pressure changes are here compared with two 

 districts, termed by the Meteorological Office " Midland Coun- 

 ties" and " England, South." The curves here shown represent 

 the rainfall variations as deduced from ten rain-gauges in the 

 former and seven in the latter district. The very close corre- 

 spondence of these curves with that for pressure at Oxford — a 

 representative of English pressure variation from year to year — 

 endorses for this region the deduction pointed out above. 



Now the reader must not imagine that in every part of the 

 world a decrease of pressure means an increase of rainfall. It 

 can, and does, often happen that in some regions excess of high 

 pressure means excess of rainfall. This is brought about by the 

 fact that this pressure condition may be very favourable for the 

 particular rain-bearing air current for some areas. In discussing, 

 therefore, the rainfall of any part of the world in relation to 

 pressure, this fact has to be borne in mind. It is on account of 

 this, among other reasons, that the rainfall problem is so much 

 more complicated than that of the pressure one ; and the reader 

 will, I think, agree with me that it becomes imperative to 

 thoroughly understand the latter before proper consideration 

 can be given to the former. 



The existence of these alternate high and low pressure 

 conditions will call for a considerable amount of work on the 

 part of the meteorological representatives of different areas. 

 It will be their duty to study the effects of these changes in 

 the rainfall of their immediate localities, and find out how 

 the " normal " conditions — conditions, by-the-bye, which seldom 

 actually exist — are thereby influenced. The old saying — 



Be it fine or be it wet, 



The weather '11 always pay its debt — 



has therefore so far a great amount of truth in it, and, as will 



