DORSET MONTHLY RAINFALL, 1856-95. 155 



how seem to have terminated the rainfall month on the last day, 

 and not, as is the present practice, on the first of the ensuing 

 month. This want of uniformity is to be regretted, but the conse- 

 quent irregularity is not very serious. 



As the stations vary in number and locality, and the rainfall in 

 amount from one year to another, the monthly ratios have been 

 computed from all the stations of the year, equal weight being given 

 to each year and the results combined. These ratios are represent- 

 ative of the whole county, and are probably more correct than 

 if deduced from a single ideal station, had any such station 

 existed. 



The irregularity and seeming capriciousness of the fluctuations of 

 the seasonal rainfall in the same direction for several years in 

 succession, as in February in the decade ending 1895, when the 

 precipitation was less than half that of the previous decade, proves 

 how little dependence is to be placed on short averages. Many 

 years' additional observations will be needed to arrive at the true 

 relationship of the monthly rainfall, and there can be no approach 

 to finality for the present generation of observers. Meanwhile, 

 some interesting facts may be deduced from an examination of the 

 40 years under discussion. In this period a well-defined minimum 

 rainfall in May is counterbalanced by a maximum double the 

 amount in October. The rainfall increases from May to October, 

 and, with a slight break in December, diminishes from October to 

 May. It is in excess from September to January, while the 

 temperature of the air is declining, and in defect for the remainder 

 of the year. 



Comparing Dorset with Greenwich, which may be taken as a 

 typical inland station of the South of England, there is a falling off 

 in late spring and summer. The lowest relative precipitation, 

 being the same at both places, occurs two months later, and there is 

 no secondary maximum in July and August. The rain from May 

 to August does not much exceed the fall at Greenwich, perhaps from 

 a comparative absence of thunderstorms. It is considerably more 

 copious from October to February, the excess of winter rain being 



