REPORT ON METEOROLOGICAL OBSERVATIONS, WISLEY, 1913. 55 



was noteworthy because of the havoc it wrought over the southern 

 half of the kingdom, where its passage was marked by severe thunder- 

 storms and very heavy rain. These unsettled conditions were due 

 to the passage of a succession of centres of disturbance along a west 

 to east path, which as a rule lay over the northern half of the kingdom ; 

 and it was owing to this that the prevailing winds were from southerly 

 and westerly points of the compass, with weather warmer than is 

 usual in March, and a rainfall generally in excess of the average. 

 At Wisley there were two or three sharp ground frosts, and on the 

 night of the 17th the exposed thermometer laid upon the grass fell 

 16 degrees below the freezing point ; but on the other hand there 

 were not many days when the screened thermometer did not rise in 

 the day-time to above 50°, and there were only five nights in which 

 it fell to freezing point or below. 



In some parts of the kingdom the fall of rain was greatly in excess 

 of the average ; everywhere it was so to some extent, but over some 

 parts of the Midlands the fall was nearly three times as much as the 

 usual amount. The amount of bright sunshine varied somewhat, 

 some localities getting more and others less than the average ; but, 

 as is not seldom the case when the rainfall is large, the amount of 

 sunshine was, generally speaking, nearly normal, the differences from 

 the average being small in either direction. 



The records at Wisley show : 



Mean temperature of the air in shade 



. 44-4° 



Highest „ „ „ „ . . 



.57° on the 6th 



Lowest „ „ „ . . 



. if „ 25th 



Lowest „ on the grass 



. 16° „ i8th 



Number of nights of ground frost . 



. II 





At depth of 





I ft. 2 ft. 4 ft. 



Mean temperature of the soil at 9 a.m. 



. 43-2° 42-9° 43-9° 



Highest 



. 45° 44° 45° 



Lowest 



. 40° 41° 42° 



Mean relative humidity of the air at 9 a.m. (complete saturation being 

 represented by 100), 89 per cent. 



Rain fell on 20 days, to the total depth of 2'56 in. (equivalent to about 

 12 gallons of water to the square j^ard). Heaviest fall on any day 0-36 in., on 

 the 28th. 



The prevailing v,Ainds were south-westerly. 



The average velocity of the wind was 11 miles an hour. 



There were 102 hours of bright sunshine, equal to 28 per cent, of the greatest 

 possible amount. 



There were 5 days on which no sunshine was recorded. 



A'pril. — ^With the opening of this month the character of the 

 weather underwent for a time a change, and became somewhat more 

 settled. During its earlier days it was generally dry but dull, and 

 there was not a great deal of wind ; then followed another stormy 

 period, gales succeeding each other in quick succession, with heavy 

 falls of rain and occasional snow, which in some districts was heavy 

 enough to cover the ground to depths of from three to six inches. 

 The heaviest of these snowfalls occurred with a soiiiherly wind , which, 



