EEPOET ON METEOROLOGICAL OBSERVATIONS AT WISLEY. 57 



At 1 ft. At 2 ft. At 4 ft. 

 deep. deep. deep. 



Mean temperature of the soil at 9 a.m 41°-3 41°-6 43°-l 



Highest „ „ „ 45°'2 44°-5 43°-9 



Lowest „ „ „ 37°'7 39°-8 42°-0 



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



represented by 100) 88 % 



Rain fell on 14 days to the total depth of 1-47 in. 



(Equivalent to about 6| gallons of water to the square yard.) 



Heaviest fall on any day 0*44 in. on the 12th 



The prevailing winds were north-easterly and south-westerly. 

 The average velocity of the wind was 8 miles an hour. 



There were 75 hours of bright sunshine, equal to 21 per cent, of the greatest 



possible amount. 

 There were 10 days on which no sunshine was recorded. 



April. — The month opened with a continuation of the cold north- 

 easterly winds which had prevailed throughout the latter half of 

 March, and with them the temperature decreased until about the end 

 of the first week, when a frost unusually severe for the season was 

 very generally experienced. In Scotland the screened thermometer 

 fell many degrees below the freezing-point, and at Wisley 6° of frost 

 were registered. On the ground, however, the exposed thermometer 

 fell much lower, and in some southern districts early crops 

 received some damage. On the 5th the maximum temperature at 

 Wisley was only 34°, and it did not reach 37° on the 6th. Towards 

 the middle of the month the wind-current changed to south-west and 

 temperature conditions greatly improved, the thermometer rising on 

 the 15th to about 65°, and the milder weather continued to the close. 

 As regards rainfall, the month was decidedly wet over a considerable 

 portion of Scotland, but dry over the eastern half of the kingdom, 

 and average elsewhere; several places in eastern England had a 

 deficiency of 50 per cent. Bright sunshine was in excess of the aver- 

 age over a considerable portion of southern England, but much below 

 it over the greater part of the kingdom, and whilst in London City 

 there were 131 hours, and at Wisley 155 hours, the total at several 

 places in the north-west did not reach 100 hours. A little snow 

 fell in the early days of the month. 



The results from Wisley are as follows : 



Mean temperature of the air in shade 46°- 4 



Highest „ „ „ 65°-2 on the 15th 



Lowest „ „ „ 26°-3 „ 6th 



Lowest „ on the grass 20°-l „ 12th 



Number of nights of ground frost 11 



At 1 ft. At 2 ft. At 4 ft. 

 deep. deep. deep. 



Mean temperature of the soil at 9 A.M. ... ... ... 44°-7 44°'5 44°-5 



Highest „ „ „ 50°-8 49°-0 47°'5 



Lowest „ „ „ 370-6 390.5 420.6 



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



represented by 100) 78 % 



Rain fell on 11 days to the total depth of 1-62 in. 



(Equivalent to about 7^ gallons of water to the square yard.) 

 Heaviest fall on any day 0*52 in. on the 1st 



