REPORT ON METEOROLOGICAL OBSERVATIONS AT WISLEY. 135 



Rain fell on 15 days to the total depth of... ... ... ... ... ... 2-67 in. 



(Equivalent to about 12^ gallons of water to the square yard.) 



Heaviest fall on any day 0*54 in. on the 30th 



The prevailing winds were westerly and south-westerly. 

 The average velocity of the wind was 6 miles an hour. 



There were 77 hours of bright sunshine, equal to 30 per cent, of the greatest 



possible amount. 

 There were 7 days on which no sunshine was recorded. 



December. — The very remarkable difference between the mean 

 temperature of October and that of November was followed by 

 another unusual change, inasmuch as December proved to be one of the 

 warmest Decembers experienced during the last forty years, and its 

 mean temperature was higher than the normal by 50°. The maximum 

 at Wisley was only once below 40° ; and the minimum in the 

 screen fell to freezing point on only four occasions, so that not only 

 were the days warm but the nights were relatively even warmer; on 

 the grass there was frost on nine occasions. The first half of the month 

 was continuously wet, rain falling every day, and during this period 

 nearly the whole of the rainfall of the month occurred; there were 

 nineteen days on which a measurable amount of rain fell, and four on 

 which an amount too small to measure was found in the gauge. The 

 amount of bright sunshine was decidedly below the average. About 

 the second week of the month there was some stormy weather, the 

 wind in some districts blowing very strongly. 



The results from Wisley are as follows : — 



Mean temperature of the air in shade 44°.3 



Highest „ „ „ 55°.3 on the 24th 



Lowest „ „ „ 25°.9 „ 28th 



Lowest „ on the grass 18°.5 „ 28th 



Number of nights of ground frost 9 



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

 deep. deep. deep. 



Mean temperature of the soil at 9 a.m 42°.l 42°.9 45°.5 



Highest „ „ „ 46°.4 45°.l 46°.9 



Lowest „ „ 37°.l 39°.5 43°.2 



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



represented by 100) 90 % 



Rain fell on 19 days to the total depth of 4-31 in. 



(Equivalent to about 20 gallons of water to the square yard.) 



Heaviest fall on any day 0*62 in. on the 14th 



The prevailing winds were from between south-west and south east. 

 The average velocity of the wind was 10 miles an hour. 



There were 32 hours of bright sunshine, equal to 13 per cent, of the greatest 



possible amount. 

 There were 12 days on which no sunshine was recorded. 



