METEOROLOGICAL OBSERVATIONS MADE AT WISLEY. 



55 



Jane. 



Mean temperature of the air in shade . 

 Highest temperature of the air in shade 

 Lowest temperature of the air in shade 

 Lowest temperature on the grass . 

 Number of nights of ground frost 



8o'2° on the 19th 

 40*2° on the 3rd 

 34*2° on the 3rd 

 None 



58-2° 



1 ft. 



At 



depth 

 2 ft. 



of 



4 ft. 

 56-4° 

 58-7° 



54'9° 



Mean temperature of the soil at 9 a.m. . 

 Highest temperature of the soil at 9 a.m. 

 Lowest temperature of the soil at 9 a.m. 



60-3° 

 65-5° 

 56-7° 



587° 

 61 -9° 



56-2° 



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

 being represented by 100), 76%. 



Rain fell on 19 days, to the total depth of 2*52 inches (equivalent 

 to about 11 J gallons of water to the square yard). Heaviest fall on 

 any day 071 inch, on the 7th. 



The prevailing winds were south-westerly and westerly. 



The average velocity of the wind was 7 miles an hour. 



There were 216 hours of bright sunshine, equal to 44 per cent, 

 of the greatest possible amount. 



There were 2 days on which no sunshine was recorded. 



July. — The month opened and closed with cool cloudy weather, 

 a warm spell occurring during the second week, and another near the 

 beginning of the last week and lasting for a few days. The highest 

 temperature of the month at Wisley was 87 degrees and occurred on 

 the 12th and again on the 15th, but in contrast to these warm days 

 the maximum on the 19th did not reach 60 degrees and the minimum 

 fell below 45 degrees, the thermometer exposed upon the grass falling 

 in the night to 33 degrees — an abnormally low reading for July. The 

 fall of rain at Wisley was not great, but in many parts of the country 

 it greatly exceeded the average ; in some parts of Hertfordshire in a 

 thunderstorm which occurred on the 23rd rather more than 3 inches 

 fell, and damage was done to g r owing crops. At a few places, not 

 usually the most sunny, the average amount of bright sunshine was 

 recorded, but over the greater part of the Kingdom it was very deficient. 

 The Wisley record was 150 hours for the month, only 44 per cent, of 

 the amount registered in the corresponding month of 1911. In July 

 1910 the total was only 121 hours, but that month and the one now 

 under review were the least sunny Julys during the period covered by 

 the Wisley observations. The combined result of the warm periods 

 near the middle of the month and of the small daily range of 

 temperature generally was a mean for the month very close to the 

 normal. 



The results from the observations made at Wisley are shown in 

 the following table : 



