236 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



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



represented by 100) 89% 



Rain fell on 18 days to the total depth of 3-79 ins. 



(Equivalent to about 17f gallons of water per square yard.) 



Heaviest fall on any day 0 67 in. on the 8th 



The prevailing winds were from south-west and west. 

 The average velocity of the wind was 6^ miles per hour. 



There were 41-5 hours of bright sunshine, equal to 16 per cent, of the greatest 

 possible amount. There were 13 days on which no sunshine was recorded. 



December. — The weather of the closing month of the year was some- 

 what variable. During the first week it was windy and wet, but continued 

 mild. . Then a cold spell succeeded, with frosts and occasional hail and 

 snow, which in some districts fell heavily. The third week was again 

 milder, but the closing days of the month were cold, with snow in most 

 places, and with strong boisterous winds. The fall of rain varied in 

 different districts, but the amount of sunshine was generally in excess of 

 the average for the month. 



Mean temperature of the air in shade 37"-4 



Highest „ „ „ 54°-9 on the 3rd 



Lowest „ „ „ 21°-8 „ 27th 



Lowest ,, on the grass 11°'5 „ 28th 



Atift. At 2 ft. At 4 ft. 

 deep. deep. deep. 



Mean temperature of the soil at 9 a.m 40°-0 43°-2 46°'5 



Highest „ „ „ 47°-2 48°-9 50°-0 



Lowest „ „ „ 36°-l 39°-3 43°-l 



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



represented by lOOj 87% 



Rain fell on 20 days to the total depth of 1-76 in. 



(Equivalent to about 8^ gallons of water per square yard.) 

 Heaviest fall on any day ... ... ... ... ... ... 0*30 in. on the loth 



The prevailing winds were from south-west to north-west and north. 

 The average velocity of the wind was 65 miles per hour. 



There were 50-7 hours of bright sunshine, equal to 21 per cent, of the greatest 

 possible amount. There were 13 days on which no sunshine was recorded. 



The outstanding features of the year's observations made at the 

 Garden at Wisley will be most readily seen from the following diagrams. 



The upper portion of fig. 1 shows for each month the departures of 

 the mean temperature from the average. It was only in four instances 

 that the mean for the month fell below the average, and in no instance 

 was the defect large, whilst in seven months, five of which were consecutive 

 — July to November — the average was considerably exceeded. 



The lower portion of the diagram exhibits in a similar way the 

 remarkable dryness of the greater portion of the year, the deficiency of 

 rain being continued with two unimportant exceptions from February to 

 September. 



Fig. 2 shows the variations in the mean temperature from month to 

 month. The fall in the mean from January to February was due to the 

 unusual warmth of the first month rather than to the cold of February ; 

 but the unusual dip in the grass temperature mean in April was caused 

 by the sharp night frosts resulting from the clear skies, which were 

 so marked a feature of the weather of that month from a horticultural 



