METEOROLOGICAL OBSERVATIONS AT WISLEY, 1916. ' 103 
and freshness in a quite remarkable degree, and roses continued to 
bloom freely. 
The results obtained from the meteorological instruments at the 
Observatory in the Garden are as follows : 
Mean temperature of the air in shade . . . 55- 8° 
Highest ,, 716° on the 25th 
Lowest „ „ „ ... 335° „ 22nd 
„ „ on the grass 28 0 15th 
Number of nights of ground frost 6 
At depth of 
1 ft. 2 ft. 4 ft. 
Mean temperature of the soil at 9 a.m. . . • . 57- 7 0 58-3° 57-8° 
Highest „ „ 6i° 6i° 595° 
Lowest „ „ „ 54° 56° 56 0 
Mean relative humidity of the air at 9 a.m. (complete saturation being repre- 
sented by 100), 87 per cent. 
Rain fell on 13 days, to the total depth of 1*46 in. (equivalent to nearly 7 
gallons of water to the square yard). Heaviest fall on any day 0-35 in., on the 
1st. 
The prevailing winds were north-easterly and north-westerly. 
The average velocity of the wind was 4 miles an hour. 
There were 105 hours of bright sunshine, equal to 28 per cent, of the greatest 
possible amount. 
There were 2 days on which no sunshine was recorded. 
October. — With the commencement of this month the weather 
underwent a complete change in its character, and the generally quiet 
conditions which had prevailed right through the summer gave place to 
weather of a stormy and unsettled type, which continued with but little 
intermission until its close. As regards temperature, the first half of 
the month was unusually warm, the daily maximum at the Gardens 
being between 60 0 and 70 0 throughout, whilst the night temperatures 
were also abnormally high, and on many nights fell very little below 
60 °, so that the weather was uniformly mild throughout the twenty- 
four hours. On the 15th, however, a complete change took place, 
and the southerly winds which had caused these quiet conditions 
gave place to strong currents of a different type, that brought with them 
an abrupt fall of temperature, and occasional ground frosts at night, 
by which such plants as Gunneras and Dahlias were killed, although, 
notwithstanding the cold, the foliage of trees maintained its colour,, 
with scarcely any fall of leaves, right up to the end of the month. 
There was everywhere less sunshine than usual, but the deficiency was 
particularly marked in the western districts, where at this time of the 
year there is generally more sunshine than in other parts of the king- 
dom. At Wisley thirty per cent, of the possible amount was registered, 
but over Cornwall and Devon the percentage was in many places as 
low as twenty. Rainfall was everywhere in excess of the normal 
amount, and at Wisley the excess was nearly fifty per cent. ; but the 
north-eastern and eastern counties of England were the only districts 
in which the fall was normal. 
The results of the observations made at Wisley are as follows : 
Mean temperature of the air in shade . . . . 527 0 
Highest „ „„.... 67 0 on the 5th 
Lowest „ „ ... 27 0 „ 21st 
» » on the grass 19 0 „ 21st 
Number of nights of ground frost 8 
