TRANSACTIONS OF THE SECTIONS. 139 
average of ten years, it was 16:2° ; and for the same years in Guernsey exactly half, 
or 81°. The following tabular statement of the mean daily range of each month | 
will, however, be the best illustration of this :— 
Greenwich. Guernsey. Greenwich. Guernsey. 
Peerilees . IOI ae ONS? October. . 146° 2%. 67° 
Mayes se. “20'2. cer; Sd: November. 117 . . 61 
ede, . . Se0'S: ty EG December . 95 . 5 62 
ky st fee. eS 10% January. . 100 . . 64 
Ausush 6, 20:00. 100 February . 123 . . 71 
September. 198 . . 86 Marcel’ 22%) loan sae 8 
The difference thus indicated is total, and is connected with another, also very 
important, namely the total absence of night frosts in Guernsey. The effects on 
vegetation are very remarkable. 
The extremes of temperature in Guernsey also range within narrow limits. 
There has been no reading of an accurate thermometer recorded higher than 88°, or 
below 24°5°, 
2. Barometric pressure.—The fluctuations of the barometer in Guernsey are fre- 
quent, but moderate. The maximum height of the column is in September and 
December, and the minimum in October and April; and, as in England, the pres- 
sure is generally greater in summer than in winter. 
3. Winds.—The absolute force of the wind does not seem to be excessive, though 
squalls are frequent and violent. North-west winds blow, on an average, 1092 days, 
north-east winds 107, south-west 100, and south-east 50. North-east winds 
Bae in September, May, and March, the average being 123, 121, and 11} days. 
orth-west winds preponderate in August ; and in April north-east and north-west 
winds are equal. In no month is there an average of more than 63 days of south- 
east wind. During June, July, August, October, and January, nearly two-thirds 
of the weather is from westerly quarters ; and during March, May, and September, 
from easterly quarters. 
4, Rain-fall.—The mean annual rain-fall in Guernsey is nearly 35 inches, falling 
on 164 days. October is the wettest month, and January the month in which the 
number of rainy days is greatest. From May to August, inclusive, are the driest 
months, the total rain-fall being 81 inches; and from October to January the 
wettest, when 163 inches fall. More rain falls in the night than during theday. A 
continuance of twelve hours’ rain israre, and the finest days often succeed the worst 
mornings. Snow rarely falls, and when it does, is generally with a south-east wind 
late in the season. Hail occurs at all seasons, but not often very heavily. 
5. Cloud and Moistwre.—The air is very frequently clouded in Guernsey, but 
only partially. The mean cloudiness, of the year is about 53, a completely clouded 
sky being 10. The air is seldom saturated with moisture, though the mean humi- 
dity is ‘854. The extreme of humidity is in February, when the temperature is 
lowest. The driest month is August, when the temperature is highest. Dense 
sea-fogs are common in May and June; but the total number of days of thick 
weather in the year is not large. The dews are very heavy. 
6. Ozone.—The ozone-observations range over too short a period to be of much 
value, but the means during that period were not high, especially during the sum- 
mer months. September to January, inclusive, were the months of maximum ozone. 
JERSEY. 
The climate of Jersey differs from that of Guernsey much more than would be - 
expected from its close vicinity and similarity of form, elevation, and soil. The 
mean temperature is nearly the same, Jersey being 0°3° higher ; but the spring, sum- 
mer, and autumn are warmer than the mean, and the winter colder. Thus from April 
to October, inclusive, the mean of Jersey is one degree higher than in Guernsey ; and 
from November to January, inclusive, three-quarters of a degree lower. During . 
the other months the means correspond. The daily range differs considerably. Thus 
in December it is 17‘7° in Jersey, and in Guernsey only 7°; in January the figures 
are 7:1° and 6°7°, and in July 6°8° and 6°. August alone shows a small difference 
the other way, the range then being somewhat greater in Guernsey, and the mean 
temperature more than one degree lower. 
