FEBRUARY. 
41 
dens. It is called Bambusa Simonii, and produces numerous stems wliicli 
grow 10 feet high in a season, and have the leaves 10 or 12 inches long, 
some of them striped with white and others quite green. Of Annuals, the 
Swan River Helipterum Cotula, a slender branching plant, with white or 
yellow flower-heads, and belonging to the race of “Everlastings,” will 
he probably the most useful. , T 
OUR MONTHLY CHRONICLE. 
The severity of the Weather during the 
first three weeks of the year has been a sub¬ 
ject of unusual interest to all classes, rich as 
well as poor, and not to horticulturists and 
meteorologists only, with whom even slight 
climatic variations have an importance which 
they do not assume in the eyes of other 
people. Karely, indeed, has the thermometer 
been known to descend so low in this country; 
and for the last half century the only instances 
of frost of similar intensity near London 
were in 1838, still remembered by many as 
Murphy’s year, and in December, 1860. On 
the 19th of January, 1838, the minimum ther¬ 
mometer at Chiswick registered 4|° below 
zero; on the 28th of December, 1860, 1° below 
zero; but on the morning of the 5th of 
January in the present year two instruments 
alike indicated 11° below zero, as the lowest 
point reached during the previous twenty- 
four hours—a degree of cold never before re¬ 
corded near London. Other thermometers in 
the neighbourhood indicated a similar tempe¬ 
rature, and even so early on the evening of 
the 4th as five o’clock, the thermometer was 
below zero. It may here be observed that 
there is much difficulty in obtaining a really 
accurate thermometer, simple as the instru¬ 
ment is, and that even when such an one is 
obtained, some care is necessary to prevent 
its indications being affected by radiation 
from buildings and other sources of heat, and 
by the mode in which it is hung. 
The late frost was most severe in the valley 
of the Thames, and it would appear that it 
reached its greatest intensity at Ch'swick, 
which lies in a sort of basin, with the high 
grounds of Acton and Ealing to the north 
and north-west, and with higher ground, 
likewise, to the south and east. Into this 
basin the cold air probably descends by its 
superior gravity, and accordingly frosts are 
there peculiarly severe, much more so than 
on the higher ground adjoining, and in spring 
they prove very destructive to fruit-tree blos¬ 
som where the trees are not protected. The 
common impression is that cold increases 
with altitude, and this is undoubtedly true as 
regards mountains and other considerable 
elevations above the level of the sea; but in 
the case of what may be considered mere de¬ 
pressions of surface, it is probable that the I 
greater weight of the cold air causes it to 
descend and produce a lower temperature in 
the valley than on the higher ground, whilst 
the warm air of the valley, being lighter, 
would float upwards and more than counter¬ 
act the mere effect of elevation—in fact the 
high ground would not be, as mountains are, 
cut off from the radiation of heat from the 
rest of the earth, but provided with a natural 
source of warmth in the air heated in the 
valley, both by the earth’s radiation and by 
the sun’s rays. Some experiments made at 
Chiswick a few years ago appear to confirm 
this view, for thermometers very carefully 
compared with each other and with the stan¬ 
dard instrument at Kew, and fixed at every 
5 feet on a pole 30 feet high, were found al¬ 
most invariably to register a higher tempera¬ 
ture during frosty weather towards the top 
of the pole than nearer the ground. 
At other places near the Thames the 
severity of the frost was greater than in 
parts of the country usually more cold : thus 
at Slough the thermometer fell to 8° below 
zero, at Staines to 7° below zero, at Cobham 
to 6.8° below zero, at Wallingford to 5° below 
zero, at Hammersmith and Maidenhead to 3° 
below zero, at Dorchester, Oxfordshire, to 2° 
below zero, at Maidvtone, on the Medway, to 
zero, and yet on the higher ground of Cam¬ 
den Town the thermometer did not fall below 
6.7°, whilst on the very summit of Notting 
Hill it was no lower than 9°. In Yorkshire 
Mr. May, of the Hope Nurseries, Bedale, re¬ 
corded a temperature of 5° below zero, and 
in other parts of the country the cold, though 
not so remarkable as near the Thames, was 
still very great, as will be perceived by the 
temperatures recorded at the following places: 
—Downham Market, 2° below zero ; Laver- 
stoke, Hants, 1° above zero; Leominster, Here¬ 
fordshire, 3°; Street, Somerset, and Brigg, 
Lincolnshire, 3.J° ; Sawbridgeworth, South¬ 
ampton, and Winchester, 4°; Berkhamstead, 
4.1°; Wimbledon, 5°; Cambridge, 8°; Wick¬ 
ham Market, Oakham, and Exeter, 9°; Ply¬ 
mouth and Bridport, 11°; Liverpool, 12° 
Norwich, 14°. In Scotland the thermometer 
also fell very low; thus with Mr. Anderson, 
of Meadow Bank, near Glasgow, it stood at 
4°, whilst at Haddington on the east coast it 
was no lower than 9°. Even Ireland, the 
