816 
CLIDEMIA. 
makes a disagreeable sound, and is not wholly 
free from danger. If the horse be young, the 
fault may be mended, but, if otherwise, it can at 
best be but slightly alleviated. 
CLIDEMIA. A genus of beautiful, evergreen, 
tropical shrubs, of the melastoma tribe. Twelve 
species, all natives of the tropical parts of America, 
have been introduced to our hothouses; they 
vary in height from a foot to two yards; most of 
them are white-flowered; and about one half 
were formerly included in the genus melastoma, 
and may be regarded as sharing with it the po- 
pular name of American gooseberry-tree. 
CLIFFORTIA. A genus of ornamental, ever- 
green, Cape-of-Good-Hope, greenish- flowered 
shrubs, of the rosaceous order. The stem of the 
species longest and best known in Britain, is 
weak and about four feet high; its branches are 
numerous, spreading, rambling, and so feeble as 
to require some support; its leaves are heart- 
shaped at the base, broad and sharply-indented 
at the end, stiff, greyish, sessile, and alternate; 
its flower-buds rise singly from the bosom of the 
leaves, and have a shape, a size, and an appearance 
similar to those of the caper plant; and its flowers 
have a yellowish-green colour, and appear from 
May till the end of August. About 24 other spe- 
cies are known to botanists; and two-thirds of 
them may occasionally be seen in British gardens. 
CLIFTONIA. See BuckwuHeat-TREE. 
CLIMATE. We have learned from a more 
accurate acquaintance with different countries, 
that heat or cold depends not merely on geogra- 
phical latitude, but that local causes also pro- 
duce great variations from the general rule, by 
which a region lying near the equator should al- 
ways be warmer than one remote from it. By 
the word climate, therefore, we understand the 
character of the weather peculiar to every coun- 
try, as respects heat and’cold, humidity and dry- 
ness, fertility, and the alternation of the seasons. 
The nature of a climate is different according to 
the different causes which affect it, and the ob- 
servations hitherto made have led, as yet, to no 
definite result. In general, however, geographi- 
cal latitude is the principal circumstance to be 
taken into view in considering the climate of a 
country. The highest degree of heat is found 
under the equator, and the lowest, or the great- 
est degree of cold, under the poles. The tem- 
perature of the intermediate regions is various, 
according to their position and local circum- 
stances. Under the line, the heat is not uniform. 
In the sandy deserts of Africa, particularly on 
the western coast, also in Arabia and India, it is 
excessive. In the mountainous regions of South 
America, on the contrary, it is very moderate. 
The greatest heat in Africa is estimated at 70° of 
Reaumur, or 189$° of Fahrenheit. The’ greatest 
degree of cold at the poles cannot be determined, 
because no one has ever penetrated to them. 
The greatest altitude of the sun at noon, and the 
time of its continuance above the horizon, de- 
CLIMATE. 
pends altogether on the latitude. Without re- 
gard to local circumstances, a country is warmer 
in proportion as the sun’s altitude is greater and 
the day longer. The elevation of any region 
above the surface of the sea has likewise an im- 
portant influence on the climate. See article 
AutitupE. But the nature of the surface is not 
to be disregarded. The heat increases as the 
soil becomes cultivated. Thus, for the last thou- 
sand years, Germany has been growing gradually 
warmer by the destruction of forests, the draining 
of lakes, and the drying up of bogs and marshes. 
A similar consequence of cultivation seems to be 
apparent in the cultivated parts of North Amer- 
ica, particularly in the Atlantic states. The mass 
of minerals, which composes the highest layer of 
a country, has, without doubt, an influence on its 
temperature. Barren sands admit of a much 
more intense heat than loam. Meadow lands 
are not so warm in summer as the bare ground. 
The winds, to which a country is most exposed 
by its situation, have a great influence on the 
climate. If north and east winds blow frequently 
in any region, it will be colder, the latitude being 
the same, than another, which is often swept by 
milder breezes from the south and west. The 
influence of the wind on the temperature of a 
country is very apparent in regions on the sea- 
coast. The difference in the extremes of tem- 
perature is least within the tropics. The heat, 
which would be intolerable when the sun is in 
the zenith, is mitigated by the rainy season, 
which then commences. When the sun returns 
to the opposite half of the torrid zone, so that its 
rays become less vertical, the weather is delight- 
ful. Lima and Quito, in Peru, have the finest 
climate of any part of the earth. The variations 
in temperature are greater in the temperate 
zones, and increase as you approach the polar 
circles. The heat of the higher latitudes, espe- 
cially about 59° and 60°, amounts, in July, to 
75° or 80° of Fahrenheit, and is greater than that 
of countries 10° nearer the equator. In Green- 
land the heat in summer is so great that it melts 
the pitch on the vessels. At Tornea, in Lapland, 
where the sun’s rays fall as obliquely at the sum- 
mer solstice, as they do in Germany at the equi- 
nox, the heat is sometimes equal to that of the 
torrid zone, because the sun is almost always 
above the horizon. 
is, perhaps, the most uniform. A greater degree 
of cold than any we are accustomed to, seems to 
reign there perpetually. Even in midsummer, 
when the sun does not go down for a long time, 
(at the poles not for six months,) the ice never 
thaws. The immense masses of it, which sur- 
round the poles, feel no sensible effect from the 
oblique and feeble beams of the sun, and seem to 
increase in magnitude every year. 
remarkable; for there is the most undoubted 
evidence that these now deserted countries were, 
in former ages, inhabited. But, within a few 
years, large portions of this continent (if we may 
Under the poles, the climate 
This is very’ 
