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ON CLIMATE. 
ON CLIMATE. 
By E. J. LOWE, Esq., F.R.A.S. 
M ATURE has so provided for the welfare of the vegetable kingdom, that plants are differently com 
stituted for different climates. As an instance, let us only take the common Wheat of our own coun¬ 
try, and compare it with the Indian Corn of tropical climates ; the former growing in a temperate region 
has the ear of corn so constructed that the seed-vessels are placed in rows at a given angle to each 
other, so as to reflect the heat rays in a manner that nothing is lost, and, besides which, are placed on a 
slender stem which can be bent in the direction of the source of heat; on the contrary, to the Indian 
Corn nature has given an innumerable quantity of fibrous threads, to protect the seeds from being 
burned by the heat rays of a vertical sun, and this not being deemed sufficient, wide blades of grass 
surround the whole, and so completely are they shielded from the effects of a scorching sun, that the 
plant may be compared to an umbrella. From this we see the effect of temperature on plants, for if 
we remove the Wheat of England to where the Indian Corn grows, we receive no produce ; on the 
other hand, when we plant Indian Corn here, how seldom are we enabled to ripen the seed. Plants 
are also constructed in a peculiar manner with respect to the amount of moisture which they are likely 
to receive; the aquatic plants, always having a sufficient supply of water, are furnished with leaves 
more or less convex, which speedily shoot off the falling rain, whilst those growing in rocky places and 
on mountain-ridges, where but little moisture comes, have them concave, so that the few drops gathered 
by the passing shower, or from the dews of heaven, may all be conveyed to their roots. In such pro¬ 
visions of Nature we see the wisdom of the Creator on a grand scale. 
On nearing the equator we find plants, which in a higher latitude grew on plains or in valleys, now 
only flourish on mountains; and the nearer we approach the hot countries the higher must the moun¬ 
tains be, if we are to have the same plants growing there. To find a great diversity of plants, we must 
ascend a mountain, for after having arrived at such an elevation as to have overcome the meteorology 
of the locality in the immediate neighbourhood, in every yard that we ascend beyond this we find as 
many fresh species as if we had pursued our search the same number of miles in the direction of the 
pole; so that were there a mountain situated on the equator, of sufficient elevation and of peculiar con¬ 
struction, around and upon it would grow all the plants contained in the world. 
The temperature of a locality is affected by numerous causes, amongst which are the following :— 
1st, by the nature of its surface, i. e. whether land or water; 2nd, by its elevation above the level of 
the sea; 3rd, by its aspect; 4th, whether sheltered or exposed; 5th, by its soil, the nature and com¬ 
position of which, especially its colour, and its state of aggregation, have much influence—for on this 
depends its power of absorbing and reflecting heat and light, and of retaining or parting with humi¬ 
dity; 6tli, by its nearness to seas, or by its distance from them; 7th, by the predominance of certain 
winds ; and 8th, by the frequency of clouds, fog, &c. 
In ascertaining the temperature of a locality, we must not be content when we have learned the mean 
yearly heat, this will benefit us but little, for Stockholm and Quebec have a nearly similar mean tem¬ 
perature, yet the winter in Quebec is 11| degrees colder, and the summer 6 degrees warmer than that 
of Stockholm. Again, the mean yearly temperature of Philadelphia and St. Malo are the same, yet the 
coldest month of the former is 7 degrees below the freezing point, whilst that of the latter is 10 degrees 
above it. To succeed in the most perfect manner in the cultivation of foreign plants, Nature must be 
copied as closely as possible; if we find the plants to be treated with have come from a locality whose 
summer heat is 80 degrees and winter heat 40 degrees, we must treat them in the same manner; and 
if we find the temperature, on the average, in the day time rises to 70 degrees, and at night falls to 
30 degrees, why ought not we to imitate this also, instead of piling on the embers in the evening as if 
we thought, for instance, our plant from Pekin (whose hottest month is 84f) could not survive a tem¬ 
perature at a freezing point, whilst, had we suffered it to remain in its own country, it would have 
braved a month’s cold 7f degrees below the freezing point? 
It would be a difficult matter to make any alterations in the pressure of the atmosphere : luckily the 
same mean pressure at the level of the sea is maintained all over the earth, and the only difference be¬ 
tween the tropical pressure and that of our own country is, that in the former we have only a range 
of a third of an inch in the barometer, whilst in the latter we have three inches. According to Dr. 
Prout, in 30 inches of pressure (which is slightly above the mean), 23*36 inches is azotic gas, 6*18 
inches oxygen gas, 0*44 inch aqueous vapour, and 0*2 inch carbonic acid gas ; therefore, the three-inch 
range in the barometer is not due to the rain in the atmosphere ; for were we to have the whole 
amount of moisture annihilated, it would not make a difference of more than half an inch in the 
pressure of the atmosphere. 
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