472 
CLIMATE, HORTICULTURE, AND AGRICULTURE. 
knowledge. Nay, we are unwilling to admitthat 
any such terms as theoretical knowledge can 
be applied properly to anything. If theory be 
based on experience, it is theory, but the 
knowledge is practical. However, we must 
proceed with our subject without disputing 
upon mere words ; we make this one objection 
at the outset, because we prefer to start on a 
fair and proper foundation, and not begin 
building our house downwards; and as we 
intend to give Mr. Daniell the credit of much 
that he has written, though we cannot agree 
with all. He observes further — 
" The science of Horticulture, with regard 
to climate, will be best considered in two 
divisions : the first comprises the methods of 
mitigating the extremes, or exalting the ener- 
gies, of the natural climate in the open air; 
the second embraces the more difficult means 
of composing and maintaining a confined 
atmosphere, whose properties may assimilate 
with those of the natural atmosphere in inter- 
tropical latitudes. I shall commence my 
observations with the former. 
" The basis of the atmosphere has been 
proved to be of the same chemical composition 
in all the regions of the globe. All the 
varieties of climate will therefore be found to 
depend upon the modifications impressed upon 
it by light, heat, and moisture, and over these, 
art has obtained, even in the open air, a greater 
influence than at first sight would appear to be 
possible. By judicious management the cli- 
mate of our gardens is rendered congenial to 
the luxurious productions of more favoured 
regions, and flowers and fruits from the con- 
fines of the tropics, flourishing in the open 
air, daily prove the triumphs of knowledge 
and industry." 
Here again we are disposed to question the 
application of the term " open air." The 
gardener accomplishes his task by changing 
the nature of the atmosphere, so that, strictly 
speaking, Mi-. Daniell is wrong. The pro- 
ductions on a south border, under a south wall, 
are not in the open air ; the wall itself is an 
obstruction to the open air, for if the wall were 
not present, the north wind would blow on the 
productions, and it would be easily 6een that 
those plants which flourish when protected 
against the north wind, would be destroyed in 
the open air. It is this silly blunder which 
has led many into the error of supposing 
that a plant is acclimatized, when it is 
only the temperature of the situation that is 
changed. 
In horticulture we have constant directions 
to "sow in a warm border," to plant "in a well 
protected spot," "to cover up from frost," 
and so on. Horticulture is a science the 
very elements of which teach us to counter- 
act the effects of the open air, and that cannot 
be called allowing plants to flourish in the 
open air. It is true, we know what it means; 
but, in treating of these subjects, we cannot 
be too precise, because the whole gist of the 
question turns upon the one great fact, that 
the Horticulturist's business is to defeat the 
mischief which plants would be subject to if 
they were really placed in the open air, 
or, as Mr. Daniell says, very truly, of the 
labours of the gardener, "T>y judicious ma- 
nagement the climate of our garden is 
rendered congenial to the luxurious produc- 
tions of more favoured regions ;" but the 
farmer, who really grows his productions in 
the open air, follows the gardener in all his 
operations but the changing of the climate, 
and he would now find the difference between 
the mercy of the " four winds of heaven," 
and the advantage of shutting out the north 
and the east, and relying on the genial 
breezes of the south and west only. If the 
open air means anything, or the term 
expresses anything, it must be the free unin- 
terrupted air; and all the farmer's or agricul- 
turist's science is comprised in making the 
most of his productions under such circum- 
stances ; and his agriculture is not carried on 
under south walls, hedges, or palings, that 
change the climate ; and the consequence is, 
that all his productions must be so far hardy 
as to require no artificial means to check the 
winds. His field is an open space, and all 
his labour and science must be concentrated 
in the management of the soil, and the regu- 
lation of his seasons of sowing, clearing, 
mowing, draining, and operations on the soil 
itself. The horticulturist keeps off the winds 
that are injurious, the sun where it is too 
hot, the rain where it is in excess. To follow 
Mr. Daniell through some of his more scien- 
tific reasoning : — 
" The amount of evaporation from the soil, 
and of exhalation from the foliage of the 
vegetable kingdom, depends upon two circum- 
stances, the saturation of the air with mois- 
ture, and the velocity of its motion. They 
are in inverse proportion to the former, and 
in direct proportion to the latter. 
" When the air is dry, vapour ascends in 
it with great rapidity, from every surface 
capable of affording it, and the energy of this 
action is greatly promoted by wind, which 
removes it from the exhaling body as fast as 
it is formed, and prevents that accumulation 
which would otherwise arrest the process. 
" Over the state of saturation, the Horticul- 
turist has little or no control in the open air, 
but over its velocity he has some command. 
He can break the force of the blast by arti- 
ficial means, such as walls, palings, hedges, or 
other screens ; or he may find natural shelter 
in situations upon the acclivities of hills. 
