THE COTTAGE GARDENER. 
[January 17 
212 
Plumbago capensis : blue. Not a climber, but docs well against a 
pillar. 
Tropceolum pentaphyllum : green and red. 
“ Lobbianum : orange and red, &c. 
The last-named is not valued as it ought to be, as 
a free winter bloomer. R. Eish. 
IIOTHOUSE DEPARTMENT. 
EXOTIC ORCHlDACEiE. 
Moistening the Air of the Orchid Houses. — All 
plants under glass, when growing, thrive much better, 
and continue more healthy, if the air is kept in a 
moist state. Hence good gardeners, in this age of 
improved skill, are constantly, when the objects 
under their care are progressing in growth, throwing 
water upon the Hues, pipes, walls, and pathways, to 
create a humid atmosphere, and only withdrawing it 
when their fruit-bearing plants — such as pines, 
grapes, peaches, nectarines, &c. — begin to change the 
colour of their fruits. 
If common stove and greenhouse plants, and even 
fruit-trees, require a moist atmosphere, when in a grow¬ 
ing state, how much more must the tribes of plants, 
about whose culture we are now writing, require it, na¬ 
tives as they are of countries and localities, the atmo¬ 
sphere of which is constantly loaded with watery va¬ 
pour? We have been assured, by several travellers who 
have visited the South American continent, that the 
air where orchids are mostly found, is so full of parti¬ 
cles of moisture, as to give the country the appearance 
of being completely enveloped in mist — so much so, 
during the early part of the day, as almost to obscure 
the light of the sun. This mist bathes the plants 
completely, wetting them as thoroughly as if they 
had been dipped in water. The sun, however, being 
nearly vertical, and having great power by the middle 
of the day, clears away the mist, and dries the leaves 
of the trees on which the orchids grow. Still, a con¬ 
siderable amount of invisible moisture remains in 
the shady recesses of the forest, nourishing the or 
chids, and causing them to grow rapidly, and acquire 
strength to produce their flowers. This excessive 
humidity arises, no doubt, from the large surface of 
the rivers and lakes being acted upon by the fierce 
rays of a tropical sun. In such a climate, orchids 
abound. As the traveller advances towards the 
mountains, where the atmosphere is drier, the or- 
eliideae disappear. These natural phenomena in the 
atmosphere where these plants exist, show to us the 
necessity of imitating, as far as we can, such an at 
mosphere. It is our intention, this week, to show 
how it may be done, at least sufficiently so to cause 
the plants to grow well. 
At page 64 of this volume, we described the mode 
of heating, combined with means to supply moisture 
to the internal air of the bouse : but though that 
will afford a considerable amount of moisture, yet 
in the growing season it will not be sufficient. We 
also described an additional source of moisture, by 
having shallow cisterns, used as shelves, filled with 
water, under the plants. These cistern-shelves will 
indeed be a great lieli) to tbe plants, as the air will 
take up moisture from the water, at a time when the 
tanks, by not being required to be heated, owing to 
the natural heat of summer, will not give out any 
steam or vapour. Still, with all these helps, the 
hygrometer (an instrument used to denote the quan¬ 
tity of moisture in the air, and with which every or¬ 
chid-house ought to be furnished,) will show that the 
air* is deficient of that humidity necessary for the 
strong, free growth of the plants. The operator then 
will resort to other means to effect this indispensible 
object. Those ordinary means are such as we have 
just mentioned—namely, wetting thoroughly, in the 
spring and summer, the walls, pipes, flues, and paths, 
with water, and this not only once, but twice, or even 
thrice, in hot weather, every day. By diligent use of 
such copious supplies of water, partly with the 
syringe, and partly with the watering pot, the air of 
the house will frequently, after being shut up, be so 
filled with moisture as to reach the saturation point, 
and will then deposit the watery particles upon the 
plants, in the shape of dew. This state of the air is 
what the plants delight in ; and if diligently perse¬ 
vered in—every other point of culture being attended 
to—every day from February to the end of August, 
the result will be—healthy, well-grown plants, ready 
to go to rest full of flower-sap, to form buds that will 
produce abundance of bloom the following season. 
This moisture in the air must be continued, to a cer¬ 
tain extent, all through the year. The air of the 
orchid-house ought never to smell, or feel dry. The 
experienced cultivator, on entering his house, will 
directly feel whether the air is in a right state or not, 
without looking at the hygrometer, just as he will 
feel whether the heat in it is too much or too little, 
and will immediately use such means as he knows 
will set all matters right, to give his favourite plants 
such an atmosphere as will keep them in good 
health. 
In autumn and winter, it will be sufficient to wet 
the paths, &c., every morning in dull weather; and 
in the evening, when tbe sun has been shining all 
the day. 
All this application of water, for the especial pur¬ 
pose of moistening the air, must be understood to be 
independent of the water applied by the syringe to 
water the blocks and the baskets, though, of course, 
that will be an additional help, materially assisting 
for the same purpose. These two points of culture 
may very properly be combined; that is, the syring¬ 
ing the blocks, and wetting the other parts of the 
houses, and then the air will be better moistened. 
There is yet another way of giving vapour to the 
air, that we have not alluded to—namely, with steam; 
and we can assure our readers it is a most effectual 
one. The reason why we have not described it 
before is, because it requires a considerable outlay, 
and more room than our amateur friends, perhaps, 
would like to incur. But as it is quite possible there 
may be some growers to whom these difficulties 
would not apply, we shall now give its history and 
application. 
About seven or eight years ago, we had the charge 
of the tine collection of Orchidaceae belonging to 
T. Brockleliurst, Esq., at the Fence, near Maccles¬ 
field. That gentleman spared no expense in any¬ 
thing likely to bring his collection to tbe highest 
point of perfection. Among other tilings, we had a 
small boiler set up for the express purpose of gene¬ 
rating steam to moisten the air of the houses, and 
it answered admirably. The boiler was of the com¬ 
monest description, of what is denominated the sad¬ 
dle-shape (a form that we consider an excellent one). 
From this boiler, which was placed in a shed behind 
the houses, an iron main-pipe was carried through 
the wall, round the front and back of the three 
houses. At intervals of 6 or 7 feet, holes were bored 
into the main-pipe; from these holes the steam 
rushed up among the plants too strongly, though at 
h feet distance. To correct this, we had small pipes, 
about 6 inches high, screwed into the holes. At the 
top of these pipes others, about 6 inches long, were 
