3-12 
AMERICAN AGRICULTURIST. 
[September, 
better than a good liot-waler apparatus. 
The objection ordinarily urged against the 
brick flues, is the escape of the gases evolved by 
the combustion of the fuel through the pores of 
the bricks, and more especially through the 
joints, these gases being very detrimental to the 
health of the plants. With care in the construc¬ 
tion of the flue, the escape through the joints can 
be almost altogether obviated, and if the draft is 
as it should be, no difficulty need be experienced 
from the escape of gases through the pores of 
the bricks. When any sort of cast-iron stoves 
is used, the objection generally made is the 
dryness of the atmosphere, superinduced by the 
hot iron, but this objection is founded upon a 
popular error. The dryness of the atmosphere 
is incidental to the winter season, as the moist¬ 
ure is all precipitated by congelation, and what 
moisture is artificially produced in the green¬ 
house is precipitated on the glass roof in the 
form of rime or hoar-frost, and this dryness 
will exist, if not counteracted artificially, under 
any mode of heating that may be adopted. 
Where the fire-pot of the stove is simply cast 
iron, injurious effects may result if it is allowed 
to become red-hot, but this is owing to the ac¬ 
tion of great heat upon the metal which ap¬ 
pears to cause it to give out deleterious gases. 
What these gases are, has eluded the observation 
of investigators, as air passed over red-hot iron 
plates fails to show the presence of any special¬ 
ly deleterious gases, but yet is sufficiently deadly 
in its character to kill a cat in a few minutes, 
when inclosed in a receiver of such an atmo¬ 
sphere. This can be obviated by having the 
fire-pot lined with fire-brick or soapstone. 
Another objection to stoves is that they are 
Fig. 1. —VERTICAL SECTION OF FURNACE AND FLUE. 
either too hot or too cold, not giving out the 
heat regularly; but the invention of base-burn¬ 
ing stoves has done away with this, as they are 
so constructed as to keep up an equable temper¬ 
ature when due attention is paid to the regula¬ 
tion and adjustment of the dampers. 
The pipes, however, rapidly rust away, unless 
they are made of galvanized iron, especially 
those carried under the shelving of the front 
platform. The use of sheet-iron pipes has one 
great advantage in the rapidity with which they 
respond to the action of the fire and heat the 
house quickly ; a matter of great importance in 
our climate, as it frequently happens that after 
a warm rainy day and evening in winter, when 
scarcely any fire is needed, the weather will 
suddenly clear up with high, cold winds from 
the westward, and before the fire can be got 
properly under way the temperature of the 
house will be so greatly reduced as to almost 
baffle all attempts to get it up to the proper 
point again before sunrise. 
It is often urged in favor of the use of hot- l 
water pipes that they give out a moist heat. A 
moment’s consideration will show the fallacy of 
this notion. The boilers are air and water tight, 
as are also the iron pipes themselves, and no 
vapor or moisture can escape from them except 
from the receiver, an iron column of perhaps 
six, eight, or ten inches in diameter, the evapor¬ 
ation from which would not exceed two inches 
in twenty-four hours. The great advantages in 
Fjg. 2. —HORIZONTAL SECTION OF FURNACE AND 
FLUE. 
the use of a hot-water heating apparatus are 
the equable distribution of the heat throughout 
the house, making the temperature almost the 
same at one end as at the other, and the slow¬ 
ness with which the water gives out the heat it 
has taken up from the fire, thus insuring an 
evenness of temperature during the whole night 
Its disadvantages are its cost in the first instance, 
and the slowness with which it responds to the 
action of the fire. The latter can be obviated by 
adding to it sheet-iron pipes or flues for the car¬ 
rying off the gases of combustion from the fire, 
an arrangement which in our climate should 
never be neglected, as a great saving of fuel re¬ 
sults from it. This, however, is seldom done, 
as the arrangement and setting up of such ap¬ 
paratus is almost always intrusted to architects 
or mechanics who generally know little about 
the cultivation of plants. 
In heating by brick flues the main point to be 
attended to is the construction of the furnace, 
which, for a greenhouse such as is described in 
our last number, should be 13 inches wide, 12 
inches high, and two feet deep. These dimen¬ 
sions are somewhat larger than those usually 
employed, but we prefer, from long experience, 
to have plenty of room in the furnace, as the 
combustion of the fuel is more perfect, and 
when required is more rapid, as it gives an op¬ 
portunity to use a thin, quick fire when necessi¬ 
ty calls for it. The ash-pit should be of the 
same hight, if practicable, but it may be reduced 
to eight or nine inches in hight, if necessary. 
Both the ash-pit and furnace should be provided 
with cast-iron doors, both hung on one cast-iron 
frame, if they can be had made in this way; 
otherwise each door may have its own separate 
frame. Thefframe should be anchored into the 
brick-work. The furnace bars should be 24 
inches long, one inch thick, and one inch wide 
at each end, three eighths of an inch thick in 
the body, and two inches deep in the center. 
They rest at each end on a cast-iron bearer, 
15 inches long, and an inch square. 
The furnace should be lined with fire brick 
laid fiat, and backed up on the two sides and 
back and on top with eight or twelve inches 
of common brick. The top of the furnace 
should be laid with a lliree-inch fire tile, 12 x 15 
inches. The flue starts from the top of the fur¬ 
nace; it is laid under the front shelf, on a foun¬ 
dation of brick, one brick thick, on the flat, and 
14 or 15 inches wide; the sides are built up of 
three bricks on edge, the clear space between 
them being 7 inches, making the area 7 x 12, 
if tiles are used for the covering ; but, if bricks 
are used for covering, the width must be re¬ 
duced one or two inches. It is common to 
make the tiles with a rabbet on each end and to 
lay them with the rabbets overlapping each 
other, but as it is almost impossible to make 
them smoke-light when thus laid, we always 
turn each alternate tile on its back and butt the 
edges of the rabbets together, which thus makes 
a groove or gutter half an inch deep and an 
inch wide, to be filled with mortar, and it is 
then perfectly tight. 
In laying the tiles or bricks as covering, we 
do not generally lay them so as to cover the 
full width of the sides, but regulate the width 
of the flue in such a way as to have the cover¬ 
ing (either bricks or tiles) short of the outside 
width of the flue, two or three iuclies, and lay 
the mortar on the edges in such a way as to 
make the flue appear as though its upper edges 
were chamfered. If the flue has to be carried 
under a doorway, it will be necessary to sink 
the furnace so far as to keep the bottom of the 
flue at its lowest part level with the top of the 
furnace; if it is carried lower than this, it will 
not draw. The bricks both for the furnace and 
flue should be damp when laid, and the mortar 
rather thin. Great care must be taken to lay all 
solid; every joint should be filled when laid, 
and so as not to require any “pointing up” 
afterwards, neither should the flue be “ parged ” 
or plastered on the inside, as ft soon drops off 
Fig. 3. —GRATE-BAR—SIDE VIEW. 
and chokes the passage. If the flue is not car¬ 
ried into one of the chimneys of the house, it 
should be taken through the side of the green- 
Fig. 4. —GRATE-BAR—TOP VIEW. 
house and a separate chimney made for it. If 
there should be any danger of a bad draft when 
the chimney is carried up near the dwelling, the 
flue may be returned alongside of itself to a 
properly safe point, and then carried out. 
If the greenhouse is to be heated by a base¬ 
burning stove, the stove-pipes should be five or 
six inches in diameter and made of galvanized 
iron. They may be suspended under the front 
shelves; but neither they nor the brick flue 
should come witliiu 8 or 9 inches of any wood¬ 
work, for fear of fire. 
A hot-water apparatus can only be set up by 
mechanics who are fully acquainted with Ike 
principles upon which 
it operates, and who 
have the mechauical 
skill necessary to put 
it together. There are 
several kinds of boil¬ 
ers in use, and if any 
of our readers should 
desire to heat their 
greenhouse by this 
method, we advise 
them to apply to some 
one of those who make it a specialty; their 
advertisements are to be found in almost 
any horticultural journal. For an ordinary 
greenhouse, especially if of small size, a brick 
flue or base-burning stove will answer every 
purpose, at less than one half what a hot-water 
apparatus would cost. Under any arrangement 
that may be adopted the fire end of the mode 
employed should be at the coldest side of the 
house when it can conveniently be placed there. 
