November, 1916 
THE GARDEN IM A G A Z I N E 
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The greenhouse range, considered as part of the garden scheme, can be planned in relation to the whole and so becomes an integral part of the picture 
they keep their shape. Wooden houses soon 
show sags and bulges, and inside wood soon 
discolors. The semi-iron house is simply a 
step between the all-wood frame house and 
the all-iron frame house. 
INTERIOR DETAILS 
In three-quarter-span houses and leantos, 
the benches can be stepped up; in fact, they 
should be so as to equalize the light. In even- 
span houses (regardless of compass points), 
the benches should be kept to one level, that 
of the sill, for if dropped below this point the 
plants will “draw” considerably. 
Bench construction has kept pace with 
other details of greenhouse construction. The 
bench de luxe, is one with galvanized iron 
frame, porous tile bottoms, and slate sides. 
'I bis will last as long as the greenhouse and 
always be neat in appearance. There are 
several other types of bench. One is con- 
structed entirely of concrete and will give 
good service though .some growers complain 
somewhat of the bench not drying out as it 
should. There is an all-metal bench with 
perforated bottom which is serviceable. Still 
another type is to use a galvanized iron frame 
with either porous tile or wood bottom, and 
wood sides. Of course, all wood used for 
bench construction should be “ pecky ” cypress; 
no other wood is worth putting in. An all- 
wood bencii is hardly worth considering be- 
cause of sagging, and repairs are usually very 
unsightly. Growing benches are usually con- 
structed with six-inch sides. Plant tables for 
potted plants have one-inch sides. In this 
case the best bench is one with galvanized iron 
frame and planed slate bottom, and indeed, 
this is the customary equipment for palm and 
plant houses. 
The outside bench of a greenhouse should 
be kept a few inches away from the outer wall. 
This is not, as some people think, waste space; 
it is the proper point for the heat to arise from 
the coils, tempering the cool air at that point 
and of course following the glass line up the 
roof. 
The arrangement of the benches depends 
altogether on the width of the greenhouse. 
The side benches should not exceed three feet 
in width as that is as far as a person can reach 
to work on the bench. Centre benches that 
have walks on both sides can be made as wide 
as six feet. A house eleven feet wide gives 
two side benches; one eighteen feet gives two 
side benches, and one wide centre bench; a 
twenty-five foot wide house gives two side 
benches and two wide centre benches. 1 hese 
are the most popular widths of standard green- 
houses, giving adecjuate bench space and pro- 
per roof pitch. 
GETTING AIR INSIDE 
The ventilation of a greenhouse demands 
careful study. Every greenhouse, no matter 
how small, should by rights have double 
ridge ventilation — that is, continuous ven- 
tilating sash on both sides of the ridge. This 
allows the operator to ventilate on the leeward 
side, thus avoiding draughts, dhe apparatus 
that controls the ventilator should be brought 
down to a convenient place for the operator 
and should be of the self-locking type. 
Side ventilation of some kind is necessary. 
There are two distinct systems. One is to 
have continuous ventilating sash above the sill 
which of course is above the benches. The 
other is panels in the foundation walls which 
admit the air under the benches. Advocates 
of the former system claim that the latter 
method does not admit enough air to insure 
proper ventilation during spring and summer; 
advocates of the latter method claim that the 
vents above the benches are likely to cause 
mildew and other trouble from cold draughts, 
that the inside of the house is cluttered up 
with a lot of needless ventilating apparatus, 
and the sides of the house above the benches 
must have a lot of fittings which are, of course, 
shading members and that roof shading is the 
only proper method of reducing the tempera- 
ture in the greenhouse during warm weather. 
GLASS AND GLAZING 
There is just as much difference in the 
quality of glass as there is in anything. 
Greenhouse glass should be white; the dense 
green glass is very objectionable as it reduces 
the light considerably. Flaws of every ki.nd 
must be eliminated; they cause foliage burns 
of all kinds. Ordinary single weight glass 
weighing eleven ounces to a square foot 
can be used when the glass does not exceed 
twelve Inches in width, but hail will cause 
considerable breakage. Twenty-two ounce 
glass, which is “double thick,” should be used 
for all spans greater than twelve inches, and 
it is not uncommon to see twenty-nine ounce 
or thirty-two ounce glass used nowadays in 
modern greenhouse construction. Naturally 
the larger sheets make a heavier glass more 
desirable. 
Ground glass should be used on plant 
houses where Palms and other e.xotics are 
