November, 1911 
Fig. 7—Dimensions of bars 
nected with the heating apparatus in the building to which 
it is attached. It should, when possible, face the south 
and, due to its peculiar construction, receives no reflected 
light whatever from the north. The plants grown in this 
type of house are, therefore, inclined to be more or less 
one-sided in their habit of growth. 
The lean-to is used for forcing various kinds of vegetables 
and for raising such cool crops as lettuce, violets, etc. 
THE EVEN-SPAN HOUSE 
The even-span house is the type most 
commonly used by florists. It can be 
built at a cost of $8.00 to $25.00 per 
running foot, depending on its width 
and the amount of labor figured in. 
As shown in Figure 2, it is a perfectly 
symmetrical house, the ridge being in 
the center of the roof span, the roof 
slopes being the same, and the sides 
being of the same height. It is an all- 
glass house and is constructed of 
widths varying from 8 to 42 feet. 
The width of the average commercial 
house is about 24 feet. This type of 
house usually faces the south—that is, its ridge runs east and 
west. Some florists consider that the light is more evenly 
distributed around the plants if the house faces the east, but 
the majority, however, prefer the southern exposure, for in 
this case, during the winter months, when the sun falls to- 
ward the southern horizon, the shade cast by the ridge and 
corners of the house is to a large extent eliminated. With 
either exposure the plants receive light from all directions, 
and this is, therefore, one of the types best adapted for 
general greenhouse work. 
The even-span house is used extensively for growing 
carnations, roses, violets, chrysanthemums, potted plants, 
and in fact all kinds of flowers and vegetables. 
THE THREE QUARTER-SPAN HOUSE 
The three quarter-span house, two thirds, or uneven-span, 
as it is sometimes called, is shown in Figure 3. ‘This type 
of house costs about the same as the even-span. It is de- 
signed for a more even distribution of light over the 
benches than it is possible to secure with the even-span and 
it differs from it in the construction.of the roof and the 
north wall, and frequently in the arrangement of the 
benches. The ridge, instead of being placed in the center 
of the roof span, as in the even-span house, is placed near 
enough to the north wall so that its shadow does not fall 
on the benches. The north wall is constructed two or three 
feet higher, in this type, than the south wall and is gen- 
erally built of wood or concrete up to within one or two 
feet of the eaves. The benches, in order to receive the 
maximum amount of light, are then arranged in tiers. 
AMERICAN HOMES AND GARDENS 
Fig. 8—Framework of timbers 
Fig. 10—Framing method 
407 
Vertical Sash Bar 
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ee 
Fig. 9—Details of framing 
This type of house, of course, must face the south, and, 
due to the fact that the plants receive the maximum 
amount of light evenly distributed, a structure of this sort 
is often spoken of as a “forcing house.” 
The two thirds-span house is especially adapted to 
the growing of roses, and is used most frequently for that 
purpose. It is, however, an excellent house for all kinds 
of plants and flowers such as the amateur usually begins with. 
SELECTION OF TYPE 
The individual requirements in each 
case will, of course, determine which 
of these three types should be selected. 
Unless extreme low cost is the prime 
consideration, the amateur should sel- 
dom select the lean-to, for the results 
obtained with the other types will more 
than justify their greater cost. 
Between the even-span and the two 
thirds-span house it is often difficult to 
choose. Due to the better distribu- 
tion of light in the latter, somewhat 
better results can be obtained than in 
the even-span, although the difference 
is slight. Since the even-span house is symmetrical, how- 
ever, the amount of labor involved in its construction is 
undoubtedly less than in the three quarter-span house. 
In selecting the type which he shall use, the amateur 
should take into consideration (1) the kinds of plants that 
are to be grown in the house, (2) the cost of the house, 
and (3) the amount of labor involved in its construction. 
LOCATION 
The house should be located on ground which is well 
drained and far enough from trees or buildings so that no 
shadows will be cast upon it. If it is located on low ground 
which receives the drainage from the surroundings, it will 
tee pct 
Soke ss 
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4 MELE 
-be continually damp, and the plants will be liable to have 
diseases. If possible, it should be so located that it will be 
more or less protected from the north and west winds. 
FOUNDATION. 
The foundation should be made of concrete. The prop- 
erties of concrete are so well known that it is hardly neces- 
sary to state why this is the most satisfactory and in the 
end the cheapest foundation. It should be at least six 
inches wide and, depending on the kind of soil in which 
it is located, from twelve to thirty inches deep. 
A good concrete will be obtained by mixing one part 
cement with two parts sand and given parts of gravel or 
broken stone. After the mixture is saturated with water, 
it should be placed in forms, built of seven eighths inch or 
one-inch boards, rammed, and allowed to set at least 24 
hours. Square-headed bolts, six or eight inches long, 
should be embedded about six feet apart in the concrete 
