46 THE CONSTRUCTION OF THE FORCING-HOUSE, 
the two upper benches, and another 3-inch flow and three 
1%-inch returns heat the lower bed. This same house 
could be heated with steam by one 2-inch riser and six to 
eight 1%-inch returns. An exposed tomato house (Fig. 
14, page 31), is heated by a 1%-inch steam riser which 
feeds a 1-inch loop running around the house just under 
the plate, and four 1%-inch loops just above the soil. 
Another loop and a half (from an independent riser) runs 
about the center walk. In this house, the bottom heat 
is supplied by the heaters themselves, which stand just 
beneath the floor. The floor is made of two layers of 
inch boards, with tar between the layers. 
Fig. 15 (page 32), showing a house used for lettuce, 
cauliflowers, carnations and chrysanthemums, 20 ft. wide 
and 60 ft. long, is heated by one 2-inch steam riser and 
two 1%-inch returns under each side bench. The middle 
bench is solid, and has no bottom heat. Fig. 28 (page 45) 
shows the water returns in a tomato house near Philadel- 
phia. There are eight returns under each bench, the coil 
standing edgewise under the left-hand bench, and lying 
flat-wise under the other. 
Flues and stoves.— Beginners with little capital can make 
a very good forcing-house with old sash, and can heat the 
same with flues from a home-made furnace. Lettuce houses 
can even be heated with a coal stove. The novice will 
always do well to begin with a small and simple establish- 
ment, although it rarely pays to erect a very cheap house 
if it can be avoided. 
COST OF FORCING-HOUSES. 
Only the most general remarks can be made respecting 
the cost of forcing-houses, for so much depends upon the 
finish, the expense put in foundations, and the experience 
and efficiency of the workmen. Taft estimates the expense 
of building a three-quarter span rose house, 20x Ioo ft., 
including heating apparatus, to average about $1,100 to 
