142 FUMIGATION METHODS 
and practically the same results obtained. In any 
event, it is only necessary to get an accurate outline 
drawing of the section of the house, and by projecting 
this over squares as indicated the number of square feet 
in the section can be readily determined. 
The cubic contents of the two styles of greenhouses 
shown in Fig. 73 are easily estimated, according to the 
following scheme by Professors Woods and Dorsett. 
At the left is an even span house 1oo feet long, 12 feet 
wide, 2 feet on the sides, and 5 feet 6 inches from the 
FIG. 73—EVEN AND THREE-QUARTER SPACE HOUSES AT LEF! 
AND RIGHT—END SECTIONS. (AFTER WOODS AND DORSETT) 
the surface of the beds to the ridge, with a walk 14 
inches wide and 15 inches deep. To determine accu- 
rately the number of cubic feet in a house make a 
rough drawing showing a cross-section, and divide the 
space into triangles and rectangles by drawing a line 
connecting the two wall plates and one from the ridge 
at right angles to this; mark on each its respective 
length in feet and inches. Compute the number of 
cubic feet in each of the rectangles and triangles. In 
the even span house, shown at the left, the number of 
cubic feet of space in the walk is found by multiplying 
the width by the depth by the length, thus: Multiply 
