GREENHOUSE AND COLD FRAME FUMIGATION 143 
1 foot 2 inches by 1 foot 3 inches by 100 feet ; redu- 
cing to inches, we have 14 inches multipled by 15 inches 
by 1,200 inches equals 252,000 cubic inches; dividing 
this result by 1,728, the number of cubic inches con- 
tained in a cubic foot, we have 145.83 cubic feet. The 
rectangle 4 D G Fis computed in the same way, ex- 
cept that in this case it is not necessary to reduce the 
feet to inches. It would be 12 feet multiplied by 2 
feet by 100 feet equals 2,400 cubic feet. 
The rule generally given for calculating the area of 
a right-angle triangle is to multiply the base by the 
perpendicular and divide the product by 2. The result 
multiplied by the length of the house will give the 
number of cubic feet the triangular portion contains. 
For example, taking the triangle 4 C E: 6 feet mul- 
tiplied by 3.5 feet equals 21 feet, divided by 2 equals 
10.5 feet, multiplied by 100 feet equals 1,050 cubic 
feet. The area of the triangle & C D and the cubic 
feet in this part of the house are determined in the 
same way; or, in this case, since the triangles are 
equal, the desired result is obtained by multiplying the 
number of cubic feet in the triangle 4d C E by 2; 
1,050 multiplied by 2 equals 2,100 cubic feet. The 
contents of this house is therefore 145.83 plus 2,400 
plus 2,100 equals 4,645.83 cubic feet; this result 
multiplied by the required dose per cubic foot of space 
will give the amount of cyanide of potassium necessary 
for one fumigation. 
At the right, in Fig. 73, is a cross-section of a three- 
quarter span house 100 feet long, 18 feet wide, front 
wall 4 feet 4 inches, back wall 6 feet 4 inches, and 1 
feet 10 inches to the ridge. The cubic contents of this 
