20 CIECULAR NO. 131, BUREAU OF PLANT INDUSTRY. 



down, the area of the cross section would simply be the width multi- 

 plied by the height. If the rick were triangular in cross section, so 

 that the sides represented straight lines from the top of the rick to 

 the bottom on each side, the area of the cross section would be one- 

 half of the product of the base and the height. The actual area of 

 the cross section lies somewhere between these two. 



It is difficult to measure accurately the height of a rick. It is much 

 easier to measure the "over," which is the distance from the ground 

 on one side of the rick over the top of the rick to the ground on the 

 other side. The length of the over depends upon throe things: 

 (1) Width, (2) height, and (3) "fullness" of the rick. The over is 

 always somewhat more than twice the height. 



It has been found by actual measurement that the cross section 

 of a rick is the product of the over and the width, multiplied by a 

 fraction varying from 0.25 to 0.37 (average value, 0.31), depending 

 upon the height and fuUness of the rick. If the rick is low in com- 

 parison with its width and nearly triangular in outline — that is, its 

 sides are not very full — the fraction is small (0.25). If the rick is 

 taU in comparison with its width, and the sides are very full, so that 

 the top is well rounded, the fraction is large (0.37). Representing 

 this fraction by F, the over by 0, the width by W, and the length 

 of the rick by L, the volume being represented by V, we have the 

 following formula for determining the number of cubic feet in a rick: 



V=FOWL. 



The fact that the right-hftnd member of this formula spells the 

 word ''fowl" makes it easy to remember. 



Figure 1 shows the cross sections of hayricks of nine different 

 shapes, the corresponding value of the fraction F for each of these 

 shapes being inserted in the outline of each cross section. The 

 height of ricks Nos. 1, 4, and 7 (upper row) is three-fourths the 

 width. The height of ricks Nos. 2, 5, and 8 (middle row) is equal 

 to the width, while the height of ricks Nos. 3, 6, and 9 (lower row) 

 is one and one-fourth times the width. Ricks Nos. 1, 2, and 3 

 (left column) are narrow or nearly triangular in outline; ricks 

 Nos. 4, 5, and 6 (middle column) are medium fuU, while ricks Nos. 

 7, 8, and 9 (right column) are full and rounded. It will be noticed 

 that the value of Fis the same (0.31) in Nos. 3, 5, and 7; in Nos. 2 

 and 4 it is 0.28; and in Nos. 6 and 8, 0.34. 



In attempting to find the volume of hayricks the choice between 

 these various values of F may be found by comparing the shape of 

 the end of the rick — that is, the cross section of the rick — with ricks 

 Nos. 1 to 9 in figure 1. If the shape of the rick to be measured is 

 intermediate between those shown in figure 1, intermediate values 



{Cir. 131] 



