36 MODERN FRUIT MARKETING 
Most of the mechanical graders work on practically 
the same principle. They have a series of cups or open- 
ings into which the apples are fed from the hopper. 
As these cups advance they gradually increase in size 
until the apple contained in them falls through. The 
cups are the smallest at the intake. As the fruit ad- 
vances, it falls through at different places, and is caught 
in receptacles or compartments according to the sizes 
Fig. 25.—A MECHANICAL GRADER HAVING A MOVEABLE WEB 
desired for packing. From these compartments it is 
packed into boxes or barrels as the case may be. There 
are several different types on the market, but these cups 
constitute the main principle. Some of them have long 
webs, and the cups pass around these webs like a belt. 
Others work in horizontal circles and still others are on 
a vertical wheel resembling somewhat the principle of 
the old-fashioned water-wheel. 
In Figure 26 is shown a method of grading. The 
sizing is accomplished by 28 wooden flights mounted on 
