24 



BULLETIN 1141, U. S. DEPARTMENT OF AGRICULTURE. 



and slicer are driven by belts from a short countershaft placed above 

 the inlet end of the bleacher and driven by a belt from the main 

 drive shaft on the first floor. The machine should be raised suffi- 

 ciently above the floor to permit a broad- wheeled hand truck, carry- 

 ing a box 12 or 15 inches deep and having one side hinged so as to 

 drop down, to be placed directly beneath '.the. chute, down which the 

 slices pass. When the box becomes filled the truck is replaced by 

 another, and the loaded truck is rolled into the kiln, the side, dropped, 

 and the contents spread upon the kiln floor. The lowered side of the 

 box forms an incline down which the fruit runs without injury, 

 which is an advantage, as the freshly sliced rings are easily broken, 

 and unnecessary or rough handling at this time lowers the grade of 

 the fruit by increasing the percentage of broken pieces. The loading 

 of the kiln floor is begun at the corner farthest from the door, each 

 truck load being spread as uniformly as possible to a depth of 5 or 6 

 inches bv means of a broad-bladed wooden shovel and a wooden rake. 



Fig. 10. — An. apple bleacher. 



In this arrangement of equipment the fruit passes rapidly through 

 the various stages of preparation, a given apple reaching the bleacher 

 within l| to 2 minutes after it is placed upon the paring machine, thus 

 eliminating the discoloration resulting from standing in the air. All 

 transfers of the bulky material from floor to floor or about the build- 

 ing are accomplished by automatic power conveyors or by gravity, 

 the hand labor involved being reduced to the actual operations of 

 feeding peeling machines, trimming, and spreading the sliced fruit 

 on the kiln floor. This work does not require great physical strength 

 and is almost universally performed by women and girls. 



THE PRUNE TUNNEL EVAPORATOR. 



The term "tunnel evaporator," or "prune tunnel," as employed 

 throughout the Pacific Northwest, designates a drying apparatus of 

 a definite type, universally employed in the prune-growing districts 

 of Oregon, Washington, and Idaho for the curing of that fruit. As 

 it exists to-day it is the sole survivor from the early years of the 

 prune industry of at least a score of devices for drying prunes, most of 

 which were patented, as was the earliest form of the tunnel drier. It 



