1740 



ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 



appear to do equally efficient work, and 

 at no appreciable difference of cost. There 

 have "been some new styles placed upon 

 the market, but so far as I can learn 

 they are unsatisfactory. The majority of 

 our growers are satisfied with the types 

 in use for the past 15 years. 



The tunnel dryer consists of tunnels, 

 whose inside measurements range around 

 30 inches in width and four and a half 

 feet in height. In them are placed trays, 

 usually of galvanized woven wire spread 

 on a wooden frame. These trays are 

 placed either on cars or on rows of porce- 

 lain insulators attached to sides of tun- 

 nel. Nine trays are placed on a car, 

 spaces between the trays being wider at 

 the bottom and gradually decreasing to- 

 ward the top. About the same distance 

 between trays is observed when they are 

 placed on insulators. Tunnels vary in 

 length from 18 to 36 feet. The end 

 farthest from the furnace is made higher 

 than the other end. The difterence in 

 height of ends varies according to length 

 of tunnel and views of architect. My 

 36-foot tunnels had a difference of four 

 feet. The fruit is placed in the upper 

 end, and a car or tray of done fruit is 

 removed at the lower end. The greener 

 fruit advances toward the heat. 



The stack dryer consists of a stack of 

 trays placed one above the other to a 

 height convenient to be reached from the 

 operating floor. In the most uniform 

 styles of this type it is arranged so that 

 pressure of upper trays can be lifted 

 from the lower tray. The latter is then 

 withdrawn when its fruit is sufficiently 

 dried. The trays above are then mechan- 

 ically let down to take its place, leaving 

 room at the top for inserting a fresh 

 tray. Four tunnels or 16 stacks (eight 

 on each side) are considered about the 

 proper limit for one furnace. 



With all dryers there must be a lower 

 story for accommodation of the furnace 

 and pipes. For safety from fire a space 

 of at least eight feet should intervene 

 between the furnace and the floor of the 

 stack or tunnel. A side hill affords best 

 location for a dryer, as it allows room 

 for the lower story without having to 



build a platform driveway to reach the 

 main floor, A temperature of about 180 

 degrees, at the point where the heat 

 emerges from the furnace room into the 

 kiln, produces best results. Hop stoves 

 of specially durable construction, or 

 steam boilers fitted up for the purpose, 

 are more satisfactory than brick fur- 

 naces. It is very difficult to keep the lat- 

 ter in safe condition. The pipes are con- 

 fined to the furnace room and are de- 

 signed mainly to assist the furnace in 

 radiating heat. A large area of radiating 

 surface in the pipes is therefore desir- 

 able. Sixteen-inch pipe is a common size. 

 From three-fourths to a cord of fir wood 

 is consumed in turning out a ton of 

 dried prunes. Mr. A. C. Goodrich, of 

 Yamhill, Oregon, member of the Oregon 

 State Board of Horticulture, has recently 

 fitted out an apparatus for burning oil. 

 This rectuires no change in construction 

 of evaporator. He tells me that the oil 

 is cheaper than fir wood at $3.50 a cord, 

 and has the further advantage of making 

 it possible to maintain a uniform tem- 

 perature, regardless of weather condi- 

 tions. This cannot be done with wood 

 for fuel. 



Twenty-eight to 30 hours is the aver- 

 age time required for drying Italian 

 prunes, depending on ripeness and 

 weather conditions. Evaporation is 

 much more rapid on a clear, warm day 

 and in absence of wind. 



Apples require considerably less time 

 to dry than prunes. All prunes should 

 be dipped in boiling lye before being sub- 

 jected to the drying process. A dipping 

 vat containing boiling lye is provided. 

 Into this a wire basket holding about a 

 half bushel of fruit is immersed two or 

 three times and for only a few seconds. 

 The same basket is then dipped into va- 

 rious rinsing tubs of cold water and the 

 contents of the basket are then emptied 

 upon a tray to be spread. 



There are satisfactory appliances in 

 use by which the operations of dipping, 

 rinsing and spreading are accomplished 

 with a minimum of hand labor. The ob- 

 ject of dipping in the lye is simply to 

 facilitate evaporation by checking the 



