462 CALIFORNIA FRUITS: HOW TO GROW THEM 



and 26, 1909, he gave his conclusions on the desirability of machine 

 evaporation and a design for the construction of an evaporator which 

 embodied all his best work in this line. The accompanying drawings 

 and description are from Mr. Parson's writings : 



A fruit drying chamber capable of holding about two tons is about as large 

 as one heater can well handle. Wire trays two feet wide by five feet long are 

 as large as one strong man can conveniently handle; he might prefer them 

 shorter ; in fact, if the smaller tray would give a drier of sufficient capacity to 

 to meet the demands of the owner, he could make the trays two by four feet, 

 with a narrower furnace, to correspond. Where two men are always available, 

 trays three by six feet have been found to work well. 



A drier five feet wide and twenty-four feet long, having ten trays in its length 

 and twelve trays high, holds 120 trays 2 by 5 feet, or a total drying surface of 

 1,200 square feet, which at the rate of 3 pounds per foot give a total of 3,600 

 pounds at one time : that is, it would take that much gross weight of fruit before 

 cutting to fill the trays. Large fruit would amount to more, and. small fruit or 

 culls might not go above two pounds to the foot. 



By making the drier one or two trays longer and higher, and a foot or so 

 wider, the capacity may be materially increased. But if much more capacity is 

 desired, it would be better to build another drier, or several of them, alongside of 

 it, which would work satisfactorily. 



The fruit drying chamber rests on top of the hot air chamber, which is 

 surrounded by brick or cement walls about eight inches thick, and is as long and 

 wide as the fruit chamber above. The height of these walls depends on the size 

 and shape of the heater enclosed by them. The furnace is a very important 

 factor: it must be strong, not easily burned out, smoke-tight in all its joints and 

 flues, with caps or covers so placed to facilitate cleaning out soot and ashes. 

 There must be room between the sides of the furnace and the side walls to allow 

 for circulation of the air to be heated. 



Fresh air enters this hot air chamber through openings about a foot square 

 at the bottom in front between the furnace and the side walls; passes along on 

 the sides and top of furnace and flues until it reaches the back end of the hot 

 air chamber, where it passes up through an opening into the fruit chamber above, 



The next, and perhaps the most critical, part in the construction, is the sheet 

 iron floor which covers the furnace and flues and separates them from the fruit 

 chamber above. This iron floor is made of either black or galvanized iron, not 

 thinner than No. 24; thicker would be better. It rests on rods or bars of angle 

 or T iron stretched from wall to wall, with ends built into the walls. These 

 rods are spaced about two feet apart. The sheets of iron should be riveted or 

 bolted together. The edges of this iron floor should project into and be imbedded in 

 the brick walls in front and along the two side walls as far back as the floor 

 goes to the other end of the drier. Cover this floor with an inch or so of sand 

 or fine earth, so as to stop up all cracks. At the back end of drier this iron floor 

 is cut short one foot, allowing an opening of one by about five feet to allow the 

 hot air from the heater below the iron floor to pass up into the fruit chamber 

 above. This floor must be made tight everywhere, so no hot air can possibly 

 leak upward and scorch the fruit or the woodwork above. 



The brick walls should be built about eighteen inches above the iron floor, so 

 that the wooden frame which rests on top will be safe from burning. 



The furnace may be about four feet high by three feet wide, with an ash 

 pit in the bottom part, and six or eight or more feet long. This will handle 

 four-foot cordwood conveniently and make a liberal combustion chamber for the 

 flames. It may be a cylinder or shaped like a boiler, or have brick walls, with a 

 cast iron arch on top. Or it may be a big wrought iron box made of quarter-inch 

 boiler iron, braced with angle iron to prevent warping. 



A smoke pipe one foot in diameter connects with the back end of the furnace, 

 passes horizontally to near the back end of the drier, then by a short elbow 

 doubles back, coming to the front over the top of the furnace, and then, by an 

 elbow, to right or left through the side brick wall to connect with the pipe inside 

 of the ventilator shaft or flue. 



