682 Journal of Agriculfiire. Victoria. [10 Nov., 1917. 



The Furnace. 



The statements made in the section devoted to heating apparatus for 

 kilns holds true here. The only economical and durable heating equip- 

 ment is a well-built brick or stone furnace, lined with firebrick, of suffi- 

 cient height and depth to take ordinary cordwood without preliminary 

 splitting or cutting to shorter lengths. The ordinary hop stove, built 

 as it is of thin sheets of cast-iron, will not stand up imder the continuous 

 heavy firing of a 50 or 60-day apple-drying season. 



If the tunnels are floored except for a distance of 2 to 4 feet at the 

 lower end, the furnace should stand immediately below this opening in 

 order that the heated air may pass directly upward into the lower end 

 of the tunnels. The fact that the furnace room is 2 feet longer than the 

 tunnels permits the furnace to stand in this position. The chimney 

 should be placed at one side of the building, the pipe rising from the 

 furnace should be fitted with a T joint, and the two lines of pipe carried 

 around the walls of the room before they are connected with the flue, a_s 

 described in the section on piping of kiln furnaces, page 24. If the 

 floors are of sheet-iron, the pipe may bo brought up to within 24-30 inches 

 of the floor and kept at that distance in its passage around the room ; if 

 the tunnels have board floors or no floors at all, it must be kept about 

 a foot lower to prevent overheating. The " single-pipe " system of 

 piping will give sufficient radiating surface, and the distance of the 

 pipes from the walls should not be less than 24 inches. The pipe 

 should be of the quality recommended for use with kiln furnaces, and 

 should be 9 inches in diameter. The chimney should be, at least, 12 x 

 12 inches inside, if only one furnace is piped into it, 12 x 18 if two 

 are connected with it. It should be solid up to within 18 inches of 

 the entrance of the pipes, and should extend 4 or 5 feet above the roof. 

 As free access to both ends of the tunnel is necessary, the chimney should 

 stand at the side of the building, with the pipe passing beneath the floor 

 to reach it. 



The Constelttion of Trats. 



Trays are best made from -J x 1^-in. slats. Cut two pieces 3 feet 

 and two pieces 4 feet long, nail these together to form a rectangular 

 frame 4x3 feet and l-i inches deep. Cut a piece of wire-netting 1 inch 

 larger each way than the frame, turn the edges back to give a firmer hold 

 for nailing, and nail the netting to tlie frame. Now cut a second set 

 of slats and nail these to the bottom of the tray, taking care that the wire 

 is not allowed to project. Lastly, nail a wooden strip across the middle 

 to prevent warping of the frame. This gives a reversible tray, which has 

 no projecting wires to tear clothing and hands or catch in the tunnels. 

 The bottom cannot become loose from the frame, and can be kept from 

 sagging by using the tray either side up. 



Trays should be made of the best grade of galvanized wire-screen 

 obtainable, with meshes -} or i inch square. An inferior, poorly-gal- 

 vanized wire will be attacked by the acid juices of the fruit with dis- 

 colouration and injury to the product. The German Government has 

 long made strenuous objection to the use by her people of apples dried on 

 wire trays, on the ground that sucli fruit may absorb sufficient quantities 

 of zinc to be injurious to consumers. WTiile this claim is not borne out 

 by the results of chemical analysis, it has resulted in laws prohibiting 

 the sale in Germany of apples containing more than a specified amount 



