New York AGricutturAL ExprrRIMENT STATION, O17 
trench may be dug narrower and one or two feet deeper and the 
tile placed one above the other. The shaft for carrying the 
funnel must be made tight; it may be 12 inches square,.if made 
of plank, or 12 inches in diameter, if made of galvanized iron. 
The height should be sufficient to enable the funnel to catch the 
wind readily. The construction and mounting of the funnel are 
illustrated in Plate IX. The extreme diameter of the funnel 
should be about 36 inches. 
The inlet from the sub-earth duct into the curing-room must 
be provided with some arrangement of valves that will permit 
the air to be shut off wholly or partly. Too rapid entrance of 
air in warm weather.will not permit enough cooling during pas- 
sage through the duct. In case of dry winds, too rapid entrance 
would reduce the moisture too much. 
In Plate X there is illustrated a deep vertical sub-earth duct. 
Such a duct has the advantage of requiring less piping and also 
less wind will suffice to produce a current of air. The vertical 
duct should have a depth of not less than twenty-five or thirty 
feet, provided water is far enough from the surface. Thirteen 
lines of 6-inch drain or 5-inch galvanized iron conductor pipe 
may be used and placed as in the cut. The duct should be 
located near the north end of the curing-room or directly 
beneath it. A hanging platform can be used in placing the 
pipes or tubes in position and the earth packed carefully around 
the pipes. An excavation of proper size, made as for an 
ordinary well, will answer the purpose. After the duct has 
been placed in position the earth that has been removed can be 
used for filling around the duct. 
In Plate XI there is represented a duct connected with a well 
of water. In the particular instance illustrated, the well is 64 
feet deep; the intake pipe is 10 inches in diameter, rising just 
barely above the roof of the factory, entering the well, as shown 
at A, two feet below the surface of the ground and then descend- 
ing inside the well a distance of 8 feet. Another 10-inch gal- 
vanized iron pipe starts 40 feet below the surface of the ground 
and rises to within 5 feet of it, when it turns and passes hori- 
