124 CHEESE MAKING. 
239. Number and Size of Tiles. 
The first ducts constructed were single tubes, but they were 
too near the surface and therefore unsuccessful. The first suc- 
cessful duct was made by placing thirteen rows, one hundred 
feet long, of six-inch tiles eight to ten feet in the ground. These 
tiles were, however, somewhat small in diameter, and by fric- 
tion hindered the passage of air on still days when most needed. 
Professor King recommends not less than three ten-inch 
tiles one hundred feet long for a curing room of 5,000 cubic 
feet of space. Longer tubes and more of them twelve feet down 
would be better. 
240. Use of a Well. 
The illustration (Fig. 59) shows how a well may be used 
for cooling the air of a curing room. It is one of the most 
successful plans proposed for this purpose. 
241. Water Motor Fans for Driving Air. 
The weak point in the sub-earth duct is that there may be 
several days of hot weather with little wind when the cow! will 
not work. At such a time a fan driven by water motor will cir- 
culate the air. The Triumph Dairy Co., Triumph, Ohio, has 
such a contrivance. A five-barrel tank of water on top of the 
building will run the fan most of the night. The tank is filled 
with water by a steam pump. 
242. Boiler Room. 
The boiler room should have a cement floor laid on the 
ground, and the walls and ceiling should be lined with corru- 
gated sheet iron, to insure against fire. 
243. Building Should be Raised. 
The rest of the building should be raised about a foot above 
the ground, so that air-‘may circulate beneath and keep the sills 
from rotting. 
244. Water Supply. 
A good well is an absolute necessity for a cheese factory. 
Water can be pumped into a galvanized iron cistern placed 
above the curing room. This cistern should be set in a drip 
