CONSTRUCTION AND OPERATION OF CHEESE Factrorigs. 123 
te right to use with a sub-earth duct, but double windows and 
doors should be put in to make the room perfectly tight. The 
illustrations here given of the construction of cheese curing 
rooms and of a ventilating duct are taken from Bulletin 70, of 
the Wisconsin Experiment Station, by the late Prof. F. H. King. 
7. 
Fig. 59.—Vertical section of a cheese factory and sub-earth duct in 
well at Colby, Wis. A, A, funnel taking air into well; B, B, B, duct leading 
air from well to curing room; C, D, ventilator. 
