CHEESE MAKING 69 



To Prepare Table for Psychrometer Reading. 



See W. B. Bulletin No. 235, Department of Agri- 

 culture, Washington, D. C., or Smithsonian Physio- 

 logical tables, p. 155. 



Observe, 1, psy chrome ter reading; 2, dew point. 



From table referred to determine relative humidity 

 as follows: (from dew point reading): Example: 

 If dew point - 10 C. (50 F.) and temperature of 

 air = 30 C. (86 F.) the weight of saturated vapor 

 in air at 10 C = 9.33 grm. per c. m.; the weight of 

 saturated vapor in air at 30 = 30.04 grm. per c.m. 



(This table was made for the sling psychrometer 

 and does not exactly correspond to the one on the 

 opposite page.) 



Q *33 



Relative Humidity = - = 31.1% 

 o0.04 



Then prepare table : 



Dry Bulb Wet Bulb Rel. Hum. 



30C 18C 31.1C 



Moisture can be supplied by sprinkling the floor, 

 or better still, by hanging up wet sheets that are 

 constantly supplied with water. 



To supply a curing room of 5000 cubic feet capacity 

 at least 3 cloths 30 inches wide by 12 feet long are 

 needed. To keep them saturated with water hang 

 them on pipes with fine holes drilled on the upper 

 side, and a gutter below to carry off the surplus 

 drippings. When the cloth gets stiff from sediment, 

 boil it in water to which a little hydrochloric acid 

 has been added. 



