PRODUCING SODA PULP FROM ASPEN". 



11 



to the charging temperature and run into the digester, and the cook- 

 ing operation was begun by permitting live steam to enter at the 

 bottom. 



During the cooking, observations were made at 15-minute intervals 

 of (1) digester temperature, (2) digester pressure, (.3) steam pressure 

 at digester inlet, and (4) room temperature. The volume of liquor 



in the digester was also observed, but at hourly intervals. These 

 observations were recorded, and a graphic "log of cook" was made 

 at the same time, an example of which is shown in figure 3. If at 

 any time the digester temperatures and pressures as observed on the 

 thermometer and pressure gauge did not agree when compared by 

 means of pressure-temperature tables for saturated steam, the excess 

 of pressure was relieved ; such a condition occurred as a rule only dur- 



