GROUND-WOOD PULP. 93 
steamed at varying pressures for periods of three and six hours and 
then ground in two pockets of the grinder at a cylinder pressure of 
60 pounds per square inch. The power to the grinder was main- 
tained at 345 horsepower, and it was utilized by adjusting the periph- 
‘genio ar fe: ee Ala 
A i oh Was 
(1) Spruce runs 9-1 to 11 and (2) 6 to 8, inclusive. 
0 
HORSEPOWER PER TON—BONE DRY 
SSS ibm Se ate en ae 
ASEN@ | Age 
STRENGTH FACTOR— POINTS PER LB. 
Fig. 13.—Relation of strength of paper and power consumption to pressure. 
A 
“NUS Uad°S81—U3ZGNITAI‘NI VE NO 3UNSS3ud 
eral speed of the stone to such a value as was necessary for the sample 
being tested. When wood which had been steamed for 6 hours at 
75 pounds pressure was ground a cylinder pressure of 60 pounds on 
two pockets and speed of 225 revolutions per minute were necessary 
