10 BULLETIN 1022, U. S. DEPARTMENT OF AGRICULTURE. 
values as affecting canning operations is therefore important for 
the present work; and while it is not possible to calculate by 
formulas the actual results which will be obtained in practice, be-. 
cause of other variable factors, the theoretical pressures and vacuums 
falling within the range of the present experiments serve as a back- 
eo 
anne 
Ce eel 
Le 
9! 
pals 7 
waruP ate a 
Param 
PRESSURE IN POUNDS PER SQUARE INCH 
pie 
A 
Vie ee 
Bie ae ard 
Tabak Moke te 
Sapeone 
PRESSURE IN POUNDS PER SQUARE INCH 
O 
fe, 
TIME IN MINUTES 
1g. 4.—Experimental time-pres- 
sure curves for No. 2 cans 
containing 550 ¢. c. of dis- 
tilled water sealed at uni- 
form. temperatures and proc- 
essed for 1 hour. Curve for 
can- =sealed® As At 207 Ce: 
and processed at 100° C.; 
a, at 20° C. and processed at 
116°C. 5. a, Fath 202 SC} and 
processed at 121° C.; B, at 
0 3} 0 Ap 6 
SEALING TEMPERATURE IN DEGREES CENTIGRADE 
Fie. 3.—Theoretical maximum-pressure 
curves for a nonexpansible can con- 
taining air and sufficient water to give ~ 
saturation, when sealed at different 
uniform temperatures and processed in 
the retort at 100°, 109°, 116°, and 
121° C. Calculations are made on the 
basis of mean barometric pressure. 
Curve for can processed: A, At 100° 
CAS 2B, soled OCMC eNO rete tale 
ab Api ©: 
CHD; 
70° C. and processed at 100° 
C.; 0, at 70° €. and’ proc- 
essed at 11162 (C3 04.26) 402 
Cc. and processed at 121° C.; 
C, at 80° C. and processed 
at 100°) Ca:46, at S8027€-4and 
processed at 116° €.3 c’, at 
80° C. and processed at 121° 
G 
ground for the work and as a guide in the interpretation of the 
experimental results. 
Theoretical pressure curves. —In figure 8 are shown the theo- 
retical maximum-pressure curves for a nonexpansible can contain- 
ing air and a sufficient quantity of water to give saturation, when 
