148 THE BELL SYSTEM TECHNICAL JOURNAL, JANUARY 1953 



treating solutions for Charges 19-21 and 71-76, inclusive, are shown in 

 Table III. The relation of the density of the blocks to the pickup, i.e., the 

 absorption at time of treatment, is illustrated in Tables IV, V and VI and 

 in Fig. 6. The data have been split up to facilitate reference. 



Table IV shows the complete data for oven dry density and for ab- 

 sorption in grams per cc of block volume for Charges 19, 20 and 21, with 

 values for the average, for the standard deviation, and for the coefficient 

 of variabiUty. The pickup varies inversely as the density, which is to be 

 expected when random blocks instead of selected density blocks are 

 employed. The coefficient of variability in the density figures is evidently 

 greater than it is in the pickup figures; and a lower figure for the latter 

 is related to a lower figure for the former. 



0.62 



0.61 



0.60 



til 



I 0.59 



-I 

 O 

 > 0.58 



:«: 

 o 



3 0.57 

 CD 



fe 0.56 



0.55 

 0.54 

 0.53 

 0.52 

 0.51 

 0.50 

 049 

 0A& 

 0.47 

 0A6 



0.45 



0.44 



0.720 



0/400 0.440 0.460 0.520 0,560 0.600 0.640 0.68 



DENSITY (OVEN-DRY BASIS) 



Fig. 6 — Regression lines for absorption at treatment, in gms/cc of oven-dry 

 block volume, on oven-dry density of the %-inch cube test blocks. 



