SHRINKAGE OF CORN IN STORAGE. 5 



of the atmosphere and to general weatlier conditions. The results of 

 these records and observations are shown diagrammatically in figures 

 2 and 3. Figure 2 shows the shrinkage in the weight of the corn, the 

 average temperature of the corn, the average of the daily mean air 

 temperatures for the periods between weighings, the mean daily 

 relative humidity of the atmosphere, and the weather record from 

 Januar}' 5 to April 21, after which time the rate of deterioration in tlie 

 corn was such that the relative humidity of the atmosphere and the 

 general weather conditions exerted no apparent influence on the 

 amount of shrinkage. Figure 3 shows only the shrinkage in the 

 weight of the corn, the average temperature of the corn as indicated by 

 the four electrical-resistance thermometers at the time the weighings 

 were made, and the average of the daily mean air temperatures for 

 the ])eriods between the dates of the weighings from the beginning of 

 the experiment, January 5, until June 1, at which time the test was 

 terminated. 



Immediately after the corn was placed in the hopper of the scale 

 the average temperature of the corn, as indicated by the four electrical- 

 resistance thermometers, the positions of which are shown in figure 1 , 

 was 20° F., the same as the temperature of the air. From figures 2 

 and 3 it will be seen that the shrinkage in weight from January 5 to 

 February 24, 50 days, was 30 pounds, or slightly more than one-tenth 

 of 1 per cent. The temperature of the corn at this time, as shown by 

 the average of the readings of the four thermometers, was 32.5° F. 

 an increase of 12.5 degrees over the average temperature of the corn 

 when it was placed on the scale. The average of the daily mean air 

 temperatures for one week prior to February 24 was 33° F., or 13 

 degrees above the temperature of the air at the beginning of the 

 experiment. From February 24 to April 8, 43 days, the loss in weight 

 amounted to an additional 30 pounds, making a shrinkage of 60 

 pounds, or approximately two-tenths of 1 per cent, for the first 93 

 days of the test. The increase in the average temperature of the corn 

 during this period of 93 days from the beginning of the test was 

 26.3 degrees. 



On April 21 the average temperature of the corn was 69.5° F., an 

 increase of 23.2 degrees for the 13 days from April 8 to April 21, dur- 

 ing which period there was a further loss in weight of 47.5 pounds^ 

 or neaily two-tenths of 1 per cent, and for the whole period, January 

 5 to April 21, 106 days, the shrinkage amounted to 107.5 pounds, or 

 approximately four-tenths of 1 per cent. The highest temperature 

 at any point in the corn at tliis time was 87° F., as was shown by 

 thermometers Nos. 3 and 4 in the ui)per part of the grain, while 

 thermometers Nos. 1 and 2 showed a temperature of only 51° and 

 53° F., res{)ectively. At this time the corn in the scale showed the 

 fii-«t distinct signs of going out of condition, and this deterioration 



[Cir. 81] 



