874 EXPEEIMENT STATION RECORD. [Vol.35 



bility reciprocal between balances with and witliout load was found to be con- 

 siderably greater in tbe 6 to 12 bottle balances than in the 1 to 4 bottle balances. 

 It was also found that the 12 bottle balances with and without load are very- 

 much less sensitive than the 1 to 4 bottle balances. Of the 193 balances in- 

 spected 31 were condemned because they failed to meet the requirement of 

 sensibility reciprocal of 0.1 gm. Some of the balances were condemned because 

 of inaccuracy of graduations on the beam which carries the traveling poise. 



A comparison was made of duplicate tests made from the same samples of 

 cream and weighed on a given balance. These tests and retests represented 

 4,623 samples of cream tested in commercial creameries, and four different types 

 of balances were used. With the use of a one-bottle balance with a sensibility 

 reciprocal of 0.01 gm. and involving 3,540 samples of cream, 96.43 per cent of 

 the retests checked, with a four-bottle balance having a sensibility reciprocal 

 of 0.01 gm. 79.52 per cent of the tests and retests of 376 samples checked ; with 

 a twelve-bottle balance having a sensibility reciprocal of 0.01 gm. 80.43 per cent 

 of the tests and retests of 460 samples checked ; and with a twelve-bottle balance 

 having a sensibility reciprocal of 0.1 gm. the tests and retests of 247 samples 

 checked in only 60.71 per cent of the cases. 



In order to eliminate the effect of differences in technique in preparing the 

 samples of cream and the personal equation in the manipulation of balances, 

 18 samples of cream were tested in duplicate using 16 different balances with 

 each sample for weighing the cream. The work was done by one person under 

 uniform conditions. With six balances having a sensibility reciprocal of 0.01 

 gm., and two balances having a sensibility reciprocal of 0.03 gm., 100 per cent 

 of the duplicate tests checked ; with two balances having sensibility reciprocals 

 of 0.02 gm. and 0.03 gm., respectively, 94.4 per cent ; with three balances having 

 a sensibility reciprocal of 0.05 gm., 92.6 per cent; with one balance having a 

 sensibility reciprocal of 0.08 gm., 77.8 per cent ; and with two balances having a 

 sensibility reciprocal of 0.1 gm., only 36.1 per cent. In these tests all duplicate 

 tests varying within 0.5 per cent were counted as checks. 



The effect of the degree of sensitiveness in cream balances on the speed of 

 the operator is discussed. 



Cooling cream on the farm, O. F. Htjnzikeb, H. C. Mills, and H. B. Switzeb 

 (Indiana Sta. Bui. 188 {1916), pp. 1087-1118, figs. i6).— This bulletin reports 

 tlie results of an experiment to show the effects of cooling cream promptly and 

 properly on the farm. 



Each of two cream routes of 20 patrons each of the Purdue University cream- 

 ery was divided into two parts, and a preliminary test carried on which showed 

 that the two groups were producing cream of similar quality under similar 

 sanitary conditions. One-half of the patrons then received cream-cooling tanks 

 and the other half took care of their cream without the use of special cooling 

 tanks. The cream from each set of patrons was hauled to the creamery twice 

 a week and received the same treatment in the butter-making process. The 

 finished butter was scored at the station by three judges, shipped to New York 

 and there scored by three judges, and sold on the basis of its market value. 



During the experiment proper, which extended throughout August, 1915, the 

 weather was wet and unusually cool and consequently the difference between 

 the atmospheric temperature and the temperature of the water used for cooling 

 was comparatively very slight. Notwithstanding this fact, it was found that 

 the use of the cooling tanks produced a very marked improvement in the quality 

 of the cream and of the butter made therefrom. Cream from the patrons using 

 cooling tanks averaged 0.38 per cent acidity and scored 91.25 per cent, and 

 cream from the patrons using no tanks averaged 0.52 per cent acidity and 

 scored 88.75 per cent. It was noted that in the case of the tank cream the 



