13 



In order to compare machine milking- with experienced and inex- 

 perienced hand milkers, two of the ten cows were milked by a hand ex- 

 pert for the first eight days of November and two others were milked by 

 an inexperienced person. At the end of eight days, hand milkers were 

 reversed for seven days, i.e., the expert took the two cows milked by the 

 inexperienced person and the inexperienced person took those milked by 

 the expert. For the last fifteen days of November these cows were milked 

 with the machine and each milking was weighed separately from each 

 cow. The table shows that the average daily yield was increased by the 

 expert during the second week by over two pounds daily with one cow 

 and seven-tenths of a pound daily with the other. The two cows milked 

 the first week by the expert and the second week by an inexperienced 

 milker showed a loss of one pound of milk daily with one cow and prac- 

 tically the same with the other when milked by the inexperienced milker. 



During the next two weeks, when these four cows should have main- 

 tained their milk flow, the results were downward with all four cows 

 when milked with the machine. 



Table Showing Daily Yield of Four Cows from Expert and Inexperienced 

 Hand Milkers and Machine Milking, November, iqo6. 



Error Introduced by Weighing One Day in Seven. 



Error in a two-weeks period. In the case of short test periods with 

 the milking machine, where the milk is weighed every seventh day, a 

 certain amount of error is introduced. In all the two-week tests, com- 

 paring hand and machine milking, the pounds of milk were calculated 

 by taking the average of three daily weighings and multiplying this by 

 14 to get the pounds of milk given by each cow for two weeks. In a 

 short period, if the weighings were made, say, on the first and eighth 

 days of the period and the calculations for the following weeks be based 



