THE PASTEURIZATION OF MILK 



holder. If one recorder only is in use, it is more 

 important that it be placed at the holder outlet. 

 It is evident that if there is a serious loss of heat 

 during the holding process due either to imper- 

 fect insulation or to insufficient preliminary heating 

 of the holder, then the milk would not be satisfac- 

 torily pasteurized, since some of the dangerous 

 organisms originally in the milk may escape de- 

 struction. The holder recorder indicates this. 



The various recording instruments upon the 

 market differ in this one particular, namely, that 

 in one form ether, or a similar volatile fluid, is 

 used in the thermometer bulb and capillary tube, 

 while in the other, the bulb and tube are filled with 

 mercury. One of the former is shown in Fig. 30, 

 while the mercury bulb is shown in Fig. 31. There 

 is a variation also in the method employed for 

 regulating the recording arm. In a form of re- 

 corder not shown, another form of adjusting screw 

 is attached to the recording arm, and an improved 

 device is used for securing the paper chart to the 

 face of the instrument. 



In the selection of a recording instrument, one 

 of the most important points to consider is its sen- 

 sitiveness to rapid or frequent changes in tempera- 

 142 



