82 Missouri A'gricultural Report. 



(3) A gauge. 



(4) A regulator. 



(5) A pipe system. 



(6) The milkers. 



There are three ways of producing vacuum. First, by means 

 of a vacuum pump, which can be operated by any motive power. 

 Second, by a steam air exhauster. Third, by means of a water 

 vacuum pump. The vacuum pump is constructed similar to that 

 for an air pump, except that the mechanism is some finer and the 

 valves are more closely fitted and especially designed for pumping 

 air. This pump can be operated by means of a gasoline engine, 

 steam engine, bull tread power, sweep power, or electric power, or 

 in fact any form of power that is practical on a farm. A bull tread 

 power is by all means the cheapest, but it requires considerable 

 diligence to train an animal to produce a steady and uniform power. 



A vacuum produced by means of a steam air exhauster has 

 proven to be a very practical thing for the average farm. It is 

 simple in machanism, not easily broken, and works with certainty, 

 providing there can be steam generated. The same principle in- 

 volved in drawing water by means of steam can also be used in 

 drawing air, except that it needs a slight change in the arrangement 

 of the steam jet in relation to the exhaust chamber. The vacuum, 

 can also be produced by means of a vacuum water pump. Owing 

 to the large amount of water and the great pressure necessary, 

 however, it is hardly possible to produce vacuum economically with 

 this style of pump. 



The purpose of the vacuum chamber is to keep a constant sup- 

 ply of vacuum on hand and to provide for the rush of the air 

 through the teat cups in the case of putting on or taking off the cups 

 from the teat. 



The vacuum gauge shows the number of inches of vacuum 

 necessary to draw the milk. The safety valve regulates the vacuum 

 pressure so that it will not become too high. An excess of vacuum 

 will injure the cow's teat, hence in order to maintain a constant 

 pressure this regulating valve is very essential. 



It is very important that there should be a steady and constant 

 vacuum during the milking operation. Dairymen well know that 

 in the case of hand milking if one were to stop for a time when 

 the cow is partially milked and then begin again and finish, the 

 chances are that there would not only be a decrease in the yield, but 

 the milk would be of poorer quality. A similar effect is produced 

 in the case of machine milking. If the engine or whatever power 



