241 



An Improved Form of Mercury Vapor Air Pump. 



Chas. T. Knipp — University of Illinois. 



(Abstract.) 



The mercury vapor pump described in this paper retains the same 

 simple valve arrangement described recently by the writer,* but on the 

 other hand replaces the umbrella that deflected the mercury vapor 

 downward through an annular throat by the commonly used aspirator 

 nozzle through which the vapor issues vertically upwards. This neces- 

 sitates an interchange of connections leading to the supporting pump 

 and the vessel to be exhausted. 



This pump, single stage, will operate on any oil supporting pump 

 of the grade of the Nelson pump. In addition to its speed, its simplicity 

 of design and ease of construction are important points, and when con- 

 structed of pyrex glass is durable. 



The paper also gives the data obtained when several of these pumps 

 are placed in tandem. Again, a three-stage pump retaining the same 

 general principle is described, designed to operate on a poorly working 

 water aspirator as a supporting pump. The mercury vapor for each 

 stage is supplied from the same boiler, yet at diff"erent pressures, the 

 highest pressure to the first stage exhausting into the aspirator. Sam- 

 ple pumps and sketches were exhibited. 



Phys. Rev., N. S. IX. No. 3. Mai'ch, 1017. 



16—11994 



