Section III, 1921 



[93] 



Trans. R.S.C. 



Automatic Mercury Pump 



By D. F. Stedman 



Presented by Professor E. H. Archibald, F. R.S.C. 



(Read May Meeting, 1921) 



This pump was designed primarily to use as small an amount of 

 mercury as possible, and thus have none of the troublesome 76 cm. 

 connections except in the gauge. 



The whole pump is operated by an ordinary water pump which 

 should produce a vacuum of at least 1.5 — 2 cms. of mercury. When 

 a little air enters through "a" it breaks the column of mercury here, 

 raises the section to "b," and drops it into one side of a U-tube. 

 This displaces mercury on the other side which runs down the spiral 

 fall tube "c," pushing the air in front of it through the mercury pool 

 in bulb "d." As soon as the mercury is out of the top of tube "a" 

 the diminished pressure allows the mercury to rise in tube to level in 

 'V and the process is repeated. 



flUTOM/RTJC MERCURY PUMP 



TO lyK^r£Pl PUMP 



TO 

 /^'■LEOD 

 G/IUGS, £TC. 



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