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Sir James Dewar 



[Jan. 17,. 



When using the vessels for any form of oxygen supply it was 

 found safer to have some holes near the top and bottom of the outer 

 metal case. The glass neck of the vacuum flask was also covered 

 in all cases, to the depth of an inch inside and outside, with thin 

 assay lead (see Fig. 4) to minimise the risk of fracture through 

 splashes of liquid air when the vessel was filled, or from accidental 



Vic. 5. 



contact of tlie inside metal parts, when fixing the cap. _ It is also 

 an advantage to soak any corrugated [)a,per packing in melted 

 paraffin, to prevent the al)Sor[)ti()n of water wlien cooled, and to^ 

 facilitate the insertion of glass refills. The glass refill must fit air- 

 tight into the ne(;k of the ontei' metal case. 



