422 



The Nadir of Teiuppratiire. 



[.hi IK 



l')08 



into the neck of the liciuid hydi-ogeii tiihe, uiid the stopcock opened 

 to the chai'coal condenser. The lifjiiid hydrogen is thus subjeeted 

 to the exhanst of the large cooled charcoal bull), and is seen to 

 boil up rapidly, and very soon opaque solid hydi-ogen appears in ever- 

 growing amount, until the whole mass of hydrogen is frozen to a 

 snowy froth. 



r^ B 



Fig. G. 



In this connection it may l)e pointed out that assuming the 

 temperature of boiling helium to be about 5" absolute, then charcoal 

 in liquid hydrogen under exhaustion, along with proper isolation of 

 the helium from influx of heat, Avould very probably l)e able in a 

 similar manner to bring about* the production of solid helium, and 

 we may be certain that if the charcoal could be cooled in liquid 

 helium, then it (X)uld l)e solidified even if its solid tension was 



exceedingly small. 



[.1. 1).] 



I.ONI10N: ritlNTKK liV W/M.IAM rhOWES AXD SONS, MMITEn 

 GBEAT WINDMll,!, SXKKKT, \V., ANU DtIKE STKEKT, STAMloKl' STUKET, S. 



