H. KAMERLraGH ONNES and C. A. CROMMELIN: "On the measurement of very low temperatures. VI. Improvements of the protected thermoelements: a batter; 

 of standard-thermoelements and its use for thei-mo-electric determinations of temperature." 



fig. 5. 



ng. 2. fig. 3 



•c 20 



L.---.-.-U_._.J' 



Hiuti-cJiugs Royal Acad Amsterdam. Vol. VI. 



