Di;. M. TJLVYERS. MR. (i. SENTIM;, AND DR. A. .TAQUEROD 
15-t 
the same themimiieters show an even closer agreement; this, as we shall presently 
show, is due to the tact that liquid hydrogen, unlike liquid oxygen, does not tend to 
become superheated. 
It is a somewhat remarkable fact that pure oxygen when liquified can only with 
difficulty he made to l)oil steadily. By passing a rapid current of oxygen or air 
through tlie liquid a fairly steady temperature may he maintained, but if the current 
is sto])ped the temperature may rise more than one degree. This probably accounts 
for the fact that the temperatures found Ijy us are in every case somewhat lower 
than those of other oljservers, who, without exception, measured the pressure on the 
mass of liquid in which the thermometei' was immersed. This source of error we 
have, however, taken great pains to eliminate ; foi' the accuracy of the actual 
measurements, the concordance of the olrservation made by means of the different 
tliermomf'tei’S furruslies a sufficient guarantee. 
