1250 
core A77; with heating and thermometer wires (Comm. N°. 148, Oct. 
1914, N°. 147a, June 1915) is screwed. 
For the purpose of promoting the heat conduction in the condensed 
gas a quantity of copper gauze f, is introduced into the flask and 
soldered to the walls. Three copper rods f, serve the same purpose, 
particularly also to prevent that, when the solidified gas melts again 
and vaporizes, that part of it which is nearest to the openings of 
the tubes d,, d,, should remain solid longer than the other part and 
so obstruct the streaming off of the liquid or the gas. Moreover from 
the reservoir H a small quantity of hydrogen gas could be introduced 
to convey the heat between the crystals or parts of the solid gas which 
might lie side by side thermally isolated, when the vapour pressure of 
the condensed gas is too small to provide itself for the heat convection. 
The conduction of heat in the nitrogen appeared to be sufficiently 
rapid, to render the temperature uniform within a couple of minutes 
after the heating in the calorimetric experiment. On the other hand 
the heat conduction through the glass tubes 6,, 6, was sufficiently 
small, so that with a good vacuum inside the calorimeter glass the 
temperature of the calorimeter showed before and after the experi- 
ment a sufficiently slow rate of!change. As examples we give in 
Figs. 8a and 4 the galvanometer-curve in two measurements ‘at 15.3 
and 61.7° K. respectively, ef. table I). 
a 
3a 
so 
SA, Pe OR ake ace key eee 
a sz 
cae) oy peor en 
30 i 
a _ 
ze 
A ris 
he Ei 
EK Eh ob cb ib wb zb 2d zb shores En ido ido we: 2b 2do zb ado seb zeb sch ach dowzeer 
Fig. 3a. ce 
The capacity of the flask # is about 50 eem. 
For the measurements we refer further to the description in 
Comm. N°. 143 § 2, for the charcoal tube for keeping up the 
vacuum, which is left out in Fig. 1, to Comm. N°. 143 Fig. 1. 
As explained in Comm. N°. 147a (These Proceedings September 
1915, p. 485 note 3) the scale of the thermometer wire Au‚s in the 
