Thermodynamic Properties of Air. 



293 



to transfer the gas to the eudiometer, where its quantity is to 

 be measured. This arrangement is quite similar in plan to 

 that used by Wroblewski in his already-mentioned investi- 

 gations on hydrogen. As regards details, I have adopted, 

 after several unsuccessful trials, the following construction, 

 which proved quite trustworthy and convenient : — 



A brass cylinder, A (fig. 2), is bored along its axis from 



Fig. 2. 



both ends ; in its centre the'^borings are connected by a very 

 short and narrow channel rs, communicating with another 

 vertical channel, t, of very small capacity. The channel t is 

 connected with the stem a in the following manner: — On the 

 upper end of g there is cemented, by means of fine sealing- 

 wax, a thick-walled brass tube B, provided near its lower end 

 with a collar. The end of the glass stem, cut perpendicularly 

 to its length, protrudes some -f 5 of a millimetre from the flat 

 end of B. The glass bulb s, with its stem and brass tube B, 

 form a separate piece, which is to be connected tightly with 

 the cylinder A. This is done by means of the external screw 

 M, in a way sufficiently indicated by the figure. To ensure 



