832 



The kydrostatic press. 



The pressure is furnished by a Schaffer and BudeiNberg hydro- 

 static press of the known construction, only heavier" than usual 

 according to the circumstances. This press is provided witli 4 cocks 



to the pressure balanct 



to the apparatus 



to the fore pump 



Fig. 11. 



(fig. Jl). The tube S^ is in connection with one of them V^, and 

 it is tliis cock that is turned off when in the evening tlie work is 

 suspended after the measuring tube has been tilled with gas. (cf. 

 above p. 829). V^ can open, i-esp. break off tlie communication 

 with tlie large pressure t)alance. Here the tube ends, which joins 

 the pump with the "head" A and the space C {iig. 1) of the 

 pressure balance. All the couplings are effected steel to steel as 

 above. V^ is the exit-valve,. V^ bars the way to the fore pump. 

 This fore pump is an ordinary oil suction- and forcing pump, which 

 can carry the pressure up to 800 atm. So when the whole space 

 beyond V^ has been tilled up to that pressure, V^ is closed, and 

 the pressure is fui'ther increased by means of the large wheel of 

 the press. On the way between V^ and the fore pump there is still 

 a j_-piece. The branch way which is formed here, may be shut 

 off by a high-pressure cock of ordinary construction. This branch 



