24 



Equipment of the Class Rooms. 



50130. 1:8. 



50 131. 1 : 3. 



50 139. 1 : 5. 



50 136. 1:10. 







^-* 



> 



o 



er 



CD 



Q 



> 



I 



v: 



50 132. 1 : 10. 



50 134. 1 : 10. 



50138. 1:8. 



50 140. 1 : 4. 



50.130. Water Air Pump, as 'No. 50,129, with mercurial pressure gauge (F i g u r e), on polished - s - fl - 

 oak board. Price without mercury for charging 2.5.0 



50.131. Water Air Pump (Arzberger and Z u 1 k o w s k y's), Figure, with Metal 

 Vacuum Gauge, 50 mm in diameter and with screw clamp for fixing to a stand, water 

 tap standard or the like. Price, without stand 



50.132. - The preceding, Figure, with stand, for placing on the table 



50.133. - The preceding, with walldisc 



50.134. Glass Water Air Pump (W e t z e 1 's), with stand (Figure), with cock, overflow 

 vessel, barometric gauge and rubber hose reinforced with metal spiral 



This air pump can only be used with a water pressure of 3 6 atmospheres ; it works excellently. 



50.135. - -The preceding, without stand 



The air pump in this construction is intended for connecting directly to water hose taps. 



50.136. Water Air Pump (B u n s e n's), Figure, of metal, nickelled, with Metal Vacuum 

 Gauge 100 mm diameter, on polished board, arranged for screwing on the wall, with 

 water bag, but without fall pipe 



This air pump does not need any water pressure, but a narrow fall pipe at least 10m long is necessary. 



50.137. - The preceding, with mercurial pressure gauge 



1. 18. 



2. 0. 

 1.17.0 



1. 3.0 

 0. 3. 6 



2. 15. 



2. 5.0 



Cl. 3854, 3761, 527?, 2 . 

 17, 18. 521(7, -'-> 



