NIP. -V_'-!H. 



Stopcock Vacuum Pumps. 



387 



52 893. 1 : 4. 



52894. 1:5. 



52 892. 1 : 4. 



s. d. 

 52,890. Device for considerably ratifying the ah in the clearance before each stroke. Extra price 1. 4.0 



Can only be used for Pumps Nos. 52,887, 52,888 and 52,889. 



52,893 . Stopcock Vacuum Pump with 2 Barrels, Figure, barrels 60 mm internal diameter 

 and .'?.">() mm length, with glass plate 280 mm diameter, with Grassmann cock for entirely 

 obviating the influence of clearance; without receiver 



This Vacuum Pump rarifies twice as quickly as a single-barrel one and exhausts up to 1.5 or 2 mm. 

 Largest Receiver for use with above: No. 53,015 



52, 892. Model of a Babinet Vacuum Pump Stopcock, F i g u r e, of wood 



52,893. Model of a Grassmann Vacuum Pump Stopcock, F i g u r e, of wood 



52.X91. Vacuum Pump after Bianchi, Figure, with Glass Barrel, double-acting, with 

 steel valves placed outside the barrel, with sleel Babinet stopcock, very nicely constructed, 

 with neat, firm iron base; Glass Plate 280 mm diameter on special tripod, with Baro- 

 meter Gauge, 300 mm high, finnly attached; connecting tubing screwed at both ends 



The Vacuum I'limp gives 4 mm tor large and 2 mm exhaustion for small receivers in an extra- 

 ordinarily >lmrl -|i;n-c of time. The valves contrary to (he original construction described in most 

 text-books being place:! outside the cylinder can be very easily cleaned. Price is exclusive of Re- 

 ceivers. Largest Receiver for use with above: No. .">:!. o|.~, 



15.10.0 



0. 6. 6 



1. 0. 

 1. 0.0 



31. 0. 



i). 6. 6 



Cl. 934, 996, 5894, 

 995. 



