Rotary Enclosed Vacuum Pumps. Mercury Air Pumps. 



397 



52988. 1:15. 



52989. 1 : 15. 



">L',!)X3. Rotary High- Vacuum-Pump, Figure, Semi-Enclosed Vacuum Pump for belt or hand t s. d. 



drive; gives alone up to 0.05 mm mercury column (Ztschr. f. d. phys. u. elieni. 1". 19, 



I'.tOfi, p. 73) * 15.15.0 



A higher vacuum than that mentioned above can be attained by using a separate preliminary 

 pump. <'. g. a water air pump. For obtaining a vacuum of O.li(i:{ nun it is advisable to use a. second 

 pump, built like the above, aa |ir'liininary pump (see also No. .">:>. !)S.~>). The best speed is about 4nii i. 

 p. m. when working without preliminary pump, and when working with preliminary pump about 

 2(10 r. p. in. 



">2,!>X4. - - i d c in. with 110 volt Direct Current Motor, on one hoard, with starter . . . 30. 0. 



The price varies if the motors a"e for a different current or voltage. In the ease of 3-phase or 

 alternating current, kindly state frequency. 



>2.9X5. Two High Vacuum Pumps with 110 volt Direct Current Motor, on one board, one working 

 as a preliminary pump; vacuum attainable, 0.003 rnm mercury column; quantity of 

 air sucked up 70 and 35 litres per minute respectively 50. 0.0 



Mercury Vacuum Pumps. 



52. !*;. Mercury Vacuum Pump after Geissler, Figure, with polished oak stand; capacity 

 of transport vessel, 1 1.5 litre 



The glass parts are the best product of the glass blower and are fitted with first rate cocks: the 

 pump has three attachments for glass apparatus, massive and handy winding device; all metal parts 

 excellently finished. Can. it desired, be provided with Supports, so as to be able to connect the air 

 pump, by a length of tubing, with plates N'os. 50,139 50,142, p. 400. 



10. 0. 



52. !IS7. Mercury Vacuum Pump after Topler-Hagen-Neesen, Figure (M. P. I, Figs. 527 528 



k[566 567]), with winding device, with all latest improvements 



,988. Mercury Vacuum Pump after Sprengel, Figure, without cocks, on stand, holding 

 1 litre mercury (W. 1). Fig. 175 [160]) 





J,989. - - i d e m, after (iieiner and Friedrichs, Figure (Fr. phys. Techn. I, 2, Fig. 2614 

 [I, Fig. 323]) . . 



Cl. !4li, 950. 



9. 0.0 

 3. 15. 

 7. 10. 



