SCIENCE-ADVERTISEMENTS 



Gaede Molecular Air Pump 



MADE BY E. LEYBOLD'S NACHFOLGER 



Operates on a new 

 and interesting princi- 

 ple, using no mercury. 

 Will evacuate a 6 liter 

 vessel from 10 mm. to 

 00001 mm. in 3 min- 

 utes. With its use, 

 \apor may be pumped 

 as (veil as gases, which 

 IS a very important 

 feature. 



Illustrated Descriptive 

 Price list No. 6, fully 

 describing'^this pump, 

 wdl be „ sent free on 

 - request. 



JAMES G. BIDDLE 



1211-13 ARCH ST. Special Representative PHILADELPHIA, PA. 



When in Philadelphia be sure to visit our Permanent Exhibit of Bcientiflc;apparatvig. 



The Jones 



FILING 

 BOXES 



Are Made 

 In Any Size 



That Pamphlet Is Some- 

 where In This Pile 



Under the oircumstances, vf hat hope have yon of finding it? 



Keep yonr pamphlets in the JONES FILING BOXES 

 and you can find any of them withont delay. Of the various 

 styles, there is one box, at least, that Tvill give you good 

 service. 



We have a catalog illustrating these boxes. Mail the 

 coupon below for a copy of It. 



THE JESSE JONES PAPER BOX CO. 



613-615 Commerce Street PHILADELPHIA 



JESSE JONES PAPER BOX CO., 



613-61S Commerce St., Philadelphia 



Gentlemen: — Please send me your txx)fclet 

 giving full information about Jease Jones Fil- 

 ing Boxes. 



Name 



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