di\ 



I 



NA TURE 



All other air 

 pumps superseded. 



THE. 



"GERYK" 



(Fleuss Patent) 



Vacuum Pump. 





R-esults hitherto only pos 

 sible with mercury pumps 

 are readily obtainable by 

 the " GeryR." Used by 

 all leading scientists. Far 

 more rapid than any other 



vacuum pump. 



Price from Write for 



£4:5:0. LIST F.45 



Pulftometer enginecrinp e?.,Vi* 



QtM €(fn*lronivar»is. ficadin j. 



[August 17, 1905 

 THE NEW "STUDENT'S" 



STANDARD BAROMETER. 



inis Instrument has been designed to meet the re- 

 quirements of Students and others who find the need of 



Lc^hlli""' ™ 'i° "'" S"^ exact readings, and 

 cost but a moderate sum. 



It appeals especially to Colleges and Schools for 

 demonstration purposes. 

 The construction is on that of the well-known " Fortin " 

 iple. The level of the cistern mercury is reducible 



:tly the 



ial column is -25 inch, and 

 readine. The scales, by 

 pable of being read 



It 



nted 



li^hed, solid mahogany board, with plates for attach- 

 -lit to wall, opal glass reflectors for reading off, and 

 lews for vertical adjustment. 



portions are all well bronzed and lacquered, 



ed br 



We confidently recommend this Instrument for use 

 blandard in Colleges and Schools, private Obser 



ries. and by Gas and other Engineers. 



Price, complete, mounted as illustrated, 



£3 7 6 each, 

 may be had with one scale (either inches or mi 



etresj, and with thermometer on other scale, at sa 



urate 



II«~ Nature says :— " Provides 

 ment at a moderate cost." 



FULL SIZE STANDARD BAROMETER of 



same design, bore 05" diameter, inches and millimeter 

 sciles, verniers reading to o'ooa inch and 01 m/m, on 

 polished mahogany board with brackets and opal glass 

 reflectors, £7 10 O 



Sole Manufacturers and Proprietors of the 

 Registered Design. 



PASTORELLI & RAPKIN, Ltd.. 



46 HATTON GARDEN, LONDON, E.G. 



Wholesjie Makers of jil kinds of Meteorolooical Instruments 



Contractors to H.M. Government. Estd. ryjo 

 lelegrams, " Rapkin, London." Telephone, rqSi Holborn 



W.H.SMITH ISDN'S 



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