NA TURE 



I 



All other air 

 pumps superseded. 



THE. 



ff 



"GERYK 



{Fleuss Patent) 



Vacuum Pump. 



R-esults hitherto only pos- 

 sible with mercury pumps 

 are readily obtainable by 

 the " Geryk." Used by 

 all leading scientists. Far 

 more rapid than any other 



vacuum pump. 

 Price from Write for 



£4:5:0. LIST F.45. 



PuUometet engineering G^UJ 



Cia* etnulfonivorhs. Reading. 



. 



REYNOLDS & BRANSON, L^- 



TD. 



THE 



RYSTOS 

 STAND 

 DEVELOPING 

 TANK. 



Fop Developing plates or 

 cut films slowly in a very 



weak developer. 

 Clean in use ; gives excel- 

 lent results with a minimum 

 of trouble, 



MADE OF STOUT 



POLISHED COPPER. 



Tanl< to take 6 plates 15" ;■: 12", and with Adapters to suit 



any smaller plate; complete, «i : lO : o 



rills arr.ingemenl is specially recommended to Radiogl.^phe^s and other 



Scientific Photographers. 



Tank to hold 1 doz. J plates only 4/6 each. 



Tank to hold 1 doz. 5" x 4" plates only S/- ,, 



Tank to hold 1 doz, S plates only 6,- 



Poslage on any of above three sizes, 4d, extra. 



NEW PHOTOGRAPHIC PRICE LIST, 25th EDITION, ON 

 APPLICATION. 



14 COMMERCIAL STREET, LEEDS. 



[August 31, 1905 



.A. Iia"B"W I».A.TTEK.BB" 



FORTIN'S 

 STANDARD BAROMETER 



;tered U. 

 by the 



No. 



illustrati( 





; FULLY 



Regii 



As will be seen 

 built on original lit 



By the absence of the ordinary tubular encio 

 usual form of instrument) the mercurial columi 

 EXPOSED to view, NO SHADOWS are 

 the column, and therefore an extremely accu 

 stantaneous reading is made possible. The scales being 

 graduated upon the flat side p eces the DIVISIONS AND 

 FIGURES ARE ALWAYS IN VIEW, and the vernier 

 is very much more legible than in the ordinary tubular 

 patterns. 



The bore of the tube is 0'5 inch. 



The scales are graduated in inches and millimetres, and, 

 by means of the verniers, are capable of being .sub-divided 

 to read lo 0-002 inches and CM m/m. 



The att.ached Thermometer on the body of the instru- 

 ment is gr.aduateH in Fahrenheit and Centigrade scales. 



It is the BOLDEST Standard Barometer made. 



The PRICE IS LOWER than that of any other form 

 of Standard Barometer of the same dimensions. 



It yields readings equally clcse as the highest priced 

 instruments. 



Price complete, mounted on handsome Polished 

 Solid Mahogany Board, with Brackets for Sus- 

 pension, and Opal Glass Reflectors, 



£7 10s. Od. 



SMALLER SIZE, "THE STUDENTS," 



Li - designed for Schools for demonstration work, and small 



private Observatories; bore '25 ; reading to -01 inCh 



and -1 millimetre, £3 7s, 6d. 



mr-f S,^/c' Manufacturers and Pr,,f.ri,-lors ,y Ike RegJ. Design: 



id PASTORELLI&RAPKIN, Ltd., 



^0 46 hatton garden, london. e.g. 



^^ Wholesale Makers of all kinds of Meteorolocical Instruments. 



Telegrams : R.^tkin, London. 

 Nat. Tel.: 19S1 Holborn. Estd. isoyears. 



ing any of our Instru- 



N.B.— If any difTiculty be found in sec 

 ments through your Dealer, kindly 



rith 1 



JOHN J. GRIFFIN & SONS, 



LTD., 



Manufacturers of 



SCIENTIFIC 

 APPARATUS. 



<X^M^ 



STANDARD 



COMPLETE EQUIPMENTS 



FOR 



CHEMICAL, BACTERIOLOGICAL, 



PHYSICAL, and 



METALLURGICAL LABORATORIES. 



Sardinia Street, London, W.C. 



