l/ 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

 Of Nature trusts the mind which builds for aye." — Wordsworth. 



No. 2563, Vol. 102] THURSDAY, DECEMBER 12. 1918 



[Price Ninepence. 



Rciftstered «s a Newspaper at thr General Post Office ) 



[All Kichts Reserved 



^BALANCES &WEIGHTS 



Graphite-Selenium Cells 



FOURNIER D'ALBE'S PATTERN. 



Great Stability and High Efficiency. 



With a sensitive Se surface of 5 sq. cm. and a voltage 20 the 

 additional current obtainable at various illuminations (in 

 metre-candles) is : — 



At 1 m.c. 

 At 50 „ 

 At 500 „ 



1 milliamp. 

 1 



2 ., 



For particulars and prices apply to the Sole AGSNT3 : 



John J. Griffin & Sons, 



Makers of Physical and Electrical Apparatus, 



Kemble Street, KiNGSWAY, 

 LONDON, W.C. 2 



REYNOLDS & BRANSON, Ltd., 



Chemical and Scientific Instrument Makers to His Majesty's 

 Government (Home and Overseas Dominions). 



LABORATORY FURNISHERS and MANUFACTURING CHEMISTS. 



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equipped 



with Benches, Fume 



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iv. 



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Nickel Ware, and Filter Papers. 



Apparatus in Glass, Metal, or Wood made 



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CATALOGUES POST FHEK. 

 Enquiries for Technical Chemicals in quantity solicited. 



14 COMMERCIAL STREET, LEEDS. 



ACCURATE 



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 THERMOMETERS. 



Send a note of your requirements 



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NEGRETTI & ZAMBRA, 

 38 HOLBORN VIADUCT, E.C. 1 



5 LEAD ^ V C H ^ LL ST - LONDON. 



(D»- Our City Branch is at 5 Uadcnhall Street, EC. 3 



