A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

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



No. 2753, Vol. no] 



SATURDAY, AUGUST 5, 1922 [Price One Shilling 



1 Newspaper at the General Post Office,] 



[All Rights Re 



BALANCES & WEIGHTS 



SPECTROMETERS 



Particulars and Prices on application to— 



JOHN J. GRIFFIN & SONS, L TD 



Kemble Street, Kingsway, 

 London, W.C.2. 



DO YOU KNOW 



VITREOSIL LABORATORY WARE 



Incomparably Superior 

 to any other similar Material? 



Constant in Weight, Reliable, 

 and Reasonable in Price. 

 Write for Pocket Edition of 



Price List. ~ - 



HEAT 

 PROOF 



f^Qpt 



ACID 

 PROOF 



SOLE MANUFACTURERS 



THE THERMAL SYNDICATE, LTD. 



VITREOSIL WORKS- WALLSEND-ON-TYNE. 

 LONDON DEPOT-28 VICTORIA ST., S.W.I. 



BAROGRAPHS 



Four rubber feet to the base 

 — a self - adjusting pen arm — 

 a supporting rod to the cover — 

 these are some of the refinements 

 on our Recording Barometers. 

 Write for price list " B. 3." 



N'EGRETTI © ZAMBRA 



38.HOLBORN VIADUCT. E.C.I. 

 LONDON. 



FACTORY 

 WORKS, 



HALF-MOON 

 BARNSBURY. 



