;xl 



NATURE 



[December 29, 192 1 



BELUNGHAM-STANLEY 



Polarimeters and Refractometers 

 are the Key instruments to 

 successful industrial research. 



% 



List of users and full particulars 

 from 



BELLINGHAM & STANLEY Ltd. 



71 HORNSEY RISE, 



LONDON, N.I 9. 



Tel. Hornsey 2270. 



DARTON'S 



BAROGRAPHS, THERMOGRAPHS, 



HYGROGRAPHS, 

 STANDARD BAROMETERS, ETC. 



BAROGRAPH, as illustrated, in oak or 



mahogany, £10 10s. 



Ditto, with bevelled plate glasses, and chart 



drawer, £12 128. 



Can be obtained through all Laboratory 

 Furnishers, or from the Makers : 



F. DARTON & CO. 



Contractors to H.M. Coiernment 



142 St. John Street, London, E.G. 1. 



Laboratory Glassware 



BEAKERS, FLASKS, 

 RETORTS, &c. 



Porcelain 



CRUCIBLES AND BASINS. 



Filter Papers 

 Pure Chemicals 



JOHN J. GRIFFIN & SONS, 



LTD.. 



KEMBLE STREET, KINGSWAY, 

 LONDON, W.C.2. 



LEITZ 



MICROSCOPES, 



MICROTOMES, 



PHOTO- 



MICROGRAPHI^ 



Apparatus, 



EPIDIASCOPES, 



PROJECTION- 

 DRAWING 



Apparatus, 



PRISMATIC 



BINOCULARS. 



NEW SILVERMAN 

 ILLUMINATOR 



for Opaque 

 Objects. 



British Agents: 



OGILVY & CO. 



18 BLOOMSBURY SQUARE, LONDON, W.C.I 



Optical and Mechanical Repairs executed on the Premises. 



