A WEEKLY ILLUSTRATED JOURNAL OF SCIEI 



'* To the solid ground 

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



No. 2253, Vol. go] 



THURSDAY. JANUARY 2, 191; 



[Price Sixpence 



Newspaper at the General Post Office.) 



(All Rights Reserved. 



BALANCES &WEIGHTS 



John J. GRIFFIN &S°J 



MAKERS OF 



Physical Apparatus 



THE GRAY-BURNSIDE 



MOTOR GYROSTAT 



for demonstralint; all the properties ami 

 practical applications of the gyrostat. 



GYROST ATIC PEN DULUM 

 GRAY'S GYROSTATIC MODELS 



As demonstrated at the Physical Society. 

 PRICES O.V .4 y PLICA TTOX. 



Kemble St. 



KINGSWAY London, W.C. 



NEW APPARATUS FOR 



PHOTOMICROGRAPHY 



!tal or Vertical Positic 



LARGE EPIDIASCOPE 



and 



for Ihe Dil 



nt apparatu 



Projection in Natural Colours of Microscopical 

 Slides, Opaque Objects (such as Book Illustra- 

 tions, Photo Prints, Diagrams, portions of Plants, 

 Skin Diseases, &c.), Lanletn Slides, and Spectra. 



LEITZ-EDINGER 



DRAWING APPARATUS 



For the Direct Projection of Microscopical Pre- 

 parations. Ensures greater accuracy in drawing. 



Catalogues and Booklets post free. 



E. LeiTZ (London), 



18 BLOOMSBURY SQUARE, W.C. 



(.-I /t-.u doors from Ihc British MuseMu.) 



NEGRETTI & ZAMBRA'S 



Standard Meteorological Instruments. 



Illustrated Price List sent free by post. 



38 Holborn 



Viaduct, 

 London, E.G. 



„»o*o*o«o«9£a 



