7- 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



To the solid ground 



[JAL MCES&WEJG Hre] 



John J. Griffin & Sons, L 



KEMBLE ST., KINGSWAY, 

 LONDON, W.C. 



Scientific Instrument makers. 



The GRAY-BURNSIDE 



MOTOR - GYROSTAT 



With 10 attachments for demonstrating all the pro- 

 perties and practical applications of the Gyrostat. 



Descriptive Booklet, with Prices, on Application. 



Gyrostatic Pendulum. 



GRAY'S GYROSTATIC MODELS 



Prices on Application. 



REYNOLDS &. BRANSON, Ltd. 



RYSTOS" MICROSCOPE 

 PLATFORM 



Gold Medals:— 

 London, 1908. 



Allahabad. 1911. 

 Srand Prix. Turin, 1911 

 2 Medals. York. 1912. 



For use with the Stroud & Rendell Science Lanterns. This platform 

 is adjustable, so that any ordinary microscope (the draw tube being 

 removed) can be used for projection work. The platform can be raised 

 or lowered in order that the optical centre of the microscope may 

 coincide with that of the lantern £17 6 



Microscope as figured, wirh eyepiece and l" and J" objectives... 7 5 



\" objective for projection purposes ... ... ... ... ... 10 



Catalogue of Optical Lanterns and descriptive circular of Accessory 

 Apparatus for the S. &■ R. Lanterns, post free. 



14 COMMERCIAL, STREET. LEEDS. 



The Nesting Season ! 



For Watching Birds 

 The " Folding Minim " 

 is an ideal 

 Ready for use. Naturalist's Binocular. 



It combines the keenest definition, extra 

 wide field, magnification of 5j, and 

 ample illumination ; yet is easily carried 

 in a pocket. Price £7 10 



Full description will be senl post free on request. 



NEGRETTI & Z AM BRA, 



Holborn Viaduct, London, E.C. 

 City Branch: 45 Cornhill, E.G. 

 West End: 122 Regent St., W. 



Ready for placing in case, or pocket. 



