A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

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



^5^ian Instil 

 F£B85iaU 



No. 2259, Vol. 90] 



THURSDAY, FEBRUARY 13, 1913 



[Price Sixpence 



Newspaper at the General Post Office.] 



[All Rights Reserved. 



John J. GRIFFIN &SOf 



MAKERS OF 



Physical Apparatus 



THE GRAY-BURNSIDE 



MOTOR GYROSTAT 



for demonstrating all the properties and 

 practical applications of the gyrostat. 



GYROST ATIC PEN DULUM 

 GRAY'S GYROSTATIC MODELS 



As demonstrated at the Physical Society. 

 PRICES Oy AMPLICATION. 



Kemble St. 



KINGSWAY 



London, W.C. 



•RYSTOS" STILL. 



Improved Central Flue Water Still and Condenser. 



In this pattern the heat is conducted throueh the water by means of 

 a central tube ensuring economy of heatiuE;. The condenser worm is of 

 pure tin, and the water jacket is air-cooled on two surfaces. One gallon 



size (i litre distilled water per hour), solid copper £2 12 6 



Ring Burners for same ... i exira £0 6 6 



Cotalogues'-Vost Free. 

 14 CoxYknrKex?c:i£Ll S<:lTe^t. Ueecis* 



A new 

 Rain Gauge 



