A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



" To the solid ground 

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



No. 1 86s, Vol. 72] 



THURSDAY, JULY 27, 1905 



[Price Sixpence 



Registered as a Newspaper at the General Post Office.] 



The above Lxntern his i cicir 1 ise 1 o;\ril and is li 

 5 in C nrlensers. 



NEWTON & CO., 3 FLEET ST.. LONDON. 



RUBENS' LINEAR THERMOPILE. 



JOHN J. GRIFFIN & SONS, Ltd., 



REYNOLDS & BRANSON, Ltd. 



Chemical and Scientific Instrument IVIal<ers to 

 H.M. Government (Indian, Home and Colonial). 



LABORATORY FURNISHERS AND MANUFACTURING CHEMISTS. 



RADIUM ROD„ 



This consists of a metal handle with Ebonite Top having a 



removable Aluminium Cap covering the RADIUM 



PREPARATION. 



With this all the Physical Properties of Radio-activity can readily 

 be shown. 



Price £4 15s. ^" ^itr* 

 X4 Connimex>ci£Ll St., Z^eecls. 



NEGRETTI & ZAMBRA'S 

 LONG RANGE 



BAROMETERS. 



THE GLYCERINE BAROMETER. 



This Barometer has a tube containing both Mercury and 

 Glycerine. The lighter specific gravity of the latter and 

 the diflference in the bore of the tube in which it rises and 

 falls increases the scale to about S inches for each inch of 

 the ordinary mercurial column. 



By means of this interesting instrument the smallest 

 variations in the atmospheric pressure are quite notice- 

 able, differences of looth of an inch being easily read 

 without the aid of any vernier or macnifier. 



Further Particulars and Prices of this and other 



long range "Barometers sent on application 



to the Manufacturers— 



NEGRETTI & ZAMBRA, 



38 HOLBORN VIADUCT, E.G. 



Branches: 45 CORNHILL, and 122 REGENT 

 STREET, LONDON. 



