A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



" To the solid ground 

 Of Nature trusts the mind which builds for oye/'^VVoRDSWOPTH. 



No. 1867, Vol. 72] 



Registered as a Newspaper al the General Post Office.] 



THURSDAY, AUGUST 10, 1905 



[Price Sixpence 



[All Rights are Reserved 



NE 



VvJITON ^ CO.'S 



GARDEN 



SUN=DIALS. 



;=^gi^gT__, Terra-Cotta Pede<ital, 



luted with a loi" Porcelain 



Dial," 



£4 8 O. 



Fluted Pedestal with Si" Dial 



complete, 



£2 17 6. 



New Illustrated Catalogue, 

 32 pages, post free. 



RUBENS' LINEAR THERMOPILE. 



JOHN J. GRIFFIN & SONS, Ltd., 



MAKERS OF SCIENTIFIC INSTRUMENTS, 



Chemical and Scientific Instrument Makers to His Majesty's 



Government (Indian, Home, and Colonial). 



LABORATORY FURNISHERS and MANUFACTURING CHEMISTS. 



CHEMICAL AND PHYSICAL BENCH, illustrated above, as supplied 



to National Physical Laboratory, Teddington, titled for Gas, Water 



and Electricity. 



Catixlofiie nf Chemical and Physuat Apparatus, 350 //. and 1200 



Ilhistratians. free on a/'pticatiotl. 



De 



14 COMMERCIAL STREET, LEEDS. 



NEGRETTI & ZAMBRA'S 

 LONG RANGE 



BAROMETERS. 



THE GLYCERINE BAROMETER. 



This Barometer has a tube containing both Mercury fnd 

 Glycerine. The lighter soecific gravity of the latter ami 

 the difference 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 tji an inch being easily read 

 without the aid of any vernier or magnifier. 



Further "Particulars and Trices of this and other 



long range "Barometers sent on application 



to the Manufacturers — 



NEGRETTI & ZAMBRA, 



38 HOLBORN VIADUCT, E.C. 



branches: 45 CORNHILL, and 122 REGENT 

 STRHEl, LONDO.V. 



