A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



" To the solid ground 

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



No. 1862, Vol. 72] 



THURSDAY, J ULY 6. 1905 



Registered as a Newspaper at the General Post Office.] 



[Price Sixpence 



[All Rights are Reserved. 



NElflZ^TOM <Sc CO., 



SCIENTIFIC INSTRUMENT MAKERS 



To H.M. THE KING, H.R.H. THE PRINCE OF WALES and 



the GOVERNMENT, 



3 FLEET ST., LONDON, E.G. 



THE 



ASHE=FINLAYSON 

 COMPARASCOPE. 



For viewing two specimens side by side in 



the field of view of one microscope for 



comparison purposes. 



rtirficiilfirs on npplicfrfion. 



R. & J. BECK, LI2:: 



68 CORNHILL, LONDON, E.C. 



THE "IDEAL" LABORATORY 

 CLAMP. 



Special 

 Tamnhtet. ^^ 



^N. G. PYE <& CO., 



SCIENTIFIC INSTRUAIENT MAKERS, 



GRANTA WORKS, CAMBRIDGE. 



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 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 100th of an inch being easily read 

 without the aid of any vernier or ma-nifier. 



Further Particutars and Prices p/ 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 

 STREET, LONDON. 



