A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE 



" To the solid ground 

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



No. 1876, Vol. 72] 



THURSDAY, OCTOBER 12. 1905 



[Price Sixpence 



Newspaper at the General Post Office.] 



'DEMONSTRATOR'S" 

 OPTICAL LANTERN. 



The above Lantern has a clear base board and is fitted with 

 5-in. Condensers. 



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



THE NEVS^ 



"LONDON" 



MICROSCOPE. 



With Eye-piece | inch, J inch 



Object - glasses, in Mahogany 



Case, 



£5 12s. 6d. 



Double Nose-piece, 9/- extra. 

 Focussing Substage, 14/6 extra. 



R. & J. BECK, Ltd., 



68 CORNHILL, 

 ILm O Ta T> O T»S . 



NEW EDITION OF MARSHALL, AND 

 HURST'S " ZOOLOGY." 



Just Published, SIXTH EDIirON, Revised by F. W. GAMBLE, D.Sc, 



Lecturer in Zoology in ihe University of Manchester. 



With Illustrations. Crown 8vo. 10s. 6d. 



A JUNIOR COURSE OF 

 PRACTICAL ZOOLOGY. 



By ihe late 



A. MILNES MARSHALL, M.D., D.Sc. M.A., F.R.S.» 



Professor in ihe Victoria University ; Beyer Professor of Zoology 

 in Owens College ; .ind the late 



C. HERBERT HURST, Ph.D., 



Lecturer in the Victoria University, &c. 



London: SMITH, ELDER & CO., 15 Waterloo Pla 



S.W. 



NEGRETTI & ZAMBRA'S 

 LONG RANGE 



BAROMETERS. 



THE GLYCERINE BAROMETER. 



This Barometer has a lube 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 8 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 



'itho 



the aid of any 





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. 



