A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

 Of Naiure ttvsis the mind which builds for aye."— Wordsworth. 



No. 1652, Vol. 64] 



THURSDAY, JUNE 27, 1901. 



Registered as a Newspaper at the General Post Office.] 



NEWTON & CO.'S 



PATENT 



" DEMONSTRATOR'S " LANTERN, 



FOR LIMELIGHT OR ELECTRIC. 



With Prism for Erecting, 

 and for Vertical Projection. 



Price £10 10s. 



3 FLEET ST., 

 LONDON. 



T he most simple 

 II and efficient 

 |i Single Lantern 

 ;! yet constructed 

 -1 for general 

 --f scientific work. 



''i NEW CATALOCUE 



W ofLanterns.Pro- 

 jection Appara- 

 tus and Slides, 

 Post Free, 



6 Stamps. 



"LONDON" 



MICROSCOPE. 



With Eye -piece | inch, \ inch 



Object - glasses, in Mahogany 



Case, 



£5 12s. 6d. 



Diiuble Ni«e-piecc, 9;- extra. 

 Focussing Substage, 14.'6 extra. 



R. & J. BECK, Ltd., 

 68 CORNHILL, 



[Price Sixpence. 



[All 'Rights are Reserved. 



VERLAG VON OUSTAV FISCHER IN JENA. 



Soeben erschien : 



DIE REDUKTION DER CHROMOSOMENZAHL 



UND DIE IHR FOLGENDEN KERNTEILUNGEN IN 



DEN EMBRYOSACKMUTTERZELLEN DER 



VON 

 F. SCHN I;E W IN D - TH IE S. 



Mit 5 Lithographischen Tafeln. 

 Preis : 7 Mark. 



NEGRETTI & ZAMBRA'S 



IMPROVED 



SELF-RECORDING RAIN- 

 GAUGES, BARGIVIETERS & 

 THERMOMETERS, 



Giving continuous Records 



on Charts wliich only require 



changing weeicly. 



Invaluable to Invalids and 



others unable to take daily 



readings. 



Illustrated Price List of Instruments free by Post to all 

 parts of the World. 



NEGRETTI & ZAWIBRA, 

 38 HOLBORN VIADUCT, E.G. 



Branches : 45 CORNHILL, and 122 REGENT STREET. 

 AWARDED TWO GOLD MEDALS PARIS EXHIBITION 1900. 



