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Kzb'b 



7 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the- solid ground 

 OJ Naliire trusts lie mind which Iniilds for aye." — WOKDSVVORTH. 



JVEAT^TOaV^ «SC CO., 



CIENTIFIC INSTRUMENT 



MAKER.S 



TO HER MAIESTY THE 



QUEEN 

 AND THE GOVERNMENT 



I.OSOPHICi 



r Makers 



I'OINTMEN 



. In.s 



Makers of every descrip- 

 tion of OPTICAL and 

 PHYSICAL APPARA- 

 TUS of the highest class, 

 for Colleges, Institutions, 



Cat.ilogiie of 

 OPTICAL LANTERNS, 

 PROJECTION APPARA- 

 TUS, and SLIDES, bd. 



WIMSHURST ELECTRICAL MACHINES, 



Best Quality, 12 in., 70^.-; 15 in., ^£5 

 M:>chines, ^20 

 ment, .-md the 

 N.S.W., McGill, M 

 3 FLEET STREET, TEMPLE BAR, LONDON, E.G. 



/150 



, . , I610S. Multiple-Plate 



made for the Science and Art Deparl- 

 of O.\ford, Cambridge, London, Sydney, 



NEW 



MICROSCOPE 



THE 



"BRITISH STUDENTS." 



Microscope Stand No. 55, as 

 figured, Tvlth Iris Diaphragm, 

 One Eye-piece ; Double Nose- 

 piece, Two Object-glasses, 2/3" 

 and 1/6', adjusted to be in 

 about focus, and the w?hole 

 packed in polished Mahogany 

 Case. 



£6:8:6 



R. & J. SECK, Ltd. 



68 CORNHILL, LONDON, E.C. 



BROWNING'S PLATYSCOPIC LENS. 



With Larger Angles, Inci eased Field, and Improved Definition 



of 



Em^rnveil Real Size. 

 AN ACHROMATIC COMBINATION, 



COMBINING THE DEFINITION OF A MICROSCOPE WITH THE 

 PORTABILITY OF A POCKET LENS. 

 " If you carry a small Platyscopic Pocket Lens (which every ob: 

 Nature ought to do)." — Grant Allen in Kfiowledge. 



The Platyscopic Lens is invaluable to botanists, mineralogists, or ento- 

 mologists, as it focuses about 'tliree times as far from the object as the 

 Coddington Lenses. This allows opaque objects to be examined easily. 



The Platyscopic Lens is made of four degrees of power, magnifying 

 respectively 10, 15, 20, and 30 diams. ; the lowest power, having the largest 

 field, is the best atlapted for general use. 



^he Lenses are set in Ebonite Cells, and mounted in Tortoiseshell Frames. 



iPrice of the Platyscopic Lens, iirounted hi Tortoiseshell, iitagnifying either 



10, 15, 20. or -^o diameters, each p07ver, 15s. 



In nickelised German Silver, each /•o-.n-r. 17s. 6d. 



Illustr.-tted Description sent free. 



JOHN BROWNING. 63 STRAND. LONDON, W.C- 



SPf,::CTACLES 

 ELECTRIG LIGHT, INCANDESCENT GAS. 



And othei^ Powerful Illuminants. 



NEGRETTI & ZAMBRA'S 

 THERMOSCOPIC LENSES 



I'lotect the Lyes from Clare, and 



RENDER THE LIGHT SOFT AND COOL. 



Illustrated Price Lists of Optical and Afeleorolosical Instruments 

 Free l-y P^t to all parts ol the World. 



NEGRETTI AND ZAMBRA, 

 SCIENTIFIC INSTRUMENT MAKERS to THE QUEEN, 



38 HOLBORN VIADUCT. E.C. 



BRANCHES: 45 CORNHILL ; 122 REGENT STREET. 



