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^"'^^■'^'"' /fif^l 



A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



" To the solid ground 

 Of A'aliin- trials the mind -which builds for oj'f.''— WORDSWORTH. 



BT e: -w T o »a" sz. co., 



SCIENTIFIC INSTRUMENT 



MAKERS 



TO HER MAJESTY THE 



QUEEN 



AND THE GOVERNMENT. 



&c. 



Catalogue of 

 OPTICAL LANTERNS. 

 PROJECTION APPARA- 

 TUS, and SLIDES, M. 

 WIMSHURST ELECTRICAL MACHINES. 



Kest Duality, i2in.,7oj. ; 15 in., i;5 loJ- ; 18 in., (.6 ^as. Multiple-Plate 

 Machines, ji^a to .£150. As made for the Science and Art Depart- 

 ment antl the Universities of Oxford, Cambridge, London, Sydney, 

 N.S.W., McGiU, Montreal, &c. 



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



NEW 



MICROSCOPE 



THE 



BRITISH STUDENTS." 



Microscope Stand No. 55, as 

 figured, with Iris Diaphragm, 

 One Eye-piece ; Double Nose- 

 piece, T-wo Object-glasses, 2/3" 

 and 1/6", adjusted to be In 

 about focus, and the Tvhole 

 packed In polished Mahogany 

 Case, 



£6:8:6 



No, 55- 



R. & *J. BECK, Ltd. 



68 CORNHILL, LONDON, E.C. 



BROWNING'S PliATYSCOPIC LENS. 



With Larger Angles, Increased Field, and Improved Definitiom 



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 observer of 

 Nature ought to do)."— Grant Alien in Knazvle.ige. 



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

 mologists, as it focuses about three 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 lo, 15, 20, and 30 diams. ; the lowest power, having the largest 

 field, is the best adapted for jjenerai use. 



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



Price o/' the Platyscofic Lens, mounted in Tortoiseshell, magnifying either 



10, 15, 20, or ^o diameters, each power, 15s. 



In nickelised German Silver, each power, 17s. 6d. 



Illustrated Description sent free. 



JOHN BROWNING, 63 STRAND. L ONDON, W.C 



SPECTACLES 

 ELECTRIC LIGHT, INCANDESCENT GAS. 



And other Powerful Illuminants. 



NEGRETTI & ZAMBRA'S 

 THERMOSCOPIC LENSES 



Protect the Eyes from Glare, and 

 RENDER THE LIGHT SOFT AND COOL. 



[llustrated Price Lists 0/ Optical and Meteorological Instruments 

 Free Iv Post to all parts of the World. 



NEGRETTI AND ZAMBRA, 

 SCIENTIFIC INSTRUMENT MAKERS to THE QUEEN, 



38 HOLBORN VIADUCT, E.C. 



BRANCHES : 45 CORNHILL; 122 REGENT STREET. 



